12th physics (vol 1)

1 BHARATHIDASANAR MATRIC HIGHER SECONDARY SCHOOL, ARAKKONAM_12th Physics Additional Questions

BHARATHIDASANAR MATRICULATION

HIGHER SECONDARY SCHOOL, ARAKKONAM.

12th STANDARD PHYSICS ADDITIONAL QUESTIONS ADDITIONAL 1 MARK QUESTIONS WITH KEY

ANSWERS

VOLUME - I

Created by Department of Physics Ph: 91-9380899694


1.ELECTROSTATICS

1.When a glass slab in introduced between two charged spheres, the force between them a) in increases b) remains same c) is reduced d) is increased or decreased, depending on the thickness of slab 2.Two charged spheres A and B are separated by a distance. If a third charged sphere C is brought near to them , then the force between A and B a) increases b) decreases c) remains same d) either increases or decreases depending on nature of charge in C. 3.Two point charge +3µC are separated by a distance of 0.4m . Where should a third charge +2µC be placed from +3µC .So that it experience s zero force. a) 0.4m b) 0.5m c) 0.2m d) 0.1m 4.Two charges 250µC and 120µC placed 15mm apart in medium repel each other with 105N. Then the value of dielectric constant. a) 14 b) 16 c) 13 d) 12 5.Charges 1mC, 0.5mC, -1mC -0.5mC are placed at four corners of square ABCD of sides1.414m. The electric field at the centre of the square must be a) 95x106 NC-1 along AB b) 35x106 NC-1 along BC c) 35x106 NC-1 along AB d) 95x106 NC-1 along BC 6.Two point charges +8µC and +4µC repel each other with a force 16N.If a charge of -6C is given to each other , what will be the force now, a) 4N(attractive) b)4N(repulsive) c) 2N(repulsive) d) 2N(attractive) 7.In an microwave oven ,heat is produced due to a) oscillating of water molecule b)oscillating torque on water molecules c) molecular reaction of current by thermodynamic heating d)breaking of bonds in water molecule 8.If a proton is moved against the coulomb force of electric field a) work is done by electric field b) energy is supplied from outside source c) energy of proton is decreased d) strength of electric field decreased


9.Two point charges 8C and 2C are separated by a distance of 9 cm. The point where the electric field becomes zero is a) 6 cm from 8C b) 3 cm from 2C c) 3 cm from 8C d) both(a)and (b) 10.Two ideal spheres of charges8C and -4C are 0.02 m apart. They are brought in conduct and then replaced to their original position, the ratio of force between them before and after contact is a) 4:1 b) 1:8 c) 1:4 d) 8:1 11.Two protons repel each other with a force of 22.5 N ,the distance of separation is a) 3.2x10-12 m b) 3.2x10-14 m c) 3.2x10-15 m d) 3.2A0 12.How a charge of 9C is divided into two parts to have a maximum force of repulsion when separated by certain distance a) 6C,3C b) 8C,1C c) 5C,4C d) 7C,2C 13.The force between two charges in vacuum is 0.1N. What is the force if the vacuum is replaced by a medium of permittivity 10 times vacuum, a) 1N b) 0.01N c) 10N d) 0.001 N 14.The ratio of electric field intensities at a distance “ r ” from the centre of a small dipole along axial and equatorial line is a) 1:2 b) 1:4 c) 4:1 d) 2:1 15.A body charged to 4.8x10-20C by applying a potential difference of 500 mV. This is a) true because body can store charge b) false , because potential difference applied is not enough c) false, because charge must be integral multiple of electron d) true, because charge is directly proportional to potential difference. 16.Two point charges separated by distance d1exerts force F1 and distance d2 the force is F2 , then, a) F1d2 = F2d1

2 b) F12

d1 = F2d22 c) F1

2 d2 = F2

2 d1 d) F1d1

2 = F2

2 d2

2 17.The effective capacitances of two capacitors connected in parallel is equal to the a)product of the capacitances b) differences between the capacitors c) the ratio between the capacitance d) sum of the capacitances 18.The force of attraction between two spheres of charge q and -q is F. If two spheres are brought into contact and then separated to twice the previous distance the force now,


a) F/2 b) F/4 c) 4F d) zero 19.Work done for rotating the dipole in an electric field is a) kinetic energy b) potential energy c) total energy d)each of these 20.Which one is the application of electric potential energy of an electric dipole in electric field a) capacitor b) inductor c) room heater d) microwave oven 21.The negative gradient of potential gives the magnitude of the a) electric field b) magnetic field c) magnetic flux d) electric flux 22.The quantity which is same at all points in an equipotential surface is a) potential b) current c) charge d) mass 23.The equipotential surfaces of an isolated point charge are a) concentric spheres b) square c) cylindrical d) triangle 24.Work done in moving a point charge between two points on an equipotential surface is a) zero b) one c) maximum d) minimum 25.Electric field lines are … to an equipotential surface a)normal b) parallel c) 450 d) zero 26.The equipotential surfaces for a uniform electric field are a) parallel planes b) tangential planes c) normal planes d)cleavage planes 27.The work done in moving 500µC charge between two points on equipotential surface is a) zero b) finite ,positive c) finite , negative d) infinite negative 28.A charge Q is placed at the centre of a cube. The electric flux through all the 6 faces of the cube is a) Q/60 b) Q/80 c) Q/0 d) zero 29.Capacitor stores a) magnetic energy b) chemical energy c) electrical energy d)heat energy 30.A hallow insulated conducting sphere is given by a positive charge of 10 µC. What will be the electric field at the centre of the sphere, if its radius is 2m? a) zero b) 5 µC m-2 c) 20C m-2 d) 32 µC m-2 31.Capacitors use the principle of a) self induction b) mutual induction c) electrostatic induction d) dielectric polarization


32.The capacitance of a conductor does not depend upon a) its geometry b) material by which plates are made c) nature of medium d) area of the plates 33.An air filled parallel plate capacitor connected to a battery and allowed to charge. If a dielectric slab is placed between the plates of the capacitor a) the charge on the capacitor remains un changes b) the charge on the capacitors increases c) the voltage across the plates of the capacitor increases d) the capacitance of the capacitor decreases 34.On a conductor the surface charge density at a point is a) directly proportional to the radius of curvature b) inversely proportional to the radius of curvature c) independent of radius of curvature at that point. d) zero 35.If a Gaussian surface encloses a dipole of moment 2qd, then the total flux through the surface is a) q / 0 b) 2q/0 c) q/20 d) zero 36.Work done in giving a charge of 8x10-12C on a condenser of capacity 100µF is a) 32x10-32J b) 32x10-20J c) 8x10-12J d) 4x10-32J 37.Two charged metal spheres of radii 2 cm and 5 cm are connected by a wire. The ratio of the surface charge densities is a)2.5 b) 0.4 c) 12.5 d) 5 38.The capacitance of a parallel plate capacitor is 8 µF. If the surface area is doubled and the distance between the plates is halved .Then what will be the capacitance of the condenser? a) 12 µF b) 32 µF c) 4 µF d) 8 µF 39.Relative permittivity of vacuum is a) 3 b) 1 c) 2 d) 0 40.The charge that can be stored in 50 µF capacitor connected to source of potential difference of 20V is a) 102C b) 10-3C c) 1C d) 103 C 41.An infinite charged plane sheet produces a field of 2x105NC-1 at a distance of 5 cm, the surface charge density is a) 3.54x10-6Cm-2 b) 3.54x10-6Cm c) 0.54x10-2Cm d) 18.53x10-3Cm 42.A device not working with the principle of electrostatic induction is a) van de Graff generator b) microwave oven


c) lightning arrestor d) (a) &(b) 43.A parallel plate capacitor connected to a 12V source is charged to 21 µC if the capacitor is filled with an oil of dielectric constant 3, then the charge stored is a) 7 µC b) 63µC c) 14 µC d) 57 µC 44.The equivalent capacitance of two capacitors in series is 1.5µF. The capacitance of one of them is 4µF .The value of capacitance of other is a)2.4µF b) 0.24µF c) 0.417µF d) 4.17µF 45.If the distance between two protons in uranium atom is 9x10-15m, then the mutual electric potential energy between them is a) 9x10-14J b) 1.44x10-15J c) 2.56x10-14J d) 1.6x10-5J 46.Torque on a dipole in a uniform electric field is maximum when angle between P and E is a) 00 b) 900 c) 450 d) 1800 47.Potential energy of two equal negative point charges of magnitude 2 µC placed 1m apart in air is a) 2J b) 0.36J c)4J d) 0.036J 48.An electric dipole placed at an angle in a non-uniform electric field experiences a) neither a force nor a torque b) torque only c) both force and torque d) force only 49.Which of the following is not a dielectric ? a) ebonite b) mica c) oil d) gold 50.The electric field intensity at a distance r due to infinitely long straight charged wire is directly proportional to a) r b) 1/r c) r2 d) 1/r2 51.An electric dipole moment P is placed in a uniform electric field of intensity E at an angle with respect to the field . The direction of the torque is a) along the direction of P b) opposite to the direction of P c) along the direction of E d) perpendicular to the plane containing P &E 52.The capacitance of a capacitor is a) directly proportional to the charge q given to it b) inversely proportional to its potential V c) directly proportional to q and inversely proportional to V d) independent of both the charge q and potential V


53.The intensity of electric field at a point is equal to a) the force experienced by a charge q b) the work done in bringing unit positive charge from infinity to that point c) the positive gradient of the potential d)the negative gradient of the potential 54.The unit of the number of electric lines of force passing through a given area is a) no unit b) NC-1 c) Nm2C-1 d) N m 55.A dielectric medium is placed in an electric field E0.The field induced inside the medium a) acts in the direction of the electric field b) acts opposite to E0 c)acts perpendicular to E0 d) is zero 56.A non-polar dielectric is placed in an electric field (E) . Its induced dipole moment a) acts perpendicular to E b) acts in the direction of E c) acts opposite to the direction of E d) is zero 57.When the charge given to a capacitor is doubled , its capacitance a) increases twice b) decreases twice c) increases four times d) does not change 58.Two point charges +q and –q are placed at A and B separated by small distance. The electric field intensity at the midpoint o of AB a) zero b) acts along AB c) acts along BA d) acts to AB 59.An electric dipole of dipole moment (P) is kept parallel to an electric field of intensity E. The work done in rotating the dipole through 900is a) 0 b) –PE c) PE d) 2pE 60.The capacitance of a parallel plate capacitor given a charge q is C. If the charge on the capacitor is doubled then the capacitance of the capacitor is a) C b) 2C c) C/2 d) 2/C 61.The accumulation of charge in a charged conductor is maximum at a) a point where the curvature is maximum b) sharp points c) a point where the radius is minimum d) all the above 62.Radius of conductor is r and its charge density is , then a) r b) 1/r c) 1/r2 d) r2 63.In microwave oven, the water molecules are excited by a) force b) oscillating torque c) oscillating force d) a torque


64.Which molecule do not have a permanent dipole moment? a) N2O b) NH4 c) H2O d) O2 65.In electrostatic induction a) like charges were induced at the near end b) only unlike charges were induced c) unlike charges induced at near end and like charge induced at far end d) only like charges were induced 66.In a parallel plate capacitor, the electric field at any point between the plates does not depend on a) distance between the plates b) charge on the plates c) area of the plates d) the dielectric media between the plates. 67.In a thin , non conducting infinite plane sheet 1.6µC charge are present in the area2mm2.Calculate the surface density a) 8C/m2 b) 0.8C/m2 c) 32x103C/m2 d) 2.25x10-6C/m2 68.The force between two charges in a medium of dielectric constant D and in the air is a) 1:D b) 1:D2 c) D:1 d) D2:1 69.The charges in the electrostatic field are analogous to which in a gravitational field a) distance b) forces c) masses d) points 70.Two copper spheres A and B of same size are charged to same potential. A is hollow and B is solid. Which of the two fields holds more charge? a) solid sphere cannot hold any charge b) both have the same charge c) hollow sphere cannot hold any charge d) both have zero charge 71.The relative permittivity is one for a) glass b) mica c) air d) earth 72.The repulsive force between two like charges of 1 coulomb separated by a distance of 1 m in vacuum is equal to a) 9x109 N b) 109N c) 9x10-9 N d) 9N 73.When air is replaced by dielectric medium of dielectric constant K, the maximum force of attraction between two charges separated by a distance a) becomes K-1 times b) decrease K2 times c) remains unchanged d) increases K times 74.Which of the following does not have a permanent electrical dipole


moment? a) ammonia b) water c) nitrogen d) carbon di oxide 75.Normally the charge of a substance is a) having any value b) a constant c) an integral multiple of the charge of an electron d) is an integer 76.In an equipotential surface which is same at all points a)electric intensity b) electric force c) electric potential d) electric flux 77.A bird sitting on a high power line a) gets killed instantly b) gets a mild shock c) is not affected practically d) gets a fatal shock 78.An electron initially at rest is accelerated through a potential difference of 1 volt. The energy acquired by electrons is a) 1J b) 1.6x10-19 J c) 10-19 J d) 1.6x1019 J 79.In bringing an electron ,towards another electron, the electrostatic potential energy of the system a) remains constant b) becomes zero c) increases d) decreases 80.Four dipoles of charges of magnitude +e and –e are placed inside a cube. The total electric flux coming out of the cube will be a) 8e/0 b) 16e/0 c) e/0 d) zero 81.The direction of electric field due to an infinitely long straight positively charged wire is a) radially inward b) along the length of the wire c) radially outwards d) none of the above 82. The direction of electric field due to an infinitely long straight nrgatively charged wire is a) radially inward b) along the length of the wire c) radially outwards d) none of the above 83.An electric dipole consists of a) two like and equal charges b) like and unequal charges c) unlike and equal charges d) unlike and unequal charges 84.When the charging source is disconnected , the charges given to the plates of an ideal capacitor a) increases b) decreases c) becomes zero d) remains the same 85.Increasing the charge on the plates of a capacitor means a) increasing the capacitance b) increasing the p.d. between the plates


c) both (a) and (b) d) none of the above 86.Three capacitors 2F, 5F and 3F are in parallel across 5V supply. The charge on each of them respectively are a) 12C,30C,18C b) 10C, 25C,15C c)8C, 20C,12C d) 6C,15C,9C 87.Capcity of the conductor depends upon a) size of the conductor b) thickness of the conductor c) material of the conductor d) all of these 88.A capacitor is a device for a) increasing voltage in the circuit ` b) increasing the current in the circuit c) storing the charges d) giving resistance to the current 89.A dielectric will have a) free electrons b) no electrons c) tightly bound electrons d) one electron in the outer orbit 90.A charged conductor with sharp points on its surface a) gains charge b) neither gains nor loose charge c) rapidly lose its charge d) gets rusted soon 91.A non-polar molecule acquires induced dipole moment a) opposite to the direction to the electric field b) perpendicular to the electric field c) in the direction of the electric field d) none of the above 92.In the absence of an external field , the net dipole moment of polar molecules is a) positive b) infinite c) negative d) zero 93.If a dielectric slab is introduced between the plates of a capacitor , the dielectric slab gets a) positive charge b) polarized c) negative charge d) neutralized 94.The number of electric lines of force produced by a unit charge in vacuum a)1/0 b) 1012/8.854 c) 36x109 d) all of these 95.When a glass slab is introduced in between the plates of a parallel plate air condenser, its capacitance will a) not change b) decreases c) increases d) tends to zero


96.The energy recovered if a capacitor is allowed to discharge is a) CV b) CV2 c) CV2/2 d) CV2/4 97.The energy stored in a charged capacitor is a) potential energy b) electrostatic potential energy c) electromagnetic energy d) magnetic energy 98.At the pointed ends of a conductor the curvature is a) minimum b) maximum c) zero d) none of the above 99.If R is the radius of curvature at a point, then curvature is a) R b) R2 c) 1/R d) 1/R2 100.A lightning arrestor has a sharp spike for the following reason a) it scares away birds b) charges leak away faster c) it conducts heat quickly d) it reduces vibration 101.By enclosing the sphere of Van de Graaff generator in a gas filled steel chamber at a very high pressure, which of the sphere is reduced a) potential b) charge c) leakage of charge d) volume 102.Which of the following cannot be accelerated using Van de Graaff generator? a) -particle b) electron c) proton d) deutron 103.The electric potential energy of a system consisting of two charges is directly proportional to the ……. of the two charges a) sum b) difference c) product d) ratio 104.The force between two charges ,when they are separated by a certain distance is ‘F’ N. When they are placed in medium, the distance of separation is halved to get the same force. What is the relative permittivity of the medium? a) 2 b) 4 c) 6 d) 5 105.The charge acquired by 5x1010 electrons a) 3.204x10-19 C b) 4.806x10-19 C c) 1.602x10-19 C d) 8.01 x10-19 C 106.The electric potential at a point at a distance7.5cm from an electric field25Vm-1 a) 1.75 V b) 1.875V c) 0.1875 V d) 17.5V 107.The permittivity of a medium having relative permittivity r=5 a) 4.427x10-11Nm2C-2 b) 1.786 x10-8Nm2C-2 c) 53.12 x10-12Nm2C-2 d) 1.8 x10-9Nm2C-2 108.The charges q1, q2 , q3 are lying within a closed surface and the charges q4, q5 , and q6 are lying outside the surface. Then the electric flux


linked with the surface is a) = 1/0 (q1+q2 +q3) b) = 1/0 (q2+q3 +q6) c) = 1/0 (q1+q3 +q6) d) =1/0 (q2+q4+q6) 109.The electric flux inside a hollow metallic sphere of radius 5cm is 8x103Nm2 C-1 .Find the amount of charge within the sphere a) 44.2 nC b) 88.54 nC c) 70.8 nC d) 40x103C 110.The capacitance of air filled parallel plate capacitor is 4F. If the distance between the plates is doubled and the space between the plates is filled with a dielectric material of dielectric constant 4 then its capacitance is a) 4F b) 32F c) 16F d) 8F 111.Find the ratio of the effective capacitance of two capacitors 5F and 10F .When they are connected in parallel and series a) 2:9 b) 9:2 c) 10:3 d) 3:10 112.The potential at a point on the earth is a) zero b) positive c) negative d) infinity 113.6F is the charge given to a thin infinite plate of area 3cm2. Find its charge density. a) 2x10-2Cm-2 b) 0.2x10-2Cm-2 c) 1.8Cm-2 d) 5x10-2Cm-2 114.Three capacitors are having equal capacitances 2F. Two of them are connected in series and the third one is connected parallel with them. What is the effective capacitance? a) 6F b) 3F c) 2F d) 4F 115.In the process of polarization of molecules , the dipole moment of … are aligned in the direction of external electric field a) permanent dipoles b) induced dipoles c) both (a) and (b) d) neither (a) and (b) 116.When an earthened conductor is moving away from a charged conductor , then the potential of charged conductor a) decreases b) increases c) does not change d) becomes zero 117.In a capacitor of capacitance 5F, the distance between the plates is halved and filled with a material of dielectric constant 5, then its capacitance is a) 12.5F b) 2F c) 10F d) 50F 118.When an earthened conductor moves towards a charged conductor ,the potential of the charged conductor


a) becomes zero b) increases c) decreases d) remains same 119.The electric field at a point on the surface of a hollow metallic sphere a) depends on the radius of the sphere b) is zero c) depends on the charge and radius of the sphere d) is constant 120.When a charged particle is moving against a repulsive force of electric field then the ……. of the substance increases a) kinetic energy b) electric potential energy c) mechanical energy d) magnetic energy 121.Addition nature of charge means, the total electric charge of a system is equal to a) the sum of positive charges b) the sum of negative charges c) algebraic sum of all charges d) zero 122.Which is not the unit of electric flux? a) Nm2C-1 b) V m c) A m d) A m2 123.When a negative charge is given to a conductor , the conductor a) gets decrease in the mass b) gets increase in its velocity c) acquires an electric potential d) sends an electric current 124.1volt/ metre equals a) 1N b) 1Nm-1 c) 1NC-1 d) 1JC-1 125.Potential difference between the plates of a capacitor is 5.65V. If the distance of separation is doubled , then potential difference is a)1.13V b) 2.825V c) 1.4V d) 11.3V 126.In a capacitor if the value of the dielectric constant r is increased then its capacitance will a)increase b ) decrease c) becomes zero d) becomes infinite 127.The effect due to charges outside the surface on the electric flux a) increases the flux b) decreases the flux c) does not change the flux d) reduces to zero 128.SI unit of electric charge is a) coulomb b) ampere metre c) volt second/ohm d) all the above 129.When two capacitors are connected in series to a source of emf , then each one of them will have same a) voltage b) electric field c) both (a) and (b) d) charge 130.Two point charges placed at a distance ‘r’ in the air experiences a certain force, then the distance at which they will experience the same force in the medium of dielectric constant K is


a) K r b) r/2 c) r/K d) r K 131.Electron in an electric field of 9.11x106V m-1 experiences an acceleration of a) 1.6x1016 ms-2 b) 1.6x1017 ms-2 c) 1.6x1018 ms-2 d)1.6x1019 ms-2 132.The work done in placing a charge of 8x10-18 C on a condenser of capacity 100F is a) 3.1x10-28 J b) 4x10-10 J c) 32x10-32 J d) 10x10-32 J 133.Two parallel plates with 5 cm separation are at p.d. of 0.5KV. Force acting on the electron between the plates is a) 4.6x10-5 N b) 3.6x10-15 N c) 2.6x10-15 N d) 1.6x10-15 N 134.On moving a charge of 20 C by 2cm, 2J of work is done , then the potential difference between the points is a) 0.5V b) 0.1V c) 8V d) 2V 135.The force of attraction between two charges +30x10-9C and -20x10-9C separated by a distance of 0.20m is 5x10-5N . find the relative permittivity of the medium a) 2.7 b) 2.1 c) 2.2 d) 2.5 136.In hydrogen atom the ratio of electrostatic and gravitational force electron and proton is a) 1 b) 2.27x1039 c) 2.27x10-39 d) 2\ 137.When a positive charge is brought nearer to a conductor the charge induced at the far end of the conductor is a) positive b) negative c) no charge d) unlike charge 138.Theforce between two electrons separated by a distance r varies as a) r2 b) r c) r-1 d) r-2 139.Calculate the force between the two charges of value 1C and they are separated by a distance of 1m in air is a) 1/40 b) 8.854x10-12 c) 1/40r d) 40 140.Two point charges of equal magnitude are separated by 12 cm in air. An attractive force of 90N acts on each charge. Then the two charges are a) -12mC and -12mC b) +12mC and -12mC c) +10mC and -10mC d) +6mC and -6mC 141.Two charges –q and +2q are placed at A and B respectively. Let AB =d. At a point P between A and B , the potential is zero. Then the distance AP is ….. a) d/4 b) d/3 c) d/2 d)2d/3 142.Two charged bodies of change +q, -3q are brought in contact and


separated . The charge possessed by each body after separation. a) –q , -q b) +q , -2q c) –q, +3q d) +q , +q 143.An electric charge residing on s body produces a) electric field b) magnetic field c) both electric field and magnetic field d) neither electric field nor magnetic field 144.The lower comb of Van de Graaff generator is maintained at a +ve potential of a) 10KV b) 10V c) 107V d) 100V 145.Over an equipotential surface , the electric field intensity is a) everywhere tangential to the surface b) zero c) everywhere normal to the surface d) tangential at some places and parallel at some other places 146.Number of lines of force per unit area is proportional to the \ a)magnitude of electric potential b) 1/0 c) magnitude of E d) magnitude of 0 147.The force between two charges in vacuum is 0.1N. What is the force if the vacuum is replaced by a medium whose permittivity is 10 times greater than that of vacuum. a) 0.1N b) 0.01N c) 0.001N d) 0.0001N 148.The minimum value of the charge on any object cannot be less than a) 1.6x10-19C b) 3.2x10-19C c) 4.8x10-19C d) 1C 149.A stationary electric charge produces a) only electric field b) only magnetic field c) both electric and magnetic field d) neither electric nor magnetic field 150.A surface enclosed an electric dipole , the flux through the surface is a) infinite b) positive c) negative d) zero 151.A positively charged glass rod attracts an object. The object must be a) negatively charged b) positively charged c) neutral d) either negatively charged or neutral 152.A charge q is located at the centre of a hypothetical cube. The electric flux through any space of the cube is a) q / 0 b) q / 20 c) q / 40 d) q / 60 153.If a glass rod is rubbed with silk , it acquires a positive charge because a) protons are added to it b) protons are removed from it c) electrons are added to it d) electrons are removed from it 154.Five balls numbered 1 to 5 are suspended using separate threads. Pairs


(1,2),(2,4) and (4,1) show electrostatic attraction , while pairs (2,3) and (4,5) show repulsion. Therefore, ball 1must be a) positively charged b)negatively charged c) neutral d)made of metal 155.A charge q1 exerts some force on a second charge q2. If a third charge q3 is brought near, then the force of q1 exerted on q2 a) will decrease in magnitude b) will increase in magnitude c)will increase if q3is of the same sign as q1 and will decrease if q1is opposite sign d) will remain unchanged 156.Two small spheres each carrying a charge q are placed r metre apart. One of the spheres is taken around the other one in a circular path, the work done will be equal to a) force between them x r b) force between them x 2nr c) force between them / 2nr d) zero 157.A hollow metal sphere of radius 5 cm is charged such that the potential on its surface is 10V. The potential at the centre of the sphere is a) zero b) same as at a point 5 cm away from the surface c) 10V d) same as at a point 25 cm away from the surface. 158.A body can be negatively charged by a) giving excess of electros to it b) removing some electrons from it c) giving some protons to it d) removing some neutrons from it 159.Three charges +3q, +q and Q are placed on a straight line with equal separation. In order to make the net force on q to be zero , the value of Q will be a) +3q b) +2q c) -3q d) -4q 160.Charges reside on the a) outer surface of the charged conductor b) inner surface of the charged conductor c) inner as well as outer surface of the charged conductor d) none of the above 161.The unit of electric permittivity 0 is a) farad/metre b) volt / metre c) coulomb / farad d) coulomb/m2 162.There are two charges +1C and +5C separated by a certain distance d. The ratio of forces acting on them will be a) 1:5 b) 1:1 c) 5:1 d) 1:25 163.The potential at any point inside a charged sphere is a) zero b) smaller than the potential on the surface


c) greater than the potential on the surface d) same as potential on the surface 164.Two conducting spheres of radii r1 and r2 are equally charged . The ratio of their potentials is a) r1

2 / r22 b) r2

2 / r12 c) r1 / r2 d) r2 / r1

165.Two condensers of capacity C1 and C2 are connected in parallel . If a charge q is given to the assembly, the charge gets shared. The ratio of the charge on the condenser C1 to the charge on the condenser C2 is a) C1 / C2 b) C2 / C1 c) C1C2 d) 1 / C1C2 166.If a capacitor of capacitance 55 pF is charged to 1.6V , then the number of electrons on its negative plate is a) 55x107 b) 5.5x107 c) 550x107 d) 0.55x107 167. If total charge of the decay of an element is 92 e , then the total charge after decay is a) 41 e b) 91 e c) 92 e d) 184 e 168.If F and Fm are the force between two charges in air and medium then the ratio of F/Fm is called a) permittivity b) permeability c) charge d) relative permittivity 169. The total flux over a closed surface of charge q is a) 4q b) 36 x 109 q c) 9 x 109 q d) 4 x 109 q 170. If a positively charged plate is brought nearer to a negatively plate, then the potential difference between them will a) increase b) remain the same c) become zero d) decrease 171.If n identical capacitors each of capacity C are connected in series , then its equivalent capacity is a) n C b) 1/n C c) n / C d) C / n 172.The dielectric constant of a substance is 4 .The permittivity of that substance is a) 4 b) / 4 c) 4 0 d) 0 / 4 173.The capacitance of a parallel plate is maximum when the region between the plates are a) completely filled by dielectric material b)partially filled by dielectric material c)completely filled by air d) completely filled by conducting material 174.If the work done for moving a unit positive charge from a point X to another point Y is zero , then a) potential at X is less than potential at


b)potential at Y is less than potential at X c) potential at X is equal to potential at Y d) potential at X is positive whereas the potential at Y is zero 175.The imaginary surface drawn for determining the field at a point due to infinite plane sheet of charge is a) spherical b) plane c) cylindrical d) cubical 176.The surface charge density is more at a)less curvature b)greater curvature c) plane surface d)greater radius of curvature 177.The potential developed in the Van de Graff generator is used for a) domestic current supply b) industrial current supply c) nuclear reaction d) nuclear fusion 178.As the thickness of dielectric increases between the two plates then the capacity of the condenser a) decreases b) increases c) constant d) becomes zero 179.If the change of potential with respect to distance is given as V = r2-3r-5 then find electric field intensity at a distance 5 units a) 2 units b) 7 units c) 3 units d) 5 units 180.When air medium in capacitor is replaced by a medium of dielectric constant r the capacitance a) decreases r times b) remains the same c) increases r times d) increased by r

2 times 181.A certain region of space isolated from external electric field is known as a) electrostatic induction b) electrostatic shielding c) electrification d) charging 182.In Van de graff generator , the belt acquires charges from comb , by a) electrostatic induction b) electromagnetic induction c) conduction d) action of points 183.When a dipole is placed anti parallel to the electric field it has a) no potential energy b) minimum potential energy c) maximum potential energy d) finite potential energy 184.The electric field due to a helium nuclei at a point on its orbit of radius 0.25A0 is a) 4.608x103NC-1 b) 4.608x10-8NC-1 c) 4.608x1012 NC-1 d) none 185.The electric flux depends on


a) location of charge b) value of charge c) charge outside Gaussian surface d) both location and value 186.During lightning it is better a) to stand under tree b) to stand in a open space c) to run d) to sit inside a bus 187.When a dielectric is introduced in a parallel plate capacitor ,the induced electric field a) same direction as applied field b) perpendicular to applied field c) opposite to applied field d) 450 with field 188.When ‘n’ capacitors of equal capacitances are connected in parallel and series . the ratio of effective capacitance is a) 1;n2 b) n:1 c) n2:1 d) 1:n 189.Two charges 24C each of same polarity are separated by 200Cm.The force acting on another 4C charge placed at the midpoint on the line joining two charges be a) zero b) 31.44 N c)12.88N d) 44.32N 190.The force between two charges in air is F. This force becomes 13/25 F when placed in a medium at the same distance. The r of medium is a)13/5 b) 14/5 c) 25/13 d) 15/4 191.Two charged spheres of radius 15 cm and 20cm are connected by a thin wire. No current will flow if a) they have the same potential b) they have different potential c) they have equal charge d) they have unequal charge 192.If the radius of a conducting solid and conducting hollow sphere are the same which one can hold greater charge a)solid sphere b) hollow sphere c) both will hold equal charge d) hollow sphere will hold half the charge of solid sphere. 193.The dielectric constant K of an insulator can be a) b) zero c) -2 d) 6 194.In the direction indicated by an electrostatic field line a) the electrostatic field strength must increase b) the electrostatic field strength must decrease c) the electrostatic potential must increase d) the electrostatic potential must decrease 195.A proton is moved between two points whose potential difference is 30V. The kinetic energy acquired in eV is a) 30 eV b) 10 eV c) 20 eV d) 40 eV


196.An infinite charged plane sheet produces a field of 2x105 NC-1 at a distance of 5 cm. The surface charge density is a) 3.54x10-10 Cm-2 b) 0.35x10-6 Cm-2 c)3.54x10-6 Cm-2 d) 3.54 Cm-2

197.Charge per unit length is called a) charge density b) surface charge density c) linear charge density d) electric intensity 198.To eliminate sparking in the ignition system of automobile engines we use a) inductors b) resistors c) engine oil d) capacitors 199.Xerox copying machine is working on the principle of a) electric force b) magnetic force c) electrostatic force of attraction d) centripetal force 200.The electric potential energy of two point charges is not equal to a) the work done to assemble the charges b) force between the two charges c) work done in bringing each other d) work done in bringing a charge from infinite distances II. IMPORTANT UNITS 1.The unit of Coulomb force between the two point charges is ………. 2.The unit of permittivity is ………. 3.The unit of relative permittivity is ………. 4.The unit of electric charge is ………. 5.The unit of electric field intensity is ………. 6.The unit of electric dipole moment is ………. 7.The unit of torque is ………. 8.The unit of electric potential difference is ………. 9.The unit of electric flux is ………. 10.The unit of linear charge density is ………. 11.The unit of surface charge density is ………. 12.The unit of capacitance is ………. 13.The practical units of capacitance are ………. and ………. 14.Farad is equal to .......... 15.The unit of 1/40 is ……….


III. STANDARD VALUES 1.The charge of an electron is …. 2.Permitivity of free space 0 is …. 3. The value of 1/40 is ………. 4.Relative permittivity of air is …… 5. Permittivity of air is …… 6.The ratio of electrostatic force to gravitational force of attraction between an electron and a proton is ….. IV. IMPORTANT FORMULAE 1.Force between the two charges is……….. 2.Relative permittivity(dielectric constant ) is ………… 3.Amount of charge is …………. 4.Relation between the force in air and medium is ……….. 5.Relation between electric field and force is …………. 6.Electric field due to point charge is …………… 7.Electric dipole moment is …………. 8.Electric field due to an electric dipole at a point on its axial line is ……. 9. Electric field due to an electric dipole at a point on the equatorial line is … 10.Torque on a dipole placed in a uniform electric field is …….. 11.Electrical potential energy of a dipole is …….. 12.Electric potential energy of a point charges is ….. 13.Electrical potential at a point due to point charge is ………. 14. Electrical potential at a point due to an electric dipole is ………. 15.Electric flux according to Gauss’s law is ………… 16.Electric field due to plane sheet of charge q is ……… 17.Electric field at a point between parallel sheet of charge is ……… 18.Electric field due to an infinite long straight charged wire is ……. 19.Electric field due to uniformly charged spherical shell at a point outside the shell is …… 20. Electric field due to uniformly charged spherical shell at a point on the surface of the shell is …….. 21.Electric field due to uniformly charged spherical shell at a point inside the shell is….. 22.Capacitance of a conductor is ………..


23.The charge density is ……… 24.Capacitance of parallel plate capacitor is ……….. 25.Capacitance of parallel plate capacitor with dielectric slab is ………. 26. Capacitance of parallel plate capacitor completely filled with dielectric is 27. Relation between the capacitance in air and medium is ……….. 28.Work done by a charge is ………. 29.The effective capacitance connected in series is …….. 30. The effective capacitance connected in parallel is …….. 31.The capacitance of a capacitor contains n plates is ……… 32.The energy stored in a capacitor is ………. 33. Relation between electric field and potential is …………. 34.Electric potential energy of a system of two charges is ……. 35.Linear charge density is …….. 36.Surface charge density is ……….. 37.Molecular polarisability is ………

V.THREE MARK QUESTIONS 1. DEFINATIONS:

1. Define Coulomb. 2. Define electric field intensity at a point. 3. Define the electric potential at a point. 4. Define a dipole. 5. Define dipole moment. 6. Define molecular polarisability. 7. Define the unit of electrical potential difference. 8. Define one farad. 9 .Define capacitance. 10.Define electric flux. 11.Define dielectric polarization. 12.Define the effective capacitance of the capacitors connected parallel. 13.Define the effective capacitance of the capacitors connected series. 14.Define electrical potential energy. 2. LAWS AND PRINCIPLES 1.State the law of conservation of electric charge.


2.State Coulomb’s law in electrostatics. 3.State Gauss’s law. 4.What is known as electrostatic induction? 5.What is known as electrostatic shielding? 6.What is known as action of points? 7.What is the principle of capacitance? 3.USES.(APPLICATIONS) 1.Mention the applications of capacitor. 2.What are the uses of electrostatic devices? 3.What is the use of lightning conductor? 4.State the use of Van de Graff generator. 5.State the application of electrostatic force of attraction and repulsion. 4. PROPERTIES(CHARACTERISTICS) 1.Give any three properties of electric lines of force. 5.REASONING QUESTIONS 1.Why is it safer to be inside a car than standing under a tree during lightning? 6.DISTINGUISHING AND DIFFERENTIATING QUESTIONS 1.Distinguish between electric potential and potential difference. 2.Distinguish between conductors and insulators. 3.Distinguish between polar and non-polar molecules 4.State the differences between electric field intensity and electrical potential 7.THEORY QUESTIONS 1.What is meant by quantization of electrical charge? 2.What is permittivity and relative permittivity? How are they related. 3.What does an electric dipole experience when kept in a uniform electric field and non – uniform electric field.


4.Explain the working of microwave oven. 5.What is non polar molecule? Give examples. 6.What is polar molecule? Give examples. 7.What is the effect of placing a dielectric inside a parallel plate capacitor? 8.How can you increase the capacitance of a parallel plate capacitor. VI. THREE MARK PROBLEMS 1.A polythene piece rubbed with wool is found to have a negative charge of 3x10-7C .Calculate the number of electrons it has gained. 2.A glass rod rubbed with silk acquires a charge of + 8 x 10 -12. Find the number of electrons it has lost. 3.Two positive charges of 5C and 3C are kept at a distance of 3m from each other in vacuum. What is the force between them? 4.When two point charges +6c and -5C experiences a force of 2.7x1011 N. Find the distance between them. 5.Two point charges at a certain distance experiences a force of 5N . Each charge is doubled in magnitude and distance between the is halved. Calculate the new force . 6.Two spheres charged with equal but opposite charges 10 cm apart in a medium of relative permittivity 9 experiences a force of 103 N. Calculate charge on each sphere. 7.The electrostatic force between two point charges kept at a distance d apart, in a medium r =6, is 0.3N. Calculate the force between them at the same separation in vacuum. 8.The force of attraction between the two point charges increases from 5N to 50N when the dielectric medium is replaced by air. Find the relative permittivity. 9.Calculate the permittivity of a dielectric of dielectric constant 6. 10.Two point charges+10C and -10C are placed 5mm apart. Calculate the electric field at a point 5 cm from its centre along the equatorial line. 11.Two point charges+10C and -10C are placed 5cm apart.


Calculate the electric field at a point 10 cm from its centre along the axial line. 12.The potential at a point 50 cm from the centre of an electric dipole of dipole moment 10-5 C m is 1.8x105V. Find the angle made by the line joining the point and the centre of the dipole with the axis of the dipole. 13.The potential difference between two points 2.5 cm apart in an electric field is 10V. Find the electric field intensity between these points. 14.Calculate the potential at a point due to a charge of 100C at a distance of 9 m . 15. Calculate the amount of work done in bringing a charge of 2x10-9C from infinity to a point having potential of4x104V 16.An infinite charged plane sheet produces a field of 2x105 NC-1 at a distance of 5 cm. Find the surface charge density. 17.A uniformly charged conducting shell of 2 cm diameter has a surface charge density of 80C m-2.Find the charge on the shell. 18.A spherical shell of radius 2 cm has a charge of 4.5x10-12.Calculate the electric field at a point 3 cm from its centre. 19.Electric field intensity is 400Vm-1 at a distance of 2m from a point charge. At what distance it will be 100Vm-1. 20.Two point charges +4q and +q are placed 30 cm apart. At what point on the line joining them the electric field in zero? 21.Calculate the electric field intensity at a point 20 cm away from a point charge of 2x10-5C 22.Calculate the magnitude of the force acting on a charge of 2x10-10 C placed in a uniform electric field of 10Vm-1. 23.A charge experiences a force of 0.02N in an electric field of intensity 5x104 Vm-1. Find the value of the charge. 24.Two charges +2.5C and -2.5C are separated by a distance of 5 cm. Find the electric dipole moment 25.An electron experiences a force of 1.82x10-14N in an electric field . Calculate the acceleration produced on it. 26.An electric dipole with dipole moment 4x10-9C m is aligned at 300 with the direction of a uniform electric field of magnitude 5x104NC-1. Calculate the magnitude of the torque acting on the dipole.


27.A molecule having dipole moment 3.4x10-30C m is placed in an electric field of 2x104 N C-1.Calculate the maximum torque that can act on the molecule. 28.When a point charge of 6C is moved between two points in an electric field, the work done is 1.8x10-5J.Find the potential difference between the two points. 29.The work done in moving 4C charge from one point to another in an electric field is 0.012 J. Find the potential difference between them. 30.Calculate the potential energy of two equal negative point charges of magnitude 2C placed one metre apart in air. 31.A dipole of dipole moment 8x10-10 C m is inclined at an angle 600 with an electric field of 0.9x10-4 N C-1. Calculate its potential energy. 32.The equivalent capacitance of two capacitors in series is 1.5F. The capacitance of one of them is 4F. Find the value of capacitance of the other. 33.A capacitor of capacitance 6F is connected to a 100V battery. Calculate the energy stored in the capacitor. 34.The capacitance of a parallel plate capacitor increases from 5F to 50F when a dielectric is filled between the plates. Find the permittivity of the dielectric. 35.Three capacitors of capacitances 1F, 2F and 3F are connected in series. Find the effective capacitance of the capacitors. 36.Calculate the charge that can be stored in a 50F capacitor connected to a source of potential difference of 20 V. 37.Calculate the capacity of a parallel plate capacitor consisting of two circular plates of area 400cm2 and separated by a distance of 2mm with air as medium. 38.Calculate the capacity of a parallel plate capacitor consisting of two circular plates of area 80cm radius and separated by a distance of 1mm mica plate of dielectric constant 6 . 39.If a sphere surrounded by air is dipped in a liquid, its capacitance changes from 4 pF to 12 pF . What is the dielectric constant. 40.Three capacitors of capacitances 0.5F, 0.3F and 0.2F are connected in parallel . Find the effective capacitance of the


capacitors. 41.Calculate the work done in giving a charge of 8x10-18 C on a condenser of capacity 100F.

VII. FIVE MARK QUESTIONS. 1.State Coulomb’s law in electrostatics and State its vector form. 2.List the properties of electric lines of force. 3.Define electric field at a point. Give its unit and obtain an expression for the electric field at a point due to a point charge. 4.Derive an expression for the torque acting on the electric dipole when placed in a uniform field. 5.Derive an expression for electric potential energy of an electric dipole in an electric field. 6.Write a note on equipotential surface. 7.Explain the method of charging by induction. 8.Explain the distribution of charges on a conductor and action of point. 9.Derive an expression for electric field due to two parallel charged sheets. 10.Deduce an expression for the equivalent capacitance of capacitors connected in series. 11.Deduce an expression for the equivalent capacitance of capacitors connected in parallel. 12.Prove that the energy stored in a parallel plate capacitor is q2 /2C or 1/2 CV2 VIII.TEN MARK QUESTIONS 1.Derive an expression for electric field due to an electric dipole at a point on its axial line 2. Derive an expression for electric field due to an electric dipole at a point along the equatorial line . 3.Derive an expression for electric potential due to an electric dipole. Discuss the special cases. 4.State Gauss’s law. Applying this, calculate electric field due to (i) an infinitely long straight wire with uniform charge density (ii) an infinite plane sheet of charge of q. 5.Explain the principle of capacitor. Deduce an expression for the capacitance of the parallel plate capacitor.


6.What is dielectric? Explain the effect of introducing a dielectric slab between the plates of parallel plate capacitor. 7.State the principle and explain the constructions and working of Van de Graaff generator. 8.Determine electric field due to uniformly charged spherical shell at a point (i) out side the shell (ii) on the surface (iii) inside the shell.

KEY-LESSON-1

1 c 21 a 41 a 61 d 81 c 101 c 121 c 141 b 161 a 181 b 2 d 22 a 42 b 62 b 82 a 102 b 122 d 142 a 162 b 182 d 3 c 23 a 43 b 63 b 83 c 103 c 123 c 143 a 163 d 183 c 4 d 24 a 44 a 64 d 84 d 104 b 124 c 144 a 164 d 184 c 5 d 25 a 45 c 65 c 85 a 105 d 125 d 145 c 165 a 185 b 6 d 26 a 46 b 66 a 86 b 106 b 126 a 146 c 166 a 186 d 7 d 27 a 47 d 67 b 87 a 107 a 127 c 147 b 167 c 187 c 8 b 28 c 48 c 68 a 88 c 108 a 128 d 148 a 168 d 188 c 9 d 29 c 49 c 69 c 89 c 109 c 129 d 149 a 169 b 189 a


10 d 30 a 50 b 70 d 90 c 110 d 130 c 150 d 170 d 190 c 11 c 31 c 51 d 71 c 91 c 111 b 131 c 151 d 171 d 191 a 12 c 32 b 52 d 72 a 92 d 112 a 132 c 152 d 172 c 192 c 13 b 33 b 53 d 73 a 93 b 113 a 133 d 153 d 173 a 193 d 14 d 34 b 54 c 74 c 94 d 114 b 134 b 154 c 174 c 194 d 15 c 35 d 55 b 75 c 95 c 115 c 135 a 155 d 175 c 195 a 16 d 36 b 56 b 76 c 96 c 116 b 136 b 156 d 176 b 196 c 17 d 37 a 57 d 77 c 97 b 117 d 137 a 157 c 177 c 197 c 18 d 38 b 58 b 78 b 98 b 118 c 138 d 158 a 178 b 198 d 19 b 39 b 59 c 79 c 99 c 119 c 139 a 159 a 179 b 199 c 20 d 40 b 60 a 80 d 100 b 120 b 140 b 160 a 180 c 200 b

2.CURRENT ELECTRICITY.

1.Super conductors have zero a) resistance b) conductance c) permeability d) permittivity 2.The reciprocal of the slope of the graph drown between V&I for steady current in a conductor gives a) resistance b) conductance c) resistivity d) conductivity 3.The current always flows from a) +veto –ve b) –ve to +ve c) –ve to –ve d) +ve to +ve 4. The electrons always flows from a) +veto –ve b) –ve to +ve c) –ve to –ve d) +ve to +ve 5.A car battery has emf 12 volt and internal resistance 5x10 -2 .If it draws 60ampere current the terminal voltage of the battery will be a) 15V b) 3V c) 5V d) 9V 6.Resistance of a metal wire of length 10cm is 2. If the wire is stretched uniform to 50 cm the resistance is


a)25 b) 10 c )5 d) 50 7.The ratio of the resistance of conductor at 150C to resistance at temperature 37.50C is 4:5.What is the temperature co-efficient of resistance of the conductor. a) 1/75 b) 2/51 c) 2/75 d) 1/50 8.Ten identical wires (same material, same length and same cross section)each having a resistance of one ohm are joined in parallel ,the combination has a resistance of a) 10 b) 1 c) 0.1 d)0.01 9.Two wires of each length 1.3m and 2.6m which are having radius of 0.32mm and 0.16mm respectively made up of same material. The ratio of the resistances of wire is a) 8:1 b) 1:8 c) 1:4 d) 4:1 10.The potential developed between two ends of the conductor is 25V,2A current flows through it , the conductance of the conductor is a) 80 mho b) 80 milli mho c) 80 micro mho d) 40 mho 11.The resistance of the conducting wire is 10 , the resistance of another wire whose length is halved and the area is doubled made up of same material is a) 10 b) 40 c) 2.5 d)25 12.A charge of 60C passes through an electric lamp in 2 minutes .Then the current in the lamp is a) 30A b) 1A c) 0.5A d) 5A 13.A resistance of wire is cut into 4 equal parts and all the parts are connected in parallel. The ratio of the effective resistance to the original resistance is a) 2:1 b) 1:2 c) 1:4 d) 4:1 14.The end error in meter bridge can be eliminated by a) using thick copper strips b)interchanging two resistances in the gaps c) adjusting the balancing point near midpoint d) both (b) and (c) 15.Meter bridge is used to a) compare two resistances b) find specific resistance c) determine temperature coefficient d) all these 16.Actual resistance of standard 2 resistor is 2.1. The resistance to be connected to make it standard is a) 0.1 in series b) 42 in parallel c)0.1in parallel d)4.2 in series


17.Emf’s E1 and E2 of two given cells can be compared by using potentiometer with primary circuit of Emf E if a) E1 E2 b) E1, E2 E c)E1 E2 d) E1,E2 E 18.In a net work with constant source of emf , if more resistances are added in series , the power supplied by the source a) increases b) remains same c) decreases d) either increased or decreased 19.In a net work with constant source of emf , if more resistances are added in parallel , the power supplied by the source a) increases b) remains same c) decreases d) either increased or decreased 20.The emf of Lechlanche cell is 1.5V. When a resistance 5is connected, the current in the circuit is 0.25A, the internal resistance is a) 0.5 b) 1.5 c) 1.0 d) 2.0 21.In a potentiometer,the balancing point of a cell of emf 2.5V is 75 cm. By connecting another cell, if the balancing point is decreased by 15 cm , emf of the cell is a) 4V b) 3V c) 2V d) 1V 22.An incandescent lamp is operated at 250V.If the bulb is rated at 125W, its resistance must be a)1K b) 0.5K c) 2.0K d)2.5K 23.Two identical resistances are first connected in series and then in parallel to a source of emf 0.3V , the ratio of power supplied respectively is a) 4:1 b) 1:2 c) 1:4 d) 2:1 24.Total current of 3A is passed through the combination of two identical resistances are first connected in series and then in parallel, the ratio of power supplied respectively is a) 4:1 b) 1:2 c) 1:4 d) 2:1 25.Free electrons are very loosely attached to the a) nuclei b) protons c) atoms d) neutrons 26.Expression for electric resistance(R) is a) R=mL / nAe2 b) R=nL/ mAe2 c)R= nAe2/mL d)mLV/ nAe2 27.The conductivity of a material is obtained by the formula a) = RA/ l b) =lA/R c) = l /RA d) =A/R 28.Discontinuous change in specific heat of material occurs at


a) transition temperature b) high temperature c) 0K d) room temperature 29.If the resistance of a material increases with increase in temperature then its temperature coefficient of resistance is a) zero b) negative c) positive d) none of these. 30.Due to aging , the internal resistance of a cell a) increases b) decreases c) does not change d) becomes zero 31.The condition for bridge balance in Wheatstone’s bridge is a) P/S = R/Q b) PR = QS c) PS = QR d) PQ = RS 32.If a charge of 1C passes through an electrical equipment in 10 s , then the current flowing through is a) 0.5A b) 1A c) 0.1A d) 10A 33.The marking at the bottom of a tape recorder are as follows 9V,450mA. The net resistance of the system is a) 20 b) 200 c) 1/20 d) 2 34.An electrical instrument of resistance 30 is operated at 240V. The power is a) 240W b) 1290W c) 920W d) 1920W 35.The number of electrons flowing per second through a conductor , when a current of 3.2A flows through it is a) 2x1019 b) 3x1018 c) 6.25x1018 d) 6.25x1019 36.A 1.15 KW , 230V water heater can draw a current a) 0.2A b) 2A c) 5A d) 0.5A 37.If charge per unit volume of a conductor is 600C and the current density is 1.2Am-2 , then the drift velocity of the electrons is a) 0.2x10-2 m/s b) 7.2x10-3m/s c) 200 m/s d) 5x10-3 m/s 38.Three resistances of values 10, 2 and 3 are connected to form the sides of a triangle AB,BC and CA respectively . The effective resistance between A and B is a) 3.33 b) 2.33 c) 3.5 d) 3.9 39.A cell of emf 9V and internal resistance 1 is connected to an external resistance of 8, the potential difference across the cell is a) 9V b) 1V c)6V d) 8V 40.In Wheatstone’s bridge , under bridge balance condition the four resistances of the four arms in cyclic order is


a) 5,10,4,8 b) 5,10,8,4 c) 5,8,10,4 d) 5,4,8,10 41.The drift velocity does not depend upon a)the magnetic field b) the mass of the electron c)the charge of the electron d)the relaxation time 42.When the diameter of a conductor is doubled , its resistance a) decreases twice b) decreases four times c) decreases sixteen times d) increases four times 43.A cell of emf 2.2V sends a current of 0.2A through a resistance 10. The internal resistance of the cell is a) 0.1 b) 1 c) 2 d) 1.33 44.The electrical resistivity of a thin copper wire and a thick copper rod are respectively 1m and 2 m . Then a) 1 2 b) 2 1 c) 1 = 2 d) 2/1= 45.The brown ring at one end of a carbon resistor indicates a tolerance of a) 1 % b) 2 % c) 5 % d) 10 % 46.Length of the wire with resistance ‘R’ is stretched for 3 times of its original length , now the resistance becomes a) 3R b) 1.5R c) 3R2 d) 9R 47.As the temperature increases , the conductance of a conductor a) increases b) decreases c) does not change d) becomes infinity 48.The ratio of the effective resistance of two 2 resistance when they are connected in parallel and in series a) 1:4 b) 4:1 c) 1:2 d) 2:1 49.Mobility is proportional to a) inversely to the electric field b) directly to the mass of the electron c) inversely to the drift velocity d) inversely to the charge 50.The amount of current flowing through a conductor is directly proportional to a) the number of electron per unit volume b) the drift velocity d) the cross sectional area of the conductor d) all the above 51.The magnets used to levitate the trains from the rails a) permanent electromagnets b) strong magnetic substance


c) a magnetic field with varying frequency d) super conducting magnets 52.The special features of carbon resistor a) small in size b) stable c) cheaper d) all these 53.The specific resistance of a conductor is 5x10-5 m . If its length is elongated 4 times then its specific resistance is a) 20x10-5 m b) 1.25x10-5 m c) 5x10-5 m d) 8x10-4 m 54.A conductor of length 2 m and area of cross section 6 mm2 has specific resistance 3x10-6 m . Then its resistance is a) 4 b) 1 c) 0.1 d) 0.9 55.A circuit consists of two resistances R1& R2 connected parallel to each other. When a current I flows through the circuit , then the amount of current flowing through R1 is a) I1= I(R2/ R1+R2 ) b) I1= I(R1/ R1+R2 ) c) I1= IR2/ R1-R2 ) d) I1= I(R1/ R1+R2) 56.The resistivity of a conductor is 40x10-6m . Then its conductivity is a)25x105mhom-1 b)2.5x104mhom-1c)25x10-5mhom-1 d)25x10-4mhom-1 57.Electrolytes are a) the liquids which allow the ions to move through them b) the liquids wherein charged ions can be dissociate in opposite direction c) both (a) , (b) are correct d) (a) is correct, (b ) is wrong 58. The cells from which the electric energy is derived by irreversible chemical reactions are a) primary cell b)secondary cell c)Daniel and dry cell d)both(a)& (c) 59.According to Faraday’s laws of electrolysis , when charge is passing through the electrolyte , the mass of the substance liberated at the electrode depends on a) current b) charge c) time d) all these 60.Current is a) the number of electrons crossing per second at a point in a conductor b) rate of flow of chargec) a scalar quantity d) all the above 61.The direction of conventional current is the direction a) of motion of electrons b) opposite to the motion of positive charge c)of random motion of electrons d)opposite to the motion of electrons 62.In a carbon resistor it consists of yellow, yellow and black rings at


one end and silver ring at the other end, then the resistance is a)44000+10 % b) 440 +10 % c) 44 +10 % d) 4400 +10 % 63.The appropriate material to be used in the construction of resistance boxes out of the following is a) copper b) iron c) manganin d) aluminium 64.When two resistances connected in series and parallel their effective resistances are 12 and 8/3 then the individual resistances are a) 6, 6 b) 3 , 9 c) 7 , 5 d) 8 , 4 65.The resistance of a wire of length is 6 . If its length is elongated as 2L, then its resistance is a) 6 b) 12 c) 24 d) 48 66.In a Wheatstone bridge P=15 , Q= 35 , R=60, then S=? a) 80 b) 85 c) 105 d) 140 67.When 1.6 A current is flowing through a conductor in one minute, then the number of electrons moving in it is a) 60x1019 b) 3x1020 c) 6.25x1018 d) 1.6x10-19 68.Two wires of equal length are having the radius ratio 1:2, then the ratio of their resistances is a) 1:4 b) 4:1 c) 1:2 d) 2:1 69.When 400mA current flowing through a wire of resistance 25, then the potential difference between the ends of the wire is a) 5V b) 1V c) 10V d) 12.5V 70.The substance which have negative temperature coefficient of resistance a) carbon b) ebonite c) Germanium d) all the above 71.A cell having emf 1.5V is connected with a resistor of 1000. What is its power? a) 2.25 mW b) 1.5W c) 225W d) 150mW 72.The substances like carbon and ebonite are a)having negative temperature coefficient of resistance b) conducting materials c) electrolytes d) having low temperature coefficient of resistance 73.The relation between current density and drift velocity a) J=neA/ Vd b) Vd=Jne /A c) Vd = J / ne d) J = Vd e /A


74.When the length of a conductor is cut into two equal parts , one of its resistance is …… and its resistivity is …… a) halved; halved b) halved; increased twice c) increased twice ; halved d) halved ; having no change 75.The flow of free electrons by emf in a definite direction produces a) current b) resistance c) drift velocity of electron d) all the above 76.In the case of carbon, when temperature increases the resistance a) increases b) decreases c) remains the same d) becomes zero 77.An electric bulb shows 550 resistance when a potential of 220 V is applied to it.The amount of current flowing through it is a) 0.5 A b)2.5 A c) 0.4 A d) 5A 78.Ohm's law is true for a) metals only b) semiconductors only c) both for metals and semiconductors d) neither metals nor semiconductors 79.In a Wheatstone's network if the cell and galvanometer are inter changed a) the condition for null deflection remains same as before interchanging b) null deflection can never be obtained c) the condition for null deflection will be disturbed d) the current in all branches becomes zero 80.Current in super conducting wire can flow a) with change in magnitude b) with change in direction c) without change in magnitude and direction d) with change in magnitude and direction 81.The effective resistance of two resistance connected in parallel is 2.4If the second resistance is 1.5 times the first one, the resistances are a) 4 and 6 b ) 2 and 3 c)3 and 4.5

d) 6 and 9 82. If the balancing point lies at the centre of the meter bridge wire and the resistance in the resistance box is 5 , then the unknown resistance is a) 5 b) 10 c) 2.5 d) 0 83.The value of resistance having code brown, red and orange is a) 12K b 120 c) 1.2 K d) 12


84.Metre bridge consists of a wire of high a) temperature coefficient and low specific resistance b) low temperature coefficient and high resistance c)low specific resistance and hgih temperature coefficient d) high specific resistance and low temperature coefficient 85.Ohm's law is valid when ............. is constant a) voltage b) temperature c) resistance d) area 86.The power generated in a resistor of 5kwith a current flow of 50 mA is a) 12.5W b) 250W c) 1.25MW d) 2.5 MV 87.The drift velocity of electrons having a charge of 12.8x109C and current density of 2x106 A/m2 is a) 1.56 m/s b)��15.6x10-5m/s c) 156x10-5 m/s d) 0 88.Resistance of a material at 00C and 300C are respectively 40 and 90. Its temperature coefficient of resistance is a) 0.4617 /0C b) 0.04617 /0C c) 0.005 /0C d)24 /0C 89.The resistance of a conductor of unit length having unit area of cross section is a) resistivity b) conductivity c) conductance d) capacitance 90.Two copper wire of length 1m and 9m have equal resistances. Then their diameters are in the ratio of a) 3:1 b) 9:1 c) 1:9 d)1:3 91.Resistivity of mercury is zero at a) 2.4 K b) 4.20C c) 4.2 K d) 2.4 0 C 92.A material with negative temperature coefficient of resistance is called a) metal b) alloy c) thermistor d) thermometer 93.What is the minimum number of bulbs each marked60 W, 40 V , that can work safely when connected in series with a 240 V main supply? a) 2 b) 4 c) 6 d) 8 94.In secondary cells the process of reproducing active materials is called a) charging b)discharging c) specific gravity d) internal resistance 95.Discontinuous change in specific heat of a material occurs at a) transition temperature b) high temperature c)room temperature d) 0 K


96.If two resistors of resistance 200 and 0.1k are connected in series then the effective resistance of the system is a) 200.1 b) 300 c) 201 d) 2.1 k 97.The system may be used to launch satellites directly into orbit from earth , without the use of rockets is a) solid propellant system b) liquid propellant system c) super conducting magnetic propulsion system d) electric propellant system 98. If the internal resistance of the electric cell increases, the delivered electric current a)decreases b)increases c)first increases and then decreases d) zero 99.If charge per unit volume of a conductor is 6mC and the current density is 1.2Am-2 , then the drift velocity of the electron is a) 0.2x10-3m/s b) 7.2x10-3m/s c) 200 m/s d) 5x10-3m/s 100.The resistance of a conductor is 5 at 500C and 6 at 1000C . Then the resistance at 00C is a) 0 b) 3.5 c) 4 d) 8 101.The value of electrical energy equal to 1KWhr is a) 1 unit b) 1 joule c) 1 volt d) 1 ampere 102.In a metre bridge , with a standard resistance of 5 ohm in the right gap, the ratio of balancing length is 3:2. The value of the other resistance is a) 10/3 b) 10 c)15/2 d) 3/5 103.The balancing lengths of two cells are 250 cm and 750 cm respectively , in a potentiometer experiment. If the emf of the first cell is 2 V , the emf of the second cell is a) 6V b) 4V c) 2/3 V d) 3/2 V 104.A 750W power iron box is used for 4 hours. If the cost per unit is 75 paise, the total expense is a) Rs.22.50 b) Rs.5.25 c) Rs2.25 d) Rs3.00 105.For what time a current of 1.5A pass through a copper-voltameter to deposit 1g of copper?(Z=3.3x10-4 g/C) a) 25minute b) 50 minute c) 34minute d) 40 minute 106.Silver and zinc voltmeters are connected in series and same current is passed through both of them for same time. If x kg of Ag is


liberated, then amount of Zn liberated in kg will be very near to (chemical equivalent of Zn = 33;chemical equivalent of Ag=108) a) x b)x/5 c) x/3 d) x/2 107.If J is the current density then the power transferred per unit volume in joule in a resistor of resistivity is a) J2/ b) J2 c) J d) J22 108.In hydrogen atom, electron moves in an orbit of 0.5A0 with a speed of 2.2x106 m/s. What is equivalent current? a) 1.25A b) 1.12A c)1.12mA d)1.12pA 109.The resistance of wire is R ohm. What will be new resistance ,if it is stretched uniformly n times its original length a) nR b) R/n c) n2R d) R/n2 110.If R1 and R2 be the resistances of the filaments of 200W and 100W electric bulbs operating on 220V, then a) R1=R2 b) R1=2R2 c) R2=2R1 d) there is no relation between R1and R2 111.A voltmeter 100V range is of 9000 ohm resistance and another voltmeter of range 80v has a resistance of 11000 ohm. This combination is connected across 120v. The reading of voltmeter of 100v range will be a) 54V b) 44 V c) 66V d) 56V 112.The ratio of resistance to conductance is a) 1:R b) R:1 c) 1:R2 d) R2:1 113.The ratio of conductance to resistance is a) 1:R b) R:1 c) 1:R2 d) R2:1 114.The ratio of resistivity to conductivity is a) 1: b) :1 c) 1: 2 d) 2 :1 115.The temperature coefficient of resistance is positive for a) aluminium b) carbon c) germanium d) none of the above 116.Which one of the following is the best material for making connecting wires? a) manganin b) constantan c) copper d) nichrome 117.Which one of the following is the best material for making standard resistance wire? a) tungsten b) constantan c) copper d) iron


118.A primary cell and a secondary cell have the same emf .Which of these will provide higher value of the maximum current that can be drawn? a) primary cell b) secondary cell d) both primary cell and secondary cell d) none of these 119.A wire has a resistance of 10 ohm. If it is stretched by one tenth of its original length , then its resistance will be a) 10 ohm b) 12.1 ohm c) 9 ohm d) 11 ohm 120.A wire has a resistance of 10 ohm. A second wire of the same material having length double and radius of cross-section half that of the first wire is there. The resistance of the second wire. a) 20 ohm b) 40 ohm c) 80 ohm d) 10 ohm. 121.The resistance of a wire is R1 ohm. The wire is stretched to double its length the resistance become R2. Now, the ratio of R1 and R2 is a) 1:1 b) 1:2 c) 1:4 d)4:1 122.The resistance of a wire is R1 ohm. The wire is stretched to double its length the resistance become R2. Now, the ratio of their resistivity is a) 1:1 b) 1:2 c) 1:4 d)4:1 123.Three resistances R1 , R2 and R3 are connected in parallel. The resultant resistance R is a) less than any of the three resistances b) equal to sum of the three resistances c) greater than the sum of the three resistances d) none of the above 124.The specific resistance of the material of the wire depends on the a) area of cross-section b) length c) mass d) none of the above 125.Two unequal resistances are connected in parallel in a circuit . Which one of the following statements is correct? a) the current is same in both the resistances b) the smaller resistance has the smaller conductance c)a large current flows through the larger resistance d) the voltage drop across both the resistances is same 126.The difference of potential between the terminals of a cell in an open circuit is called a) emf b) resistance c) capacitance d) potential difference


127.The difference of potential between the terminals of a cell in an closed circuit is called a) emf b) resistance c) capacitance d) potential difference 128. ‘ n’ similar resistors each of resistance ‘r’ when connected in parallel has the total resistance R. When these resistances are connected in series , the total resistance will be a) n2R b) nR c) R/n d) R/n2 129.Ten identical resistances each having a resistance of 1 are joined in parallel. Then combination has the resistance has the resistance of a) 10 b) 1 c) 0.1 d) 0.01 130.In a Wheatstone bridge the resistances in the ratio arms are 100 and 150 respectively. If R=80 , the resistance of the fourth arm will be a) 120 b) 80 c) 150 d) 70 131.A wire has resistance 12 ohm. It is bent in the form of a circle .The effective resistance between the two points on any diameter of the circle is a) 12 b) 24 c) 6 d)3 132.In Wheatstone’s bridge ,P=9, Q=11 , R=4 and S= 6. How much resistance must be put in parallel to the resistance S to balance the bridge? a) 24 b) 44/9 c) 26.4 d) 18.7 133.These are behaving like thermistor. a) insulators and conductors b) semiconductors and conductors c) conductors and alloys d) insulators and semiconductors 134.When three resistors are connected in series then the value of the effective resistance is a) less than the individual resistance b) greater than the individual resistance c)greater than or equal to individual resistance d)less than or equal to individual resistance 135.In the case of Wheatstone’s bridge , the bridge balance condition will be obtained only when a) the current through the galvanometer is maximum b) the current through the galvanometer is minimum


c) the current through the galvanometer is zero d) the current through the galvanometer is infinity 136.If 0.2 is the resistance per unit length of the wire, then the resistance of the Metre bridge wire is a) 2 b) 200 c) 0.2 d) 20 137.The mass of substance liberated during electrolysis is 0.6 g when 4A of current flow for 2 minute. The chemical equivalent of the substance is a) 2.5x10-6kg C-1 b) 1.75x10-6kg C-1 c) 1.5x10-6kg C-1 d) 1.25x10-6kg C-1 138.The graph between voltage and current for ohmic conductors is a) curve b) straight line b) parabola d) ellipse 139.If a wire of resistivity is stretched to double its length , then its new resistivity will a) be half b) be double c) be four times d) not change 140.As the temperature increases, resistivity of metals a) remains constant b) decreases b)increases d) becomes zero 141. As the temperature decreases, resistivity of materials a) increases b) increases and decreases c) decreases d) remains constant 142.Which of the following is an identical pair? a) germanium, silicon b) silver, wood c) aluminium, constantan d) backelite, iron 143.At the critical temperature the resistance of a superconductor a) increases rapidly b) decreases rapidly c) remains constant d) increases slowly 144.Abird sitting on an insulated wire carrying a current feels quite safe because a) the bird is a non-conductor of electricity b) resistance of the bird is very large c) there is a large potential difference between bird and wire d) there is no potential difference between bird and wire 145.Resistivity and resistance of superconductors is a) low, high b) zero, infinity c) zero , zero d)large , very large


146.Which term is not connected with a Voltaic cell? a) copper electrodes b) spongy lead c) zinc electrode d) dilute sulphuric acid 147.In primary cells electric energy is derived by a) reversible chemical reactions b) isothermal process c) irreversible chemical reactions d) adiabatic process 148.The specific resistance of wire depends on a) its radius b) its length c) the material of the wire d) the shape of the wire 149.The resistance of a a) thick conductor is less than that of a thin conductor b) thin conductor is less than that of a thick conductor c) short conductor is more than that of a long conductor d) both (a) and ( c) 150.The current flowing through a conductor is a) directly proportional to drift velocity b) inversely proportional to drift velocity c) numerically equal to drift velocity d) independent of drift velocity 151.If the radius of the conducting wire is doubled its resistivity a) is doubled b) remains the same c) is halved d) is four time is initial value 152.The drift velocity acquired by unit electric field is called a) conductivity b) resistitivity c) mobility d) conductance 153.The drift velocity does not depend upon a) magnetic field b) mass of the electron c) charge of the electron d) relaxation time 154.Charging is the process of reproducing a) current b) voltage c) power d) active material 155.A wire of resistance R is divided into 10 equal parts. These parts are connected in parallel, the equivalent resistance of such connection will be a) 0.01R b) 0.1R c) 10R d) 100R 156.Wheatstone bridge is used to measure


a) emf b) resistance c) current d) inductance 157.Manganin wire used in metre bridge and potentiometer has a) zero resistivity b) high resisitivity c) low temperature coefficient of resistance d) high temperature of resistance 158.The length and area of cross section of a conductor are doubled its resistance will be a) halved b) unchanged c) doubled d) increases four times 159.The direction of current and the direction of electrons are always a) equal b) same c) opposite d) parallel 160.The net charge stored at any junction is equal to a) zero b) maximum c)negative d)positive 161.If a steady current is flowing through the potentiometer wire, then the potential difference across any length is a) directly proportional to square of the length b) inversely proportional to square of the length c) inversely proportional to the length d) directly proportional to the length 162.Thick copper strips, which is used in metre bridge have a) low temperature coefficient b) high temperature coefficient c) high resistance d) low resistance 163.The high resistance which is connected in the secondary circuit of a potentiometer allows a) high current through the galvanometer b) low current through the galvanometer c) zero current through the galvanometer d) negative current through the galvanometer 164.The positive ions which are mostly formed from metals or hydrogen are called a) anions b) cations c) positive particles d) atoms 165.The emf of a cell is always a) less than its potential b) greater than its potential c) equal to its potential d) equal to negative 166.The emf is a) directly proportional to the resistance in the external circuit


b) inversely proportional to the resistance in the external circuit c) independent of the resistance in the external circuit d)is a force 167.The resistance offered to electric flow by a conductor of unit length and unit area is known as a) electrical resistivity b) electrical conductivity c) electrical permittivity d) electrical mobility 168.The conductivity of a conductor defends on the _____ of the conductor a) length b) material c) resistance d) area of crass section 169. The direction of conventional current is a) the direction in which the negative charges flow b) the direction in which the positive charges flow c) opposite to the direction in which the positive charges flow d) independent of the direction of both positive and negative charges low 170.The electrical resistivity of a conductor is a)directly proportional to its length b) inversely proportional to its area c) inversely proportional to its d) a constant to a given conductor 171.The term mobility is given by a) = Ee / m b) = e / E c) = e / m d) = Ee / 172.Electromotive force is a) the force required to move electrons b) the force required to move electrons in all directions c) the force required to move electrons in a particular direction d) the work done in moving a unit charge from one end to the other of a conductor 173.One kilowatt hour is equal to a)36x106 J b) 3.6x106 J c) 3.6x105 J d) 36x103 J 174.The potential difference between two ends of a wire carrying 2A current is 4V .The power is a) 8 W b) 6 W c) 2 W d) 4 W 175.In a watt meter , the deflection of the pointer produced by the current flow is


a) directly proportional to the power b) inversely proportional to the power c) directly proportional to the resistance d) inversely proportional to the resistance 176.A current of 5 A flows through a coil of resistance 0.5 ohm. Then power generated is a) 2.5 W b) 10 W c) 12.5 W d) 25 W 177.According to Faraday’s law of electrolysis , when a current is passed , the mass of ions deposited at the cathode is independent of a) current b) charge c) time d) resistance 178.A carbon resistance reads Red-Red-Black. What is its resistance? a) 2.2 b) 22 c) 220 d) 22K 179.The internal resistance of a freshly prepared cell is a) zero b) high c) very high d) low 180.Due to ageing , the internal resistance of a cell a) remains constant b) decreases c) increases d) becomes zero 181.Which of these is not a feature of Daniel cell? a) copper vessel b) zinc rod c) 1.08V d) 1.5V 182.Which of these is not a primary cell? a) Daniel cell b) Lithium button cell c) Lechlanche cell d) dry cell 183. Which of these is not a feature of Lechlanche cell? a)carbon rod, zinc rod b) zinc chloride c) ammonium chloride d) 1.5V,0.25A 184.The emf produced in a Lechlanche cell is about a) 1.08V b) 2.2V c) 2V d) 1.5V 185.A Lechlanche cell can supply a current of a) 0.1 A b) 0.25A c) 2.2 A d) 1.5 A 186.During charging and discharging the specific gravity of lead acid accumulator should lie between a) 1.28-1.2 b) 1.9 – 1.28 c) 1.28 – 1.12 d)1.8 -1.2 187.When 1 C of charge is allowed to flow through the electrolyte , the mass of ions deposited is equal to a) electro chemical equivalent b)equivalent weight of the substance c) atomic weight of the substance d) mass of 10000 atoms of silver 188.There are three resistances 2,3 and 5 connected in parallel to a battery of 10 V and of negligible resistance. The potential drop across 3 resistance is


a) 2V b) 5V c) 3V d) 10V 189.The sequence of bands on carbon resistor is brown, black, black and gold. The value of resistance is either a) 40 or 50 b) 105 or 95 c) 75 or 85 d) 145 or 155 190.A 50V battery is connected across a 10ohm resistor . The current is 4.5 A .The internal resistance of the battery is a) zero b) 0.5 c) 1.1 d) 5 191.The smallest resistance which can be obtained with ten 0.1 ohm resistor is a) 1 ohm b) 0.1 ohm c) 0.01 ohm d) 0.001 ohm 192.We have ‘n’ resistors each of resistance R. The ratio of the combination for maximum and minimum value is a) n b) n2 c) n3 d) 1/n 193.The resistance of two conductors in series is 40 and this becomes 7.5 in parallel . The resistances are a) 20 , 20 b) 30 , 10 c) 15 , 25 d) 18, 22 194.In the case of lead accumulator each plate is converted to a) Pb during discharge b) PbO2during discharge c) PbSO4 during discharge d) PbO during discharge 195.Three cells each of emf 1.5V and internal resistance 1 are connected in parallel. Then the emf combination is a) 1.5V b) 5V c) 4.5V d) 3V 196.The resistances in left and right gaps of a metre bridge are 4 and 6. The balance point is obtained at a) 20 cm b) 40 cm c) 30 cm d)25 cm 197.Three resistances each of 2 are connected to form a triangle .The resistance between any two terminals is a) 6 b) 1 c) 4/3 d) 4 198.The temperature coefficient of resistance of alloys is usually a) more than pure metals b) less than pure metals c) equal to pure metals d) nothing can be said 199.The length of two copper wires are in the ratio 4:2. If their diameters are in the ratio 2:4 then the ratio of their resistances is a) 8:1 b)16:1 c) 4:1: d) 1:4 200.A current of 4A flows through a resistance of 30 . The power


consumed is a) 240W b) 480W c) 360W d)120W II. IMPORTANT UNITS 1.The unit of electric current is ………. 2.The unit of drift velocity is ………. 3.The unit of mobility is ……… 4.The unit of electric current density is ………. 5.The unit of resistance is ………. 6.The unit of conductance is ………. 7.The unit of specific resistance or resistivity is ……… 8.The unit of conductivity is ………. 9.The unit of temperature of coefficient of resistance is ………. 10.The unit of internal resistance is ………. 11.The unit of electrical energy is ..……. 12.The unit of electrical power is ……… 13.The practical unit of electrical energy is ……….. 14.The unit of electrochemical equivalent is ………. III. STANDARD VALUES 1.The drift velocity of the electrons is of the order of ………. 2.The resistivity of metals and alloys are of the order of ………. 3.The resistivity of insulators is of the order of ………. 4.The resistivity of semiconductors is of the order of ………… 5.Mercury becomes a superconductor at………. 6. The tolerance of silver ring is …….. 7. The tolerance of gold ring is ……… 8. The tolerance of red ring is ………. 9. The tolerance of brown ring is …….. 10.The absence of any coloured ring at the end of resistor , corresponds to

tolerance level of … 11.One kilowatt hour is equal to ……… 12.The emf of voltic cell is ………. 13.The emf of lead-acid cell is ………. 14.The emf of Daniel cell is ……….. 15.The emf of Leclanche cell is about ……… 16.Leclanche cell can supply a current of ……….. 17.The specific gravity of the lead - acid accumulator is ……..


18.The specific gravity of the electrolyte in secondary cells, while accumulator is charging and discharging should lie between……

IV. IMPORTANT FORMULAE 1.Current flowing through a wire is ………. 2.Acceleration of electron in current flow is ………. 3. The drift velocity of an electron is ………. 4.The relation between current and drift velocity is ……… 5. The mobility of a charges is …….. 6.The current density is ………. 7.Potential difference between the two point by Ohm’s law is ……… 8.Resistance of a conductor is ……… 9.Electrical resistivity (specific resistance ) is ……….. 10.Conductance of a conductor is ……… 11.Conductivity of a conductor is ……… 12.Condition to balance Wheatstone’s network is ……… 13.Unknown resistance by metre bridge experiment is ………. 14.Temperature coefficient of resistance is ………… 15.The internal resistance of a cell is ………… 16.Emf of a cell connected in the secondary circuit of a potentiometer is 17.The effective resistance connected in series is …….. 18.The effective resistance connected in parallel is …….. 19.Ratio between the emfs of two cell is ……… 20.Electric power is ……… 21.Eletrical energy is ……. 22.Mass of the substance liberated during electrolysis is …….. 23.The electrochemical equivalent is ………. V.THREE MARK QUESTIONS I. DEFINITIONS: 1. Define electric current. 2. Define current density. 3. Define mobility. 4. Define electrical resistivity of a material.( specific resistance)


5. Define conductance. 6. Define conductivity, 7. Define temperature coefficient of resistance. 8. Define emf. 9. Define drift velocity. 10. Define Resistance. 11. Define electric power. 12. Define electrochemical equivalent of a substance. 13. Define superconductivity. 14. Define Transition temperature. 15. Define the effective resistance of the resistors connected parallel. 16. Define the effective resistance of the resistors connected series. 17. Define charging and discharging. 18. Define internal resistance. 19. Define electrolysis. II. LAWS AND PRINCIPLES 20. State Ohm’s law. 21. State Kichoff’s laws. 22. StateFaraday’s laws of electrolysis. III.USES.(APPLICATIONS) 23. List any three applications of superconductors. 24. State the uses of secondary cells. 25. State the use of Watt meter. IV. ADVANTAGES, DISADVANTAGES (LIMITATIONS) DRAW BACKS. 26. What are the merits of secondary cell? V.REASONING QUESTIONS 27. Why is copper wire not suitable for a potentiometer?


28. Why automobile batteries have low internal resistance? 29. Is emf a force? Explain. VI.DISTINGUISHING AND DIFFERENTIATING QUESTIONS 30. Distinguish between drift velocity and mobility. 31. Distinguish between electric power and electric energy. 32. Distinguish between emf and potential difference. 33. Distinguish between primary and secondary cells. VII.THEORY QUESTIONS 34. Name the three changes observed at the transition temperature. 35. The colour of carbon resistor is orange, orange, orange. What is the value of resistor. 36. What is the carbon resistor ? State the merits of them. 37. What is Thermistor? 38. Explain the function of Wattmeter. VI. THREE MARK PROBLEMS 1.Calculate the number of electrons constitute current of one ampere. 2.How many electrons will be there in 5A current? 3.6.25x1018 electrons flow through a conductor in 5 second . Then calculate the current in the circuit. 4.Calculate the time taken by 1019 electrons to flow through a point , so that the current is 0.8A. 5.A copper wire of 1mm2 area of cross section carries a current of 3A . Calculate the current density. 6.The average time between two successive collisions of an electron is 3.64x10-8s. Find its mobility. 7.The drift velocity of an electric field of 2x104Vm-1 is 10-3ms-1. Find drift velocity. 8.The potential difference between two plates by a distance of 25 cm is 200V. Calculate the electric field between them.


9.A metal wire of current density 3.2x107Am-2 has 1028 electrons per cubic metre . Find the average drift velocity. 10.A copper conductor of one metre long and 1 m2 area of cross-section has 3.5x106 free electrons . The drift velocity of the electrons is 3.5x106ms-1 . Calculate the current flowing through the conductor if the charge on an electron is 1.6x10-19C . 11.Current through a coil is 20mA when the potential difference cross it is 50V. Calculate the resistance of the coil. 12.Calculate the voltage across the resistance of 10 ohm if 2A current flows through it. 13.A 2V cell is connected across a load of 100 ohm. Calculate the current and power supplied by it. 14.Two resistances of a given material have the same area of cross- section if their lengths are 60 cm and 80 cm respectively. Then find the ratio of the resistances. 15.Two resistances of a given material , having the same lengths and in the ratio 3:2.If the area of cross-section of the first wire is 10-6 m2 , find the area of cross-section of the second wire. 16.The resistance of a conducting wire of length 2.2m and diameter 0.14mm is 30 ohm. Calculate its resistivity. 17.Resistane of a metal wire of length 10 cm is 2 ohm. Find the new resistance if the wire is stretched to 40 cm. 18.Three resistances 2,4 and 6 are connected in series. Find their effective resistance. 19.Four resistances each5 are connected in series. Find the effective resistance . 20. The temperature coefficient of resistance of a wire is 0.003/0C.If its resistance at 00C is 6, find its resistance at 600C. 21.The resistance of a wire at 00C is 6. If its resistance at 500C is 7.5, find the temperature coefficient of resistance of the wire . 22.The resistance of a conductor is 5at 500C and 6 at 1000C, then find the resistance at 00C. 23.An unknown resistance P is connected in the left gap of a metre bridge and a standard resistance 3 in the right gap. If the galvanometer shows zero deflection when the jockey is pressed at a


point 40cm from A , find the value of P. 24.A 10resistance is connected in series with a cell of 5.1V. A voltmeter connected in parallel to cell reads 5V.Calculate the internal resistance of the cell. 25.A cell of emf 2 V sends a current of 0.5A through a resistance of 3. Find the internal resistance of the cell. 26.In a potentiometer a cell of emf 1.5V balances at a length of 270 cm . If another cell balances at 360 cm for the same current what will be its emf? 27.The balancing lengths of two cells when compared using a potentiometer is 450 cm and 600 cm. find the ratio of the emfs of the two cells. 28.A bulb is labeled as 250V,100W.What is the resistance of the filament of the bulb in ohm? 29.When a current of 5A flows through a conductor of resistance 3, find the loss of power due to Joule heating effect. 30.An electric iron of resistance 40 is operated at 200V for one hour. Calculate the electric energy consumed. 31.A small heating element made of nichrome resistor connected to a 30V d.c. supply draws a current of 10A.Calculte the heat produced in 2 hour. 32.A current of 4A flows through a 12 resistor. Find the rate at which heat energy is produced in the resistor. 33.In an electroplating experiment m gram of silver is deposited when 4A of current flows for 2 minute. Calculate the amount of silver deposited by 6A of current for 40s. 34.The electrochemical equivalent of chromium is 1.8x10-7

kg C-1. Calculate the mass of chromium deposited if 2A current flows for 30 minute. 35.Currents of 2A and 5A flow respectively for 30 minute through a copper voltmeter. Find t he ratio of the mass of the substances liberated. 36.The chemical equivalent of hydrogen and aluminium are 1 and 9 respectively. If mass of aluminium liberated when 1A current flows for one hour is 1.5 gram, find the mass of hydrogen liberated when same current flows for the same time.


37.One ampere current flows for one minute through a silver voltameter. If 0.067 gram of silver is deposited on the cathode ,find the electro chemical equivalent of silver. 38.A current of 2A flows through a silver voltameter. If the mass of silver deposited in 30 minute is 2.41gram. Calculate the mass of silver deposited in 1 hour. 39.Resistance of a metal wire of length 10 cm is 2. If the wire is stretched uniformly to 50 cm, find the new resistance. 40.The colour code on a carbon resistor is red-red-black. Find the resistance of the resistor. VII.SHORT ANSWER (5 MARK QUESTIONS) 1.Distinguish between drift velocity and mobility. Establish a relation

between drift velocity and current. 2.Explain the determination of internal resistance of a cell using voltmeter. 3.Derive an expression for the effective resistance of a series of resistors with

a neat diagram 4. Derive an expression for the effective resistance of resistors in parallel

with a neat diagram. 5.What are the applications of super conductors? 6.Explain the principle of potentiometer with a neat sketch. 7.State and explain Kirchoff’s laws of electrical network. 8.Describe an expression to find unknown resistance and temperature of coefficient of resistance using meter bridge. 9.Define the term specific resistance . How will you find this using a metre bridge? 10.How can emf of two cells be compared using potentiometer? 11.Obtain the conditions for zero deflection in the Wheatstone’s network. 13.State and explain Faraday’s first law of electrolysis. 14. State and explain Faraday’s second law of electrolysis 15.With the help of a neat diagram describe Daniel cell and explain the reactions taking place in it. 16.Describe Leclanche cell with the help of a diagram 17.Explain the construction and action of the lead acid accumulator.


… … … … & … … … …

KEY- 2 LESSON

1 a 21 c 41 a 61 d 81 a 101 a 121 a 141 c 161 d 181 d 2 a 22 b 42 b 62 c 82 a 102 c 122 a 142 a 162 d 182 b 3 a 23 c 43 b 63 c 83 a 103 a 123 a 143 b 163 b 183 b 4 b 24 a 44 c 64 d 84 d 104 c 124 d 144 d 164 b 184 d 5 d 25 a 45 a 65 c 85 b 105 c 125 d 145 c 165 b 185 b 6 d 26 a 46 d 66 d 86 a 106 c 126 a 146 b 166 c 186 c 7 a 27 c 47 b 67 a 87 b 107 b 127 d 147 c 167 a 187 a 8 c 28 a 48 a 68 b 88 b 108 c 128 a 148 c 168 b 188 d 9 b 29 c 49 a 69 c 89 a 109 c 129 a 149 a 169 b 189 b 10 b 30 a 50 d 70 d 90 d 110 c 130 c 150 a 170 d 190 c 11 c 31 c 51 d 71 a 91 c 111 a 131 d 151 b 171 c 191 c 12 c 32 c 52 d 72 a 92 c 112 d 132 c 152 c 172 d 192 b 13 c 33 a 53 c 73 c 93 c 113 c 133 d 153 a 173 b 193 b 14 d 34 d 54 b 74 d 94 a 114 d 134 b 154 d 174 a 194 c 15 d 35 a 55 a 75 a 95 a 115 a 135 c 155 a 175 a 195 a 16 b 36 c 56 b 76 b 96 b 116 c 136 c 156 b 176 c 196 b 17 d 37 a 57 c 77 c 97 c 117 c 137 d 157 c 177 d 197 c


18 c 38 a 58 d 78 a 98 a 118 b 138 b 158 b 178 b 198 b 19 a 39 d 59 d 79 a 99 c 119 b 139 d 159 c 179 d 199 a 20 c 40 a 60 d 80 c 100 c 120 c 140 b 160 a 180 c 200 b

3.EFFECTS OF ELECTRIC CURRENT 1.The heat developed in half a minute , in a resistor of resistance 5 is 15,000 joule, the current through the resistor is a) 5A b) 100A c) 40A d) 10A 2. 5A of current flowing through a resistor for 2minutes produces 3000J of heat .The value of the resistance is a) 1 b) 2 c) 4 d) 5 3.Seebeck effect is a) reversible process b) converse of Peltier effect c) irreversible process d) all the above 4.A thermocouple uses a) Joule effect b) Seebeck effect c) Thomson effect d) all the above 5.Seebeck effect produces a) heat only b) either heat or cold c) thermo emf d) cold only 6.Thermo emf does not depend on a) the material of the wire b) temperature of the hot junction c) length of the conductors d) temperature of the cold junction 7.At neutral temperature , the thermo emf a) increases b) decreases c) is constant d) zero 8.The neutral temperature depends on the a) temperature of hot junction b) temperature of cold junction c) metals in the thermocouple d) all the above 9.The Peltier effect is maximum at ……. Junction a) hot b) cold c) hot and cold d) all the above 10.Current carrying conductors relates a) electric field b) magnetic field c) electrostatic field d) all the above


11.Maxwell’s right hand cork screw rule gives a) strength of the electric current b) direction of the current c) strength of the magnetic current d) direction of the magnetic field 12.At the centre of the current carrying plane loop, the lines of force is …… to the plane of the circular loop. a) parallel b) perpendicular c) tangential d) radial 13.When I ampere current is passed through long straight conductor then the magnetic induction at a point on the conductor is a)zero b) infinite c) 2I/r d) 0 /2a 14.A charged particle entre at right angles into a uniform magnetic field is a) straight line b) circular path c) elliptical path d) parabolic path 15.Magnetic induction at the centre of the current carrying circular coil is a)proportional to the radius of the coil b) inversely proportional to radius of the coil c) proportional to the square of radius of the coil d)inversely proportional to the square of the radius of the coil 16.If the radius of the coil halved and number of turns doubled , then the magnetic field at the centre of the coil carrying current will be a) get doubled b) get halved c) become four times d) remains unchanged 17.A tangent galvanometer shows same deflection at two different places. It implies that in both places a) current is same b)BH is same c)both current and BH same d) either(a) or (b) 18.Workdone by a Lorentz force is a)zero if =900 b) zero if =450 c) always zero d) maximum if =900 19.For a solenoid whose length is very large compared to its radius the magnetic field at points outside the solenoid is a) maximum b) minimum c) zero d) 1/0 20.An alpha particle enters a magnetic field of 1 tesla with a velocity 106 m/s in a direction perpendicular to the field. The force on alpha particle is a) 1.6x10-13N b) 6.4x10-13N c) 4.8x10-13N d) 3.2x10-13N 21.The period of revolution of a charged particle inside a cyclotron does not depend on a) the magnetic induction b) the charge of the particle


c) the velocity of the particle d) the mass of the particle 22.The torque on a rectangular coil placed in a uniform magnetic field is large when a) the number of turns is large b) the number of turns is less c) the plane of the coil is perpendicular to the field d) the area is small 23.The resultant magnetic momentum of an electron is due to a) the spin motion alone b) the orbital motion alone c)both the spin and orbital motion d) neither (a) or (b) 24.For steady current I, the amount of heat produced in time ‘t’ is a) VIt b) V2It c) I/Vt d) VI2t 25.When the number of turns in a galvanometer is increased the voltage sensitivity a) increases b) decreases c) remains constant d) either (a) or (b) 26.A galvanometer of resistance G is shunted with S the effective resistance of the combination is Ra. Then which of the following statements is true? a) G is less than S b) S is less than Ra but greater than G c) Ra is less than both G and S d) S is less than both G and Ra 27.In which of the following , Joule heating effect undesirable ? a) electric iron b) electric toaster c) transformer and dynamos d) fuse wire 28.Which one of the following is not a thermoelectric effect? a) Peltier effect b) Thomson effect c) Joule effect d) Seebeck effect 29.Position of the metal in the thermoelectric series depends on a) temperature b) nature of the metal c) magnitude of thermo emf d) atomic number of metal 30.Electric filament lamp is working on the basis of a) Joule’s heating effect b) Peltier effect c) Thomson effect d) Seebeck effect 31.Heating element of an electric heater should be made with a material which should have a) high specific resistance and high melting point b) high specific resistance and low melting point c) low specific resistance and low melting point d) low specific resistance and high melting point


32.Two identical wires are first connected in series and then in parallel with a voltage source. The ratio of heat developed in two cases is a)2:1 b) 1:2 c) 4:1 d)1:4 33.Current is flowing through a conductor of resistance 10 ohm indicate in which of the following cases the maximum heat will be generated. a) 5A passing for 2 minute b) 4A passing for 3 minute c) 3A passing for 6 minute d) 2A passing for 5 minute 34.If the heating element of an electric toaster has resistance of 22 ohm and is connected to an voltage source of 110 V, the amount of heat generated in 1minute is a) 33KJ b) 22 KJ c) 66 KJ d) 3.3KJ 35.Magnetic induction at a point due to infinitely long straight conductor carrying current at a distance of ‘a’ from the axis a) directly proportional to ‘a’ b) directly proportional to a2 c) inversely proportional to ‘a’ d) inversely proportional to a2 36.In a tangent galvanometer , the plane of the coil should be adjusted to be in a) geographic meridian b) magnetic meridian c) any direction d) parallel to east-west direction 37.If the reduction factor of a tangent galvanometer is 0.866 A , then the current that produces a deflection of 300 a) 450mA b) 500mA c) 780 mA d) 520A 38.Fuse wire has a)37%lead and 63% tin b) 63% lead and 37% tin c) 37% copper and 63% tin d) 63% copper and 37% tin 39.An electron is moving with a velocity of 3x106 m/s perpendicular to a magnetic field of 0.5T, then the force experienced by the electron is a)24x10-14N b) 24x10-13 N c) 13.6x10-27 N d) 13.6x10-11 N 40.An -particle with (e/m)ratio 4.8x108 C kg-1travels in a circular path of radius 0.45m in a magnetic field of 1.2T, then the speed of the - particle is a) 2.6x104 m/s b) 2.6x105 m/s c) 2.6x108 m/s d) 1.3x107 m/s 41.Tangent law is used when a) two uniform and mutually perpendicular magnetic fields are present b) two uniform and mutually parallel magnetic fields are present c) two magnetic fields are present


d) horizontal component of the earth’s magnetic field is present 42.If a current carrying loop is placed in a magnetic field by its plane a) perpendicular to the field ; it will rotate b) perpendicular to the field; it will not rotate c) parallel to the field ; it will not rotate d) perpendicular or parallel ; it will not rotate 43.When the number of turns ‘n’ in a galvanometer is doubled, current sensitivity a) remains constant b) decreases twice c) increases twice d) increases four times 44. When the number of turns ‘n’ in a galvanometer is doubled, voltage sensitivity a) remains constant b) decreases twice c) increases twice d) increases four times 45.The deflection in moving coil galvanometer is reduced to half, when it is shunted with a resistance of 40 ohm, then the resistance of the galvanometer will be a) 80 ohm b) 40 ohm c) 20 ohm d)10 ohm 46.A galvanometer of resistance 50 ohm is shunted with a wire of 10 ohm. The current through the galvanometer when the current in the circuit is 12 A is a)3A b) 2A c) 5A d) 6A 47.The unit of reduction factor of tangent galvanometer is a) No unit b) tesla c) ampere d) ampere/ degree 48.Thermopile is used to a) measure temperature b) measure current c) detect thermal radiation d) measure pressure 49.The torque experienced by a rectangular current loop placed perpendicular to a uniform magnetic field is a) maximum b) zero c) minimum d) infinity 50.Which of the following produces large Joule heating effect? a) 1A current through 2resistor for 3 second b) 1A current through 3resistor for 2 second c) 2A current through 1resistor for 2 second d) 3A current through 1resistor for 1 second 51.A galvanometer of resistance G ohm is shunted with S ohm. The


resistance of ammeter so formed is Ra, then which of the following statement is wrong? a) G S b) Ra S G c) Ra S d) Ra S G 52.When a charged particle moves perpendicular to a magnetic field its kinetic energy a) increases b) decreases c) does not change d) becomes zero 53.Two identical galvanometer are converted into ammeters using shunts of values S1 and S2 . S1 is used to measure milli ampere and S 2 to measure ampere . Then a) S1 S2 b) S1 S2 c) S2 = 1000S1 d) S1+ S2 = 1000 54.In cyclotron , the time period of rotation of a charged particle depends on a) velocity of the particle b) radius of the circular path c) magnetic induction d) high frequency electric field 55.The metal which is not having negative Thomson effect a) Bi b) Ni c) Cd d) Co 56.The direction of force on a current carrying conductor placed in a magnetic field is given by a) Fleming’s left hand rule b) Fleming’s right hand rule c) End rule d) Right hand palm rule 57.The neutral temperature of a thermocouple depends on a) temperature of cold junction b) temperature of hot junction c) metals which make the thermocouple d) none of these. 58.The radius of the circular path of an electron moving in a uniform magnetic field is directly proportional to a) the velocity ‘v’ b) 1/ mass of the electron c) charge ‘q’ of the electron d) magnetic field ‘B’ 59.Cyclotron could not accelerated the electrons because a) electron has low mass b) the velocity of electron is high c) there is a relative mass variation of electron at high velocity d) the radius increases when the electron is on motion 60.The current sensitivity of a galvanometer decreases by increasing a) the magnetic field b) the area of the coil c) the couple per unit twist of the suspension wire d) the number of turns 61.The voltage sensitivity of a galvanometer does not change by changing


the value of a) the magnetic field b) area of the coil c) couple per unit twist d)the number of turns 62.In an ammeter the amount of current flowing through low resistance is given by a) Is =I(Ig /S+G) b) Is =I g(G /S+G) c) Is =G(I /I+Ig) d) Is =I(G/S+G) 63.An - particle moves with a speed of 5x105ms-1 at an angle of 300with respect to a magnetic field of induction 10-4T. Then the force acting on the particle is a) 4x10-15 N b) 8x10-18 N c) 16x10-16N d) 4x10-3 N 64.A current of 5A flows through two long straight parallel wires kept at a distance 10 cm in air . Then the force acting between them per unit length is a) 4.9x10-5N b) 25x10-7N c) 5x10-5N d) 10x10-6N 65.The period of rotation of an electron moving in circular path in a magnetic field of induction 1 tesla normal to it is a)6.28x10-19s b) 3.58x10-11s c) 6.25x10-9s d) 1 s 66.The amount of heat energy evolved or absorbed in Peltier effect is a) low at cold junction ; high at hat junction b) high at cold junction ; low at hat junction c) twice at the hot junction as that of the temperature at cold junction d) equal on both junction 67.In a cyclotron, the frequency of accelerated charge increases a) with increase in its mass b) with increase in magnetic field c) with decrease in magnetic field d) with decrease in its charge 68.In a moving coil galvanometer , the hemispereical magnetic poles produce a magnetic field in which the plane of the coil is ---- to the field in all position a) perpendicular b) parallel c) maximum d) zero 69.The low resistance connected to a galvanometer to get an ammeter of desirable range is a) S= GI/I-Ig b) S= GIg/ I-Ig c) S= G(Ig-I) / Ig d) S= G(Ig-I) / I 70.The current flowing through the galvanometer in an ammeter is given by a) Ig=IS/S+G b) Ig=IG/S+G c) Ig=IS/S-G d) Ig=IG/S-G 71.The magnetic field produced at a point 20 cm from a long straight conductor carrying current 5A is


a) 10x10-6T b) 4x10-6 T c) 2.5x10-6 T d) 5x10-6T 72.The resistance of the filament of a 60W, 220 V electric bulb is a) 4k b) 960 c) 250 d) 1440 73.Galvanometer has a resistance 100. It shows full scale deflection for a current of 1mA . Then the resistance required to convert it into0-10 V range Voltmeter is a) 900 b) 9900 c) 9500 d) 4500 74. Galvanometer has a resistance 100. It shows full scale deflection for a current of 50mA . Then the resistance required to convert it into0-5A range Ammeter is a) 0.1 b) 100/999 c) 0.01 d) 100/99 75.Two parallel wire each of length 10m are placed at a distance of 5 cm. They carry a same current 3.5A in the same direction . Then the attractive force between them is a)4.9x10-4 N b) 3.6x10-4N c) 2.5x10-6N d) 1.6x10-5 N 76.The heat energy developed in a conductor of resistance 10 when 5A current flows through it for a minute is a) 15000 J b) 3000J c) 120J d) 1500J 77.A conductor of length 50 cm is placed perpendicular in a uniform magnetic field . When 5A current flows through it, the force acting on the conductor is 5x10-3 N , then find the value of magnetic field. a) 10x10-3T b) 4x10-3N c) 2x10-3T d) 6x10-3T 78.The magnetic field of induction at the centre of circular coil of radius 5cm carrying current 2A is a) 10x10-7 T b) 40x10-6 T c) 8x10-6 T d) 16x10-6T 79.A 500 mA current flows through a galvanometer coil makes it to turn through an angle / 5 radian. If the galvanometer coil has 100 turns , then the galvanometer constant is a) 100 / mA rad-1 b) 2500 / mA rad-1 c) 500 / mA rad-1 d) 20 / mA rad-1 80.A moving coil galvanometer of resistance 20 produces full –scale deflection for a current of 50mA . The resistance required to convert the galvanometer into a voltmeter of range 20V is a) 2380 b) 1980 c) 1480 d) 380 81.The force acting on a charge kept in a uniform magnetic field of induction is


a) inversely proportional to the charge b) zero c) maximum if the motion is anti parallel to the field d) inversely proportional to the magnetic field 82.Identify the metal in which positive Thomson effect was not occurred a) Au b) Hg c) Ag d) Zn 83.A galvanometer has a resistance of 100. A shunt resistance 1 is connected across it. What part of total current flows through the shunt ? a) 100/101 b) 1/101 c) 101/100 d) 99/100 84.Amount of heat released in any one of the junctions of a thermocouple when 60C charge passes through it is 3600J. Its Peltier coefficient is a) 0.0167 J/C b) 60 J/C c) 2.16x105 J/C d) 3600 C/J 85.Flux through galvanometer is 5x10-4 Wb, couple per unit twist is 25x10-5 N rad-1 and number of turns is 20. Its current sensitivity is a) 40 radA-1 b) 2 radA-1 c) 10 radA-1 d) 200 radA-1 86.The magnetic induction at a point 1m away from a long conductor carrying current of 1A is a) 2x10-5T b) 2x10-7T c) 2 x10-5T d) 2 x10-7T 87.The frequency of cyclotron to accelerated a proton in the field of 0.5T is a) 7.6x10-6 Hz b) 76 Hz c) 7.6x106 Hz d) 76x106 Hz 88.What will be the value of resistance added to galvanometer to convert it into a voltmeter of range 20V having resistance 40 and current 2 mA? a) 9960 in series b) 9960 in parallel c) 40 in series d) 1000 in parallel 89.A long straight wire carrying current produces magnetic induction of 4x10-6 T at a point 150cm from the wire. The current through the wire is a) 15A b) 30A c) 3A d) 1.5A 90.The resistance to be connected with the galvanometer to convert it into voltmeter of range 5V with current 50mA and galvanometer resistance of 20 is a) 80 in parallel b) 80 in series c) 800 in parallel d) 800 in series 91.The galvanometer has a resistance of 40 and current 5 mA . the shunt to be connected to make it an ammeter of range 2 A is a)0.1 b) 40 k c) 39 d) 0.399


92.In a moving coil galvanometer , the deflection of the coil ‘’ is related to the electric current ‘I’ by the relation a) I tan b) I c) i 2 d) i 93.Peltier co-efficient of a junction of a thermocouple depends on the pair of metals in contact and a) the current in the thermocouple b) time for which the current flows c) temperature of the junction d)charge that passes through the junction 94.The deflection of a galvanometer falls from 50 divisions to 10 divisions when 12 resistance is connected across the galvanometer. Then the resistance of the galvanometer is a) 48 b) 96 c) 120 d) 12 95.Amount of heat dissipated per second in a wire of resistance 5 through which a current of 5A flows is a) 125 Js-1 b) 250 Js-1 c) 50 Js-1 d) 75 Js-1 96.The magnetic field inside a solenoid is given by a) infinite b) 0nI c) zero d) nI 97.A magnetic field exerts no force on a) a current carrying conductor b) a magnet c) a stationary charge d) an unmagnetized iron bar 98.A charged particle of mass 3.2x10-27kg and charge 1.6x10-19C moves in a circular orbit under the influence of perpendicular magnetic field of strength 3.14 T , then the period of revolution of the particle is a) 10-8 s b) 2x10-8 s c) 3x10-8 s d) 4x10-8 s 99.When two resistance ,R1 and R2 are connected in parallel , to a source of emf ,ratio of heat produced is a) R2 / R1 b) R1

2 /R22 c) R1 / R2 d) R2

2 /R12

100.When the number of turns in a galvanometer is doubled , then a) current sensitivity and voltage sensitivity doubled b) current sensitivity is doubled and voltage sensitivity remains unchanged c) current sensitivity remains unchanged d) voltage sensitivity is doubled 101.When two resistance ,R1 and R2 are connected in series , to a source of emf ,ratio of heat produced is a) R2 / R1 b) R1

2 /R22 c) R1 / R2 d) R2

2 /R12


102.How many 100w bulbs may be safely used on 220V with 5A fuse? a) 22 b) 11 c) 10 d) 20 103.The graph of variation of thermo emf with temperature of hot junction () indicates the following a) For n emf increases and for n decreases with temperature b) For small difference in temperature , it is a straight line graph c) For large difference in temperature , it is a parabola d) all of there 104.Which of the following statement is incorrect? a) both Peltier and Thomson effects are reversible b) Joule effect is reversible but not the Peltier effect c) Joule effect is irreversible ,where as Thomson effect is reversible d) the temperature of inversion of a thermocouple depends on the temperature of cold junction. 105.If the radius of the coil and the number of turns are doubled , then the magnetic field at the centre of the coil, for the same current will a) get doubled b) get halved c) remain same d) get quadrupled 106.Tangent galvanometer is most sensitivity if a) B BH b) B BH c) B BH d) B = BH 107.If the radius of the coil halved and the number of turns are doubled , then the magnetic field at the centre of the coil, for the same current will a) get doubled b) get halved c) remain same d) get quadrupled 108.By passing a current through the coil of T.G. , if the magnetic field at the centre becomes equal in magnitude to that of horizontal component of earth’s magnetic field , then the deflection is a) 900 b) 00 c) 450 d) 600 109.Solenoid is commonly used to obtain a) strong magnetic field b) uniform magnetic field c) decreasing magnetic field d) increasing magnetic field 110.Magnetic induction at the centre of circular coil of radius 10 cm with 500 turns is 12.56x10-3T. The current in the coil is a) 1 A b) 2A c) 3A d) 4A 111.By passing a current in the coil , the magnetic field produced at the


centre is 22T. If an iron rod is inserted in the coil, the magnetic field is a) 22T b) 22T c) =22T d) zero 112.The radii of the coils of two T.G are in the ratio 2:1. By passing same current , if they show equal deflections , the number of turns are in the ratio a) 1:2 b) 2:1 c) 1:1 d) 1:4 113.A T.G. gives a deflection of 300 for certain place and 450 at another place .The ratio of horizontal components of earth’s magnetic field at two place is a) 1:3 b) 3 : 1 c) 3:1 d) 1:3 114.The period of circular motion of a charged particle in a magnetic field a) depends on its velocity alone b) depends on the radius of the path alone c) depends both on velocity and radius of the path d) is independent of both its velocity and radius of its orbit 115.The magnetic field of induction applied to a cyclotron is 0.3T.The frequency of the RF oscillator required to accelerate a particle of mass 1.67x10-27kg and charge 1.6x10-19 C is a) 4.577 Hz b) 45.77 Hz c) 4.577MHz d) 45.77 KHz 116.A wire of length 50 cm carrying a current of 2A is placed inside a field of magnetic induction 10T, such that it makes an angle of 600 with the normal to the field .The force on the wire is a) 5N b) 10N c) 15N d) 20N 117.Two parallel conductors of length 20 cm each, carry currents 4A and 3A in same direction . The force between them when they are 3cm apart is a) 1.6x10-5 N repulsive b) 3.2x10-5 N attractive c) 3.2x10-5 N repulsive d) 1.6x10-5 N attractive 118.A singly charged ion of mass 12.8x10-27kg moving with the speed of 6x106 ms-1 , describes a circular path of radius 1.5 m . The magnetic field applied perpendicular to its path a) 0.21 T b) 0.45 T c) 0.32T d) 0.8T 119.If a galvanometer giving full deflection for 20 mA is converted into a voltmeter to read 60V by connecting 2970 in series, the resistance of the galvanometer is


a) 60 b) 30 c) 90 d) 130 120.An electron in hydrogen atom moves in an orbit of radius 0.5A . If the magnetic moment associated with orbital motion is 1.256x10-23Am2 , the period of revolution of electron must be a) 10-16s b) 10-6 s c) 3.14x10-16 s d) 1.57x10-16s 121.What is relation between the voltage sensitivity v and current sensitivity i of moving coil galvanometer, when G is galvanometer resistance a) v = Gi b) v =i/G c) v =I d) none of these 122.The direction of the force experienced by a charged particle moving with a velocity ‘v’ in a uniform magnetic field B is a) parallel to v and perpendicular to B b) parallel to B and perpendicular to v c) parallel to both v and B d) perpendicular to both v and B 123.If only 2% of the current is to pass through a galvanometer of resistance G, then resistance of shunt will be a) G/50 b) G/49 c) 50 G d) 49G 124.A conductor of length l meter , carrying a current of I ampere is placed to the direction of the magnetic field of induction B. The force acting on the conductor per unit length is a) BIl b) zero c) BI d) –Bil 125.If a shunt of 1 is connected to a galvanometer of (n-1), then the fraction of current that flows through galvanometer is a) n2 b) n-1 c) n+1 d) n-1 126.Period of rotation of a charged particle in a uniform magnetic field does not depend upon a) charge b) magnetic induction c) velocity d) mass 127.5 A of current flowing through a resistor for 2minute produces 3000Jof heat. The value of resistance is a) 1 b) 2 c) 4 d) 5 128.In joule’s experiment the heat capacity of the calorimeter and content is 150 J/K. If the initial and final temperature are 290C and 490 respectively, then the heat developed is a) 150J b) 3 kJ c) 7.5 J d) 300J


129.In joule’s experiment through a given resistor, a current of 5A and 7A are passed successively for the same interval of time .Then the heat developed in the two cases are in the ratio a) 5:7 b) 25:49 c)7:5 d) 49:5 130.In Joule’s experiment some current is passed through two resistors 2 and 6 for same interval of time . Then the ratios of heat developed in the two cases is a) 1:9 b) 6:2 c) 1:3 d) 9:1 131.Which one of the following is not correct responding joule’s calorimeter experiment? a) H/R2 = constant b) H/I2 =constant c) H/R = constant d) H/t = constant 132.In Joule’s calorimeter experiment, the water equivalent is 421 JK-1.The increase in temperature of the calorimeter and content is 9K. The amount of heat liberated by heating element is a) 421 J b) 3789J c) 46.8 J d) 4304J 133.Fuse wire is an alloy of a) lead and tin b) tin and copper c) lead and copper d) lead and iron 134.Fuse wire a) is an alloy of lead and copper b) has low resistance c) has high resistance d) has high melting point 135.Nichrome is used as a heating element because it has a) low specific resistance b) low specific conductance c) high melting point d) all the above 136.Choose the correct statement a)Nichrome has low resistance and high melting b) Fuse wire has high resistance and low melting point c) Nichrome has high resistance and low melting d) Fuse wire has low resistance and high melting point 137.A current of 2A flows through a resistor for 8s and a current of 8A flows through the same resistor for 2s,the ratio of the heats developed will be a) 2:4 b) 1:2 c) 1:1 d) 1:4 138.In the following thermocouple , the direction of the thermo electric current at the hot junction is from a) Sb to Bi b) Ni to Fe c) Fe to Cu d) Zn to Pt


139.The heating element that does not oxidize readily is an alloy of metals made of a) Nickel and Iron b) Nickel and Chromium c) Copper and Iron d) Nickel and Copper 140.Above the neutral temperature the thermo emf a) changes sign b) is constant c) increases with the rise in temperature d) decreases with the rise in temperature 140.For a given thermocouple the neutral temperature a)depends upon the temperature of cold junction b) depends upon the temperature of hot junction c) depends upon the temperature of both cold and hot junction d) is a constant 142. For a given thermocouple ,the cold junction temperature 300C and neutral temperature is 1200 C .If the cold junction temperature becomes 500C, then the neutral temperature becomes a) 1400C b) 1200C c) 1000C d) 1700 C 143. When the hot and cold junctions of a thermo couple are interchanged then the thermo emf a) increases b) remains unchanged c) decreases d) increases or decreases according to nature of metals used. 144.For a given thermo couple , the temperature of cold junction and temperature of inversion are 253K and 8500 C. The neutral temperature is a) 4350 C b) 4150 C c) 551.50 C d) 4250 C 145.To draw thermo electric diagrams Lead is used as one of the metal to form a thermo couple with other metal because a) it is a hard metal b) it has high nuclear density c) it does not allow X-rays d) it has zero Thomson effect 146.A charged particle moves through a steady magnetic field . The effect of the field is changed the particles a) speed b) direction c) mass d) energy 147.The force on a proton moving with the speed of 105m/s perpendicular to a magnetic field 10-3T is a) 1.6x10-17N b) 1.6x10-27N c) 1.6x10-19N d) 10-2N


148.If a proton and a deuteron move in a magnetic field along the same circular path, then the ratio of their velocities is a)1:1 b) 4:1 c) 1:2 d) 2:1 149.A deuteron and an alpha particle move in a uniform magnetic field along the same circular path , then the ratio of their velocities is a)1:1 b) 4:1 c) 1:2 d) 2:1 150.If 1H1 and 1H2 are moving perpendicular to a uniform magnetic field with same velocity, then the ratio of the radii of their circular path is a)1:1 b) 4:1 c) 1:2 d) 2:1 151. If a deuteron and an alpha particle are moving perpendicular to a uniform magnetic field with same velocity, then the ratio of the radii of their circular path is a)1:1 b) 4:1 c) 1:2 d) 2:1 152. If -1e0 , 1H1 ,1H2and 1 H3 are moving perpendicular to a uniform magnetic field with same velocity, then the force on a) -1e0 is maximum b) 1 H3 maximum c) 1H1 is greater than others d) all the particle are same 153.Which one of the following pair of particles move with the same velocity along the same circular path in a uniform magnetic field a) electron, proton b) proton, deuteron c) proton, alpha particle d) deuteron, alpha particle 154.A current carrying conductor is placed perpendicular to a uniform magnetic field of induction 10-5 T . If the drift velocity of the free electron is 106 m/s , then the force experienced by one free electron is a) 1.6x10-18 N b) 1.6x10-13N c) 1.16x1019N d) 1N 155.A proton and deuteron move in a magnetic field in a circular path with same velocity. Which of the following are true? i) force on two particles is same ii) radii of the circular paths are same iii) force is same but radii of the paths are difference iv) force is different but radii of the paths are same a) i and iii only b) ii and iv only c) i and ii only d) ii and iii only 156.Two long parallel wires separated by a distance R carry same current. The force between the two wires is F. If the current in each wire is halved ,the force between them will be a) 4F b) F c) F/4 d)F/8 157.Which of the following material has the highest specific resistance a) rubber b) copper c) silver d) germanium


158.Force on unit length of a conductor carrying unit current placed perpendicular to a magnetic field is numerically equal to a) magnetic induction b) charge on a electron c) drift velocity d) force on one electron 159.The magnetic induction at a distance of 0.5m from a conductor carrying 2A current kept in air is a) 1x10-7 T b) 2 x10-7 T c) 4 x10-7 T d) 8 x10-7 T 160.A circular coil of 50 turns has a diameter 14 cm . When a current 2A is passed through , if the angle between the direction of the magnetic field and the plane of the coil at the centre of the coil is a) 300 b) 450 c) 600 d) 900 161.In a T.G. experiment , if the number of turns is increased 10 times , to produce the same deflection , the value of the current should be a) increased by 20 times b) increased by 10 times c) decreased by 20 times d) decreased by 10 times 162.For a given T.G. , if the number of turns in the coil is doubled then the reduction factor a) increases by 2 times b) decreases by 2 times c) increases by 4 times d) decreases by 4 times 163.Two T.G’s having reduction factor K1 and K2 are connected in series and give deflections 1 and 2 respectively. Then K1:K2 a) 1: 2 b) tan1: tan2 c) 2: 1 d) tan2: tan1 164.The tangent galvanometer has 50 turns of diameter 10 cm. If B=3.14x10-5T, the reduction factor is a) 0.4A b) 0.05A c) 0.4x10-3A d) 0.4x10-6A 165.The reduction factor of the T.G. when the deflection is 450 is equal to a) the number of coils b) the earth’s magnetic field c) the current in the coil d) all the above 166.For measuring high current, by using a T.G. a)less number of turns with thick copper wire is used b) less number of turns with thin copper wire is used c) large number of turns with thick copper wire is used d) large number of turns with thin copper wire is used 167.The least count of the T.G. for measuring the angle of deflection is a) 10 b) 1’ c) 0.50

d) 0.10


168.The T.G.is more sensitive for this angle of deflection a) 3.14 radian b) 45 radian c) 0.785 radian d) 1.57 radian 169.A T.G. gives a deflections of 1, 2 and 3 at the places A, B and C respectively for the same current. If the horizontal components of earth’s magnetic fields at the places A, B and C are BA , BB and BC respectively . Then the ratio BA:BB:BC is a) tan1: tan2: tan3 b) 1; 1: 1 c) 1: 2 : 3 d) cot1: cot2: cot3 170.Ampere’s circuital law is another form of a) Tangent law b) Biot- Savart law c) Ampere’s Swimming law d) End rule 171.What happens when the hot junction of a thermo-couple is heated beyond the temperature of inversion a) there is no thermo electric current b) thermo electric current is maximum c) thermo electric current reverse its direction d) predictable 172.The work done by magnetic Lorentz force on a moving charge is always a) positive b) negative c) zero d) infinite 173.The magnitude of the magnetic Lorentz force does not depend on a)mass of the charged particles b) velocity of the charged particle c) magnetic induction d) direction of the motion of the particle 174.Magnetic Lorentz force makes a moving charged particle to follow a a) linear path b) parabolic path c) elliptical path d) circular path 175.The force on a current carrying conductor placed in a magnetic field is 10-6N .If the current through the conductor is doubled then the force is a) 20-6 N b) 2x10-6 N c) 2x10-19 N d) 10-12 N 176.In two parallel wire one wire is carrying 1A and the another is carrying 3A. Then the force on a) the second wire is more b) the first wire is more c) both wires are same d) the second wire is 3times the first wire 177.In two parallel wires, one wire is carrying 1A and another carrying 3A. If the currents in the wire are interchanged , then the force on a) the second wire decreases b) the first wire decreases c) both wires will increases d) both wires will not change 178.Torque acting on a coil is maximum when the coil is a) parallel to the magnetic field


b) perpendicular to the magnetic field c) at an angle of 450 to the magnetic field d) at any position in a uniform magnetic field 179.The hemispherical magnet is used to produce a) radial magnetic field b) uniform magnetic field c) straight magnetic field d) circular magnetic field 180.In an ammeter if G:S =100:1 then the ratio of current through them is a) 100:1 b) 1:100 c) 10:1 d) 1:10 181.A moving coil galvanometer shows a deflection of 120, when a current of 1mA flows through it. If the current is 2mA , then the deflection will be a) 100 b) 120 c) 140 d) 240 182.If a current 0.5 mA produces a deflection of 150, then the galvanometer constant is about a) 0.33 a rad-1 b) 2Arad-1 c) 3 A rad-1 d) 7.5 a rad-1 183.A moving coil galvanometer shows a deflection of 100 for a current

of 0.7 mA . For another current , if the deflection is 150, then the value of current is a)10.5 mA b) 1.05mA c) 0.35mA d) 3.5 mA 184.The low resistance connected in parallel with the galvanometer so as to avoid the flow of large current through it is called a) resistor b) capacitor c) solenoid d) shunt 185.The minimum value of orbital magnetic moment of revolving electron in an atom is called a) angular momentum b) Bohr magneton c) gyromagnetic ratio d) Planck’s constant 186.AB is a rod of lead. The end A is heated .A current I is allowed to flow along AB. Now ,due to Thomson effect, in rod AB a) heat is absorbed b) heat is liberated c) heat is neither absorbed nor liberated d) heat is first absorbed and then liberated 187.A current of 5A is passed through a super conductor for 10J the heat energy evolved is a) 250J b) 25J c) zero d) 50J 188.Nichrome is used as heating element in devices like electric iron


because it a) cools of quickly when power is put off b) generates large amount of heat in short time c) has low expansion co – efficient d) does not oxidize 189.The thermo – couple, which has the maximum thermo emf, is _ a) Cu – Fe b) Mn – Ag c) Bi – Sb d) Co – Au 190.The graph of the thermo emf versus the temperature difference in a thermocouple is a) straight line b) a parabola c) a hyperbola d) a circle 191.The ratio between the Bohr magneton and the gyro magnetic ratio is a) h/4 b) h/ c) h/2 d) h

192.A graph drawn between thermo emf and small difference in temperature between the function is a a) parabola b) straight line c) curve d) ellipse 193.While doing experiment with T.G. the circular coil must be

a) inclined to the magnetic meridian b) parallel to magnetic meridian c) perpendicular to magnetic meridian d) in any position

194.The magnetic needle of a T.G. is kept small because the magnetic field is a) very large b) considered to be uniform c) very small d) consider to be uniform at the centre only 195.The magnetic Lorentz force is the force acting on a) a charged particle at rest b) a charged particle moving in an uniform magnetic field c) a wire carrying current d) a positive charge 196.When a current carrying rectangular loop is placed in a magnetic field the resultant of forces acting on the top and bottom of the current loop is a) zero b) maximum c) infinity d) minimum 197.The voltage across the shunt resistance a) is less than the voltage across the galvanometer b) is greater than the voltage across the galvanometer c) is equal to the voltage across the galvanometer d) none of the above 198.The product of the current and the loop area is called a) magnetic induction due to current loop


b) magnetic moment of the current loop c) magnetic induction of the centre of the current loop d) magnetic amount of the solenoid 199.If an electron is projected along z – axis with constant velocity in the presence of an applied magnetic field along X – axis, the force on it is a) along Z – axis b) against Y – axis c) along Y – axis d) against Z – axis 200.At the centre of circular current carrying coil, the magnetic lines of force are a) straight b) circular c) zig zag d) irregular II. IMPORTANT UNITS 1.The unit of Peltier co-efficient is ……… 2.The unit of Thomson coefficient is ………. 3.The unit of permeability of a medium is ……… 4.The unit of relative permeability is ……… 5.The unit of magnetic flux is ……… 6.The unit of magnetic flux density or magnetic induction is ……….. 7.The unit of reduction factor of the tangent Galvanometer is …….. 8.The unit of magnetic Lorentz force is ………. 9.The unit of angular velocity is ……… 10.The unit of time period is …………. 11The unit of galvanometer constant is …………….. 12.The unit of water equivalent is ……….. 13.The unit of torsional couple per unit twist is ………… 14.The unit of gyromagnetic ratio is ……….. 15.The unit of angular momentum is ………. 16.The unit of Planck’s constant is ………. 17.The unit of Bohr magneton is ……… III. STANDARD VALUES 1.The percentage of lead and tin in fuse wire is ……… 2.Melting point of tungsten is ………..


3.Thomson effect for lead is …….. 4.The tangent galvanometer is sensitive for a deflection of …… 5.Suspended coil galvanometer can measure current of the order of …… 6.The value of gyromagnetic ratio is ……… 7.The value of Bohr magneton is ………. 8.The value of Planck’s constant is ……… IV. IMPORTANT FORMULAE 1.According to Joule’s law the heat produced in a conductor is …… 2.I n any thermocouple the neutral temperature is ……….. 3.The quantity of heat absorbed or evolved at one junction of a thermocouple

is……… 4. According to Biot-Savart law , the magnetic induction at a point is …. 5. According to Biot-Savart law , the magnetic induction at a point in the

vector form is …. 6. Magnetic induction due to infinitely long straight conductor is ……. 7. Magnetic induction along the axis of a circular coil carrying current is

……….. 8. Magnetic induction at the centre of a circular coil is …… 9. Current through a T.G. is ……. 10. Reduction factor of a T.G. is ……. 11. Magnetic Lorentz force on a charge moving in magnetic field is ….. 12. Radius of a charged particle moving in a uniform magnetic field is

……… 13. Angular velocity of a charged particle moving in a uniform magnetic field

is…….. 14. Frequency of a charged particle moving in a uniform magnetic field is

………. 15.Time period of a charged particle moving in a uniform magnetic field is

…… 16. Force on a current carrying conductor placed in magnetic field is …….. 17. Force between two long parallel current carrying conductor is ……. 18. Torque experienced by a current loop in a uniform magnetic field is …. 19. Deflecting couple on a moving coil galvanometer is ……… 20. Restoring couple by a moving coil galvanometer is ………. 21. Current through a moving coil galvanometer is ………..


22. Galvanometer constant is ……. 23. Current flowing through an ammeter is ……… 24. Current sensitivity of a galvanometer is …….. 25. Voltage sensitivity of a galvanometer is ……… 26. The shunt resistance of an ammeter is ………… 27. Effective resistance of an ammeter is …….. 28. The resistance to be connected in series to convert a galvanometer into voltmeter is ………. 29. The effective resistance of a voltmeter is ………. 30. The magnetic moment of a revolving electron is ……….. 31. Magnetic dipole moment of a revolving electron is …….. 32. Bohr magneton is ………. V.THREE MARK QUESTIONS I. DEFINATIONS:

1. Define Peltier coefficient. 2. Define Thomson Coefficient. 3. Define ampere. 4. Define voltage sensitivity of a galvanometer. 5. Define current sensitivity of a galvanometer. 6. Define the magnetic moment of a current loop. 7. Define neutral temperature. 8. Define temperature of inversion. 9. Define gyro magnetic ratio. 10. Define Bohr magneton

II. LAWS AND PRINCIPLES

11. State Joule’s law. 12. State Maxwell’s right hand screw rule. 13. State Biot-Savart law. 14. State right hand rule. 15. State Seebeck effect. 16. State Peltier effect? 17. State Thomson effect. 18. State right hand palm rule. 19. State end rule.


20. State Fleming’s left hand rule. 21. State Tangent law. 22. State the principle of a moving coil galvanometer. 23. State the principle of cyclotron. 24. State Ampere’s circuital law. III.ADVANTAGES, DISADVANTAGES (LIMITATIONS) DRAW BACKS. 25. Mention the limitations of cyclotron. IV.PROPERTIES (CHARACTERISTICS) 26. What are the characteristics of heating element used in electric heating device? V.REASONING QUESTIONS

27. Why is nichrom used as a heating element? 28. Increasing the current sensitivity does not necessarily increase the voltage sensitivity. Explain 29. Why lead is used as one of the metal to form a thermocouple? 29. Why an ammeter is always connected in series in a circuit? 30. Why do we use phosphor bronze suspension wire in the moving coil galvanometer? 31. Why a voltmeter is connected in parallel in a circuit? VI.DISTINGUISHING AND DIFFERENTIATING QUESTIONS

32. Mention the difference between Peltier effect Joule’s effect. VII.THEORY QUESTIONS 33. How will you increase the current sensitivity of a galvanometer? 34. How will you convert galvanometer into ammeter? 35. How will you convert galvanometer into voltmeter? 36. What is a fuse wire? How does it work? 37. What is shunt? 38. What is magnetic Lorentz force? 39.What are thermo couple and thermo electric current?


VI. THREE MARK PROBLEMS 1.The heat developed in half a minute in a resistor of resistance 5 is 15000 J. Find the current through the resistor. 2. 5A current flowing through a resistor for 2minute produces 3000J of heat .Calculate the value of the resistance. 3.The Peltier coefficient of a thermo couple is 3mV.The heat liberated or absorbed in any one junction is 3.6 J when a current of 4A is sent through the thermo couple. What is the time of flow of current? 4.In a thermo couple the temperature of the cold junction is 1000C and the neutral temperature is 5000 C. Calculate the temperature of inversion. 5.In a given thermo couple , the neutral temperature is 2600C and the temperature of inversion is 4800C. Then find the temperature of the cold junction. 6.Calculate the magnetic induction at the centre of a circular loop of diameter 20 cm carrying a current 5A kept in air. 7.What is the reduction factor of a tangent galvanometer having 6 turn coil of diameter30 cm if the earth’s magnetic induction is 6.28x10-5T. 8.A current of 2A flows through a circular coil of area 4x10-2m2.Calculate the magnetic field at the centre of the coil. 9.When a current of 9A is passed through a coil 15cm radius a magnetic field of 37.68x10-5 T is produced at the centre of the coil. Find the number of turns of the coil. 10.What is the current passing through a coil of radius 8cm having 50 turns, when the magnetic induction at the centre of the coil is 15.7x10-5 T. 12.A current of1A flowing through a T.G. produces a deflection of 300.Calculate the current needed to produce a deflection of 450. 13.A solenoid of 1.5m length and 4 cm diameter possesses 100 turns per cm. A current of 5A is flowing through it. Find the magnetic induction along its axis inside the solenoid. 14.A proton enters into a magnetic field with a velocity of 2.5x107ms-1 making an angle of 300 with the deflection of the magnetic field of 2.5T. Then find the force on the proton. 15.An - particle enters into a magnetic field of 1T with a velocity 106 ms-1 in a direction perpendicular to the field . Calculate the force


on -particle. 16.Two conductors each of length 16m , parallel to each other with a distance of 10 cm between them carry the same current in the same direction in air If the force tending to pull them is 0.5 N. What is the current in them. 17.A current of 2A flows through two long straight conductors. They are placed parallel to each other at a distance of 10 cm. Calculate the force per unit length on each conductor 18.An ammeter of resistance 0.8 can measure current up to2A. What must be the shunt resistance to enable the ammeter to measure currents up to 10A? 19.A galvanometer has internal resistance of 20. It gives maximum deflection for a current of 30 mA. Find the resistance to be connected in series to convert it into a voltmeter of maximum reading of 3V. 20.A galvanometer of resistance 100 is shunted by 0.1 which gives maximum deflection for a current of 1mA .Calculate the range of an ammeter. 21.A current of 2A flowing in a coil of moving coil galvanometer produces a deflection of 100. Find the galvanometer constant. 22.In a T.G. a current 1A produces a deflection 300. Calculate the current required to produce a deflection of 600. 24.A current of 2A flows through a coil of area 0.02 m2. Find the magnetic moment of the loop. 23.A circular coil of 80 turns carries a current of 5A .If the diameter of the coil is 16 cm. Then calculate magnetic intensity produced at its centre. 25.The amount of heat liberated at one of the junction of a thermocouple when 1A current flows for 1 minute is 6J. Calculate the Peltier coefficient. VII.SHORT ANSWER (5 MARK QUESTIONS) 1. Write notes on Seebeck effect. 2.Write short notes on neutral and inversion temperature. 3. Explain Thomson effect. 4. Explain thermopile with the help.


5. State and explain Biot-Savart law. 6. What is magnetic Lorentz force? Discuss the special features of the force. 7. Obtain an expression for the force between two long parallel current

carrying conductors. 8. Explain how will you convert a galvanometer into an ammeter? 9. Explain how will you convert a galvanometer into voltmeter? 10. Deribe an expression for magnetic dipole moment of a revolving electron 11. Deduce an expression for the force on a current carrying conductor placed in a magnetic field. VIII. ESSAY TYPE QUESTIONS( 10 MARK) 1. Explain Joule’s calorimeter experiment to verify Joule’s laws of heating. 2. Obtain an expression for the magnetic induction at a point due to an infinitely long straight conductor carrying current. 3. Deduce the relation for the magnetic induction at a point along the axis of a circular coil carrying current. 4 Explain in detail the principle, construction and theory of a tangent galvanometer. 5.Explain in detail the principle ,construction and theory of moving coil galvanometer. 6.Explain the motion of a charged particle in a uniform magnetic field. 7.Describe the principle ,construction and working of a cyclotron. Derive an expression for the frequency of rotation of an accelerating particles. 8.Derive an expression for torque experienced by a current loop in a uniform magnetic field. KEY-3 LESSON

1 d 21 c 41 a 61 d 81 b 101 c 121 b 141 d 161 d 181 d 2 a 22 a 42 b 62 d 82 b 102 b 122 d 142 b 162 b 182 b 3 a 23 c 43 c 63 b 83 a 103 d 123 b 143 b 163 d 183 b 4 b 24 a 44 a 64 c 84 b 104 b 124 b 144 b 164 b 184 d 5 c 25 c 45 b 65 b 85 a 105 c 125 d 145 d 165 c 185 b


6 c 26 c 46 b 66 d 86 b 106 d 126 c 146 b 166 a 186 c 7 c 27 c 47 c 67 b 87 c 107 d 127 a 147 a 167 a 187 c 8 c 28 c 48 c 68 b 88 a 108 c 128 b 148 d 168 c 188 d 9 a 29 a 49 b 69 b 89 c 109 b 129 b 149 a 169 d 189 c 10 b 30 a 50 d 70 a 90 b 110 d 130 c 150 c 170 b 190 b 11 d 31 a 51 d 71 d 91 a 111 b 131 a 151 a 171 c 191 c 12 b 32 c 52 c 72 b 92 b 112 b 132 b 152 d 172 c 192 b 13 a 33 c 53 b 73 b 93 c 113 b 133 a 153 d 173 a 193 b 14 b 34 a 54 c 74 d 94 a 114 d 134 c 154 a 174 d 194 d 15 b 35 c 55 c 75 a 95 a 115 a 135 c 155 a 175 b 195 b 16 c 36 b 56 a 76 a 96 b 116 a 136 b 156 c 176 c 196 a 17 c 37 b 57 c 77 c 97 c 117 d 137 d 157 a 177 d 197 c 18 a 38 a 58 a 78 c 98 d 118 c 138 b 158 a 178 a 198 b 19 c 39 a 59 c 79 b 99 a 119 b 139 b 159 d 179176a 199 b 20 d 40 c 60 c 80 d 100 b 120 a 140 d 160 d 180 b 200 a

4.ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT 1.The reverse effect of Oersted experiments is a) Joule heating effect b) electrostatic induction


c) Peltier effect d) electromagnetic induction 2.The number of magnetic lines of force crossing a closed area is called a) magnetic induction b) magnetic flux c) magnetic intensity d) magnetic moment 3. The number of magnetic lines of force crossing a unit area normally is a) magnetic flux b) magnetic flux density c) magnetic intensity d) total flux 4.When 0.5A current passes through an inductor coil, the flux linked with it is 0.15Wb.Then the self inductance of the coil is a) 3H b) 0.45H c) 0.3H d) 0.2H 5.A current of 10A produces a magnetic flux of 1Wb when passing through a coil .The self inductance of the coil is a) 0.1H b) 10H c) 1000H d) 1H 6.In a coil an emf of 5V is induced when a current in the coil changes at the rate of 100A/s. The coefficient of self inductances of the coil a) 50H b) 0.05H c) 0.005H d) 0.0005H 7.If the time rate of change of current is doubled in a coil , then the value of self inductance is a) doubled b) halved c) not changed d) increased exponentially 8.When 5A current is passed for 0.5s in the primary coil, the emf induced in the secondary coil is 200V. The mutual inductance is a) 10H b) 20H c) 2H d) 4H 9.A current of 4A passing through a coil is cut off in 10-3s .Another coil has a mutual inductance of 40 mH with the first one. The emf induced in the second coil is a) 80v b) 100V c) 120V d) 160V 10.If two coils have a common axis, the coefficient of mutual induction is a) small b) zero c) large d) infinite 11.The mutual induction between a pair of coils is very large if they are wound on a) wood b) copper c) ebonite d) soft iron core 12.Eddy current do not cause a) damping b) heating c) sparking d) loss of energy 13.When the coil in an AC generator rotates at an angular velocity of 50 rad/s, the frequency of the induced emf is a) 100Hz b) 50Hz c) 25Hz d) 1000Hz


14.By making the core of the transformer laminated a) ratio of secondary voltage to primary voltage may be increased b) mass of the transformer may be reduced c) rusting of the core may be avoided d) energy loss due to eddy currents may be minimized 15.Which of the following quantities remain constant in an ideal step-down transformer a) current b) voltage c) power d) none of the above 16.When a transformer works ,sound is produced .This is due to a) heating of the core b) rotation of the core c) vibration of the core d) none of the above 17.In long distance power transmission which plays a very important role? a) resistor b) transformer c)capacitor d) inductance 18.The heat produced in one cycle when AC flows through a resistor is a) I2

rmsRT b) I20RT c) I2

rmsRT/2 d) zero 19.When a wire loop is rotated in a magnetic field, the direction of induced emf changes once in each a) ¼ revolution b) 1/2 revolution c) 1 revolution d) 2 revolution 20.Resistance offered by a coil is called a)resistance b) inductive reactance c) capacitive reactance d) inductance 21.The angular frequency of ACat which a coil of inductance 1mH has a reactance of 1 is a) 103 rad/s b) 10 rad/s c) 10-3 rad/s d) 1rad/s 22.The reactance of a coil a) increases with increase in frequency b)does not change with frequency c) decreases with increase in frequency d) is zero 23.Reactance of a capacitor of 1/ farad at 50Hz a) 100 b) 10 c) 50 d) 10-2 24.In an LCR series circuit the effective voltage leads the current by a phase angle when a) XL=XC b) XLXC c) XLXC d) XL=R 25.An Ac circuit contains 4 resistance in series with an inductance coil of reactance 3.The impedance of the circuit is a) 7 b) 5 c) 1 d) 4/3 26.For a sharply tuned circuit Q-values is a) zero b) low c) very low d) high


27.In an AC circuit , a resistance of R ohm is connected in series with an inductance L. If phase angle between voltage and current be 45 0, the value of inductive reactance will be a) R/4 b) R/2 c) R d) none of the above 28.The relation represents magnetic flux a) = B . A b) = B x A c) = BA sin θ d) (a) and (b) 29.The coefficient of mutual induction between two coils depends on a) The susceptibility of the medium b) the area of cross section of the coil c) The reciprocal of number of turns of coils d) size and shape of the coil 30.When the plane of the coil is parallel to the magnetic the emf induced in it is a) e = 0 b) e = NBA휔 c) e = Eo- sin 휔t d) e = NBA cos 휔t 31.When the phase of angle between the plane of the coil and the magnetic field is 휋/4, then the emf induced in the coil is a) e = Eo / 2 b) e = √2 Eo

c) e = Eo / √2 d) e = 0 32.The phase difference between the emf’s produced by a three phase generator is a) b) c) d) 33.A magnetic field of 15 x 10-5 tesla is acting through the axis of the coil of 25,000 turns and area of cross-section 250cm2 then the magnetic of flux linked with the coil is a)8.475 x 10-3 Wb b) 9.375 x 10-2 Wb c)5.225 x 10-3 Wb d)11.5 x 10-3 Wb 34.Regarding Faraday experiment about electromagnetic induction which of the following statement is incorrect? a) Only a momentary deflection is held in the galvanometer. b) The deflection will increase by moving the magnet faster. c) When the magnet is stable within the coil the induced emf is maximum d) When we change the poles of the magnet, the deflection will be held in the opposite direction. 35.When the plane of the coil is kept parallel to the magnetic field, then the emf induced is a) Zero b) Maximum c) Minimum d) Infinity 36. In an induction furnace, high temperature is produced by eddy currents by using ……….. magnetic fields to melt the metals


a) high frequency and varying b) high frequency and stable c) low frequency and stable d) low frequency and varying 37.To make the electromagnetic brake in the train when the wheels are rotating a strong magnetic field is applied …….. to the metallic drum which is coupled to the wheels a) Parallel b) to the direction opposite to the rotation of wheels c) Perpendicular d) to the direction of rotation of wheels 38. In a transformer, the eddy current loss is minimised by a) using a solid core made of stelloy, an alloy of steel b) using a laminated core made of stelloy, alloy of steel c) using alloys like mumetal and silicon steel d) using thick wires with considerable low resistance 39.The capacitance of capacitor which offers 1 k reactance to an AC of frequency 50 Hz is a) 3.182 x 10-6휇F b) 3.185휇F c) 3.14 10-6 F d) 3.14 x 106 F 40. Find the self-inductance of a coil when 10 A current flows through it produces the magnetic flux 0.8 weber. a) 8H b) 12.5H c) 8 x 10-2 H d) 800H 41. The power loss of a transformer having efficiency 60% and output power 2400 W is a) 4000W b) 3200 W c) 800 W d) 1600 W 42. A step up transformer converts 220 V into 1100 V. If its output power is 1650 W then the value the input current is a) 1.5 A b) 0.15A c) 7.5A d) 0.75A 43. A solenoid of air core is having 20 cm diameter, 50 cm long and 1000 turns. the magnetic flux produced when 5A current flows through it is a) 4휋2 x 10-2 weber b) 8휋2 x 10-5 weber c) 15.7 x 10-3 weber d) 31.4 x 10-2 weber 44. When a bar magnet is moving towards a coil, then the deflection in the galvanometer connected with the coil a) will be high b) is momentary c) lasts as long as magnet moves d) none of these 45. The coefficient of mutual induction between two coils is 4 H. When a current 2A flows through one coil becomes zero at 4 x 10-2 seconds then the emf induced in the other coil is a) 200 V b) 8 x 10-2 V c) 2 x 10-2 V d) 32 x 10-2 V 46.The reactance offered by a capacitor to the frequency of alternating emf


is a) Zero b) inversely proportional to the frequency c) Infinity d) directly proportional to the frequency 47. The unit equivalent to the unit Volt a) Wb. A/s b) Henry/Ampere c) Wb/s d) Tesla m-2/s 48. The current induced in a metal plate when it is oscillating in a non – uniform magnetic field a) alternating current b) direct current c) eddy current d) photo-electric current 49. In a transformer the ratio of primary voltage to secondary voltage is 2 :5. Its efficiency is 80%. Find the ratio of primary current to secondary current a) 25 : 8 b) 8 : 25 c) 100 : 4 d) 4 : 10 50. The impendence of the RLC series circuit with R= 15 ; XL = 5 and Xc = 5 at resonance of a) 15 b) 25 c) 375 d) 150 51. In a step up transformer the turns ratio is 100 : 1 when the current flowing in the primary coil is 5 A, the current in the secondary coil is a) 5.50 A b) 500 A c) 0.05 A d) 4.95 A 52. A magnetic field of induction 0.6 T flows through a coil of 200 turns and 0.02 sq.m of area of cross section reduces to 0.2 T in 0.02s. Then the emf induced in it is a) 120 V b) 240 V c ) 80 V d) 300 V 53.Direction of eddy current is given by a) Faraday’s law b) Lenz’s law c) Biot – Savart law d) Flemming’s right hand rule 54.If the secondary and primary voltages are 220 V and 11 V respectively then the transformer ratio is a) 2420 b) 20 c) 0.05 d) 4 55.The coil of area 0.1m2 with 50 turns is placed such that its plane is parallel to a uniform magnetic field 0.5 T. the flux through the coil a) 2.5Wb b) 25 Wb c) 0.25Wb d) zero 56.The power over a complete cycle in a resistive AC circuit where V = 200 V and 1 = 5 A is a) 1000 W b) 50 W c) 2000 W d) 0.025 W 57.The armature of an AC generator rotates with a speed of 3600 rpm. The


frequency of AC generator is a) 50 Hz b) 60Hz c) 100Hz d) 36 Hz 58.The peak value of an alternating current of 10 A is a) 10 A b) 1.414 A c) 14.14 A d) 7.07 A 59. If the peak value is 50V, then RMS value of voltage will be a) 30 V b) 70.7 V c) 35.35 V d) 7.07 V 60.The transformer ratio for which primary and secondary currents are 5 A and 2 A respectively is a) 2.5 b) 0.4 c) 10 d) 7 61. The ratio of peak value to rms value is a) 1.732 b) √5 c) 1.414 d) √7 62. The magnetic flux () linked with coil is related to its area (A) as a) ∝ A2 b) ∝ A c) ∝ A1/2 d) ∝ A1/2

63. An emf e = 100 sin 200 휋t is connected across a resistance of 500. The phase difference between current and voltage is a) 0° b) 90° c) 180° d) 60° 64. A transformer a) transfers energy b) transfers frequency c) transfers electric power d) generates emf 65. A transformer changes a) electrical energy b) frequency c) voltage d) emf 66. When an electric device X is connected to an ac voltage the current through it is in the same phase as the applied voltage. What is X? a) a capacitor b) a resistor c) a inductor d) a conductor 67. A transformer is used to light a 100 W, 110 V lamp from a 220 V supply, if the supplied current is 0.5 A, the efficiency of the transformer is a) 30% b) 50% c) 80% d) 90% 68. A generator produces an emf given by e = 141 sin 88 t. The frequency and rms value of voltage are a) 50 Hz and 99.7 V b) 7 Hz and 49.5 V c) 14 Hz and 99.7 V d) 50 Hz and 49.5 V 69. An ideal transformer has a power input of 10 KW. The secondary current is 25 A. If the ratio of number of turns in the primary and the secondary coils is 5 : 1, then the potential difference applied to the


primary is a) 100 V b) 200 V c) 2000 V d) 1500 V 70. If an LCR circuit, XL = 500, XC = 326.8, and R= 100 then a) 60° b) 30° c) 45° d) 90° 71.The co-effcient of Mutual inductance of a pair of coil is 4mH. If the current in one of the coils changes from 0.6 A to 0.61 A in 0.02 seconds, then induced emf is a) 2 휇V in the same coil b) 2 mV in the other coil c) 2 휇V in the other coil d) 2 mV in the same coil 72. AC frequency of 100 kHz to 100 MHz is required for a) satellite purpose b) domestic purpose c) transmission of audio and video signals d) high transmission 73. Power dissipation on an AC circuit in which voltage and current are given by e = 300 sin (휔t + 휋/2) and I = 6 sin 휔t is a) 0 watt b) 750 watt c) 375 watt d) 1500 watt 74. A circuit will have flat resonance, if the Q value is a) high b) infinity c) low d) zero 75. 400 MW power produced at 15,000 V at power station is stepped up to ……..before transmission. a) 22,000 V b) 2,30,000 V c) 110, 000 V d) 20, 000 V 76.Whenever a magnet is moved either towards or away from a coil, and induced emf is generated, the magnitude of which is independent of a) the strength of the field b) the number of turns in the coil c) the speed with which the magnet is moved d) the size of the magnet 77. A coil is connected to a source of emf through a tap key. Then emf is induced a) only during closing the tap key b) both during closing and opening the tap key c) Only during opening the tap key d)only when passing a steady current 78. The induced current flowing in a coil due to the decrease of magnetic flux from 1 Wb to 0.1 Wb in 0.1 s is 90mA, the resistance of the coil is a) 1 K b) 100 c) 10 d) 1 79. To change the frequency of induced emf in an ac generator must be changed a) number of turns in armature b) area of armature c) magnetic induction d) speed of rotation of armature 80. With respect to magnetic field, the axis of rotation of armature is


a) parallel b) making an angle 45° c) perpendicular d) making an angle of 180° 81. A 400 KW power is supplied through a transmission wire of resistance 0.75 . if the power loss is 300 W, at what p.d. the transmission should take place? a) 10 kV b) 20 kV c) 30 kV d) 40 kV 82. The peak value of emf induced in a coil of cross – section 0.025m2 with 20 turns when it is rotated uniformly at 600 rpm in a magnetic field of 10 T is a) 220 V b) 314 V c) 222 V d) 300 V 83. A coil of area 500cm2 with 1000 turns is rotated through 180° in 1/10s. If the emf induced is 90mV, the magnetic field is a) 0.9 T b) 0.9 x 10-2 T c) 0.9 x 10-3 T d) 0.9 x 10-4 T 84. When an inductor is connected to an a.c circuit in series, the reactance of the circuit is a) increased b) unchanged c) decreased d) zero 85. In radio receivers, the circuit is tuned to the frequency of desired signal by varying a) resistance b) inductance c) capacitance d) either of there 86. The polarity of AC voltage of frequency 50Hz is reversed in 1s by a) 50 times b) 100 times c) 150 times d) 200 times 87. In an LCR series ac circuit with the supply of 100 V, 50 Hz if the inductive reactance, capacitive reactance and resistance respectively are 10, 7 and 4 the impedance is a) 5 b) 10 c) 15 d) 20 88. An inductor coil is connected to 220 V, 50 Hz supply. If the peak value of currents 2.2A, the inductive reactance a) 141.4 b) 70.7 c) 282.8 d) 35.35 89. In an LCR circuit with impedance of 5, if the reactance is 3, the resistance should be a) 2 b) 4 c) 6 d) 8 90. Quality factor of a resonant circuit determines a) impedance at resonance b) current at resonance c) selectivity or sharpness of the circuit d) each of these 91. In an AC circuit, the current and emf are represented by


I = I0 sin (wt – 휋/3) and e = Eo sin (wt + 휋/2). Here voltage leads the current by a phase angle of a) b) c) 5 d) 3 92.The angular velocity of the armature rotating with a speed of 300/2 turns per minute in an ac generator is a) 5 radian/s b) 15 radian/s c) 22.5 radian /s d) 10 radian 93.In a long solenoid , when its length and number of turns are doubled then its self inductance is a) halved b) double c) remains same d)increased four times 94.The working of the transformer is based on the principle of law of conservation of a) charges b) energy c) momentum d) mass 95.If the metallic plate with holes drilled in it is made to swing inside the magnetic field a) the speed of oscillation could not be damped b) the speed of oscillation increases c)the eddy current rapidly increases d) the speed of oscillation decreases 96.If the metallic plate with holes drilled in it is made to swing inside the magnetic field a) the eddy current is greatly reduced b) the speed of oscillation increases c)the eddy current rapidly increases d) the speed of oscillation decreases 97.The copper loss in a transformer can be reduced by using a) thin wires having low resistance b) thin wires having high resistance c) thick wire of considerably low resistance d) thick wires of high resistance 98.The input power of a transformer is 50 W its output power is 20W. Then its efficiency is a) 20% b) 50% c) 70% d) 40% 99.When an AC current of 50Hz frequency flows through a coil it offers a reactance 942 , than the self inductance of the coil is a) 314H b) 3H c) 18.8H d)12.5H 100.A capacitor of capacitance 50F offers a reactance 31.84 for an AC , then the frequency of AC is a) 100Hz b) 50Hz c) 25Hz d) 5 Hz


101.The resonance frequency of L,C & R resonance circuit containing 4H inductance and 25/2 F capacitance is a) 100Hz b) 220Hz c) 25Hz d) 50Hz 102.The angle between the area vector A and the plane of the area A is a) b) 2 c) /2 d) zero 103.If N=1,(l=2m), I=0.5A, A=4m2, find the magnetic flux per turn of the coil. a)20 b) 40 c) 1/2 0 d) 0 104.Find the total magnetic flux when N=2,A=4m2, I= 1Aand l=2m a)20 b) 40 c) 16 0 d) 80 105.If the flux associated with a coil varies at the rate of 1Wb/minute then the induced emf is a)1V b) 0.2V c) 0.1V d) 0.017V 106.The self inductance of a coil is a) directly proportional to N b) inversely proportional to N c) directly proportional to N2 d) inversely proportional to N2 107.The coefficient of self-induction of a solenoid is independent of a) the number of turns in coil b) the area of cross section of the coil c) the length of the coil d) the current passing through the coil 108.Energy or work done is stored in an inductor as a) electrical energy b) magnetic potential energy c) electrical potential energy d) heat energy 109.Which of the following set of two coils will have the maximum coefficient of mutual induction? a)placed perpendicular to each other b) placed parallel to each other c) placed side by side d) wound on a soft iron core. 110.Find the coefficient of mutual induction of a solenoid having N1=N2= 3, l=6m and A=9 m2 a) 5 /3 b) 27 /2 c) 2/27 d) 18/7 111.If the flux associated with a coil varies at the rate of 1Wb/ min. Then the induced emf is a) 1V b) 1/60 V c) 60V d) 0.60V 112.The emf induced in a coil is maximum when t is a) 0 b) / 2 c) d) 2 113.The angle between the induced current in a circuit and the change that produces it is equal to


a) 00 b) 900 c) 450 d) 1800 114.If N=1 and l=1m, magnetic field , B is a) 2I b) 0I c) 0/I d) 4I/3 115.While emf is induced by changing the orientation of the coil, the induced emf is a …….function of time a) linear b) non-linear c) decay d) sinusoidal 116.In an a.c. generator , the induced current in the external circuit keeps changing its direction for every….. rotation of the coil a) one b) half c) two- third d) one –fourth 117.An alternator produces voltage waves equal to the number of….. used. a) slip rings b) winding c) magnets d)brushes 118.The alternators are widely preferred for transmitting large amount of power with less cost and high efficiency is a) single phase b) two phase c) three phase d) poly phase 119.The emf induced in each of the coil of a 3- phase alternator is separated with a phase difference of a) 900 b) 1200 c) 600 d) 2700 120.In a three phase AC generator , current in the three coils differ in phase by a) 0 b) /2 c) d) 2/3 121.A solid metal mass moving in a non-uniform magnetic field produces a) ac current b) dc current c) eddy current d) either ac or dc current 122.The direction of eddy currents is given by a) Faraday’s law b)Lenz’s law c)Joule’s law d)Ampere’s circuital law 123.Eddy currents produces…… in an induction furnace. a) high temperature b) magnetic flux c) induced emf d) high voltage 124.Electromagnetic damping is produced in the deadbeat galvanometer by a) ac current b) ac voltage c) eddy current d) dc current 125.The galvanometer whose coil is wound on a metallic frame is called….. galvanometer a) light b) heavy c) dead beat d) oscillatory 126The eddy current in an induction motor, initially tries to …. the relative motion between the cylinder and the rotating magnetic field a) increases b) decreases c) equalize d) nullify 127.Induction motors are used in


a) TV sets b) radio c) fans d) lights 128.The efficiency of an ideal transformer is a) 0 b) 1 c) infinite d) none 129.In electric power transmission , the wastage of power is a) more at high voltage b) independent of voltage c) more at low voltage d) low at low voltage 130.The quantity that changes with time in an AC current is a) magnitude b) direction c) both magnitude and direction d) none 131.The average value of AC quantity for one complete cycle is a) zerob) one c) infinite d) small 132.The rms value of the alternating current(AC)flowing through a resistor is 5A . Its peak value is a)3.536A b) 70.7A c) 7.07A d) 7A 133.The rms value of an ac voltage with a peak value of 311 V is a) 100V b) 220V c) 50 V d) 70.7V 134.The voltage drop across the resistor in a LCR series circuit has phase difference of …. with the current (I) a) /2 b) c) 0 d) /4 135.In order to avoid wastage of power due to Joule’s heating effect through a resistor, we use a) a pure inductor b) a capacitor c) photo-resistors d) thermistors 136.If Z=R in a series RLC circuit a) L =1/C b) L =1/ C c) L =C d) C = L 137.In LCR series AC circuit , the phase difference between current and voltage is 300 . The reactance of the circuit is 17.32.The value of resistance is a) 30 b) 10 c) 17.32 d) 1.732 138.If R=2k, XL = 5k , XC = 2.3k , V=6V, the maximum current through a LCR circuit at resonance is a) 5A b) 3.9mA c) 3mA d) 2.7mA 139.In case of zero phase difference between the emf and the current in an AC circuit, its average power is a) 0 b) E0 I0/ 2 c) Erms Irms /2 d) E0 I0/ 4 140.A choke is a) a resistor b) a capacitor c) an inductance coil d) an LED 141.Chokes used in low frequency AC circuits are called ….chokes.


a) UV b) RF c) AF d) HF 142. Chokes used in high frequency AC circuits are called ….chokes. a) AF b) RF c) TF d) UF 143.The average power consumed by a choke coil over a complete cycle is a) E0 I0/ 2 b) 0 c) 1 d) Erms Irms 144.Chokes used in low frequency AC circuits have …. core a) copper b) air c) dielectric d) iron 145.The core used in audio frequency chokes is a) iron b) carbon c) lead d) air 146.If in an LCR circuit XL = 500 , XC = 326.8, R =100, then is a) 600 b) 300 c) 450 d) 900 147.At what rate must the current changes in a 65 mH coil to have a 1V self induced emf? a) 25 As-1 b) 17 As-1 c) 25.4 As-1 d) 15.4 As-1 148.The equation of a 25 cycle current sine wave having rms value of 30 A is a) 30 sin 157t b) 30sin150t c) 302sin157t d) 30sin160t 149.How much current is drawn by the primary of an ideal transformer connected to a 220V supply. When it delivers power to a 110V and 550W refrigerator? a) 55A b) 2.5A c) 0.4A d) 44A 150.The average power of an AC is also called …. of the circuit a) true power b) transtaneous power c) resonant power d) rms power 151.The product of magnetic flux density and area is a) electromagnetic induction b) electromagnetic force c) magnetic flux d) magnetic induction 152.In a step down transformer , the following connection is satisfied a) ES EP b) K1 c) IP IS d) NP NS 153.A wire cuts across a flux of 0.2x10-2W in 0.12s.What is the emf induced in the wire. a) 0.06V b) 0.02V c) 0.0167V d) 0.24V 154.In a step-down transformer ,the input voltage is 22KV and the output voltage is 550V. The ratio of number of turns in the primary to that in the secondary is a) 1:40 b) 40:1 c) 1:20 d) 20:1 155.Low frequency AC can be blocked with the help of


a) capacitor b) inductor c) resistor d) choke coil 156. An emf of 12 V is induced when the current in the coil changes from 2 A to 6 A in 0.5 s. The coefficient self induction of the coil is a) 1.5 H b) 6 H c) 0.3 H d) 30 H 157. In an AC circuit average power consumed is 200W and the apparent power is 300W. The power factor is a) 1.5 b) 0.66 c)0.33 d)1 158.In a series LCR circuit ,at resonance a) XL=XC b) XLXC c) XLXC d) = 1/LC 159. In an AC circuit, a resistance of R ohm is connected in series with an inductance L. If phase angle between voltage and current is 45o the value of inductive reactance is a) R b) 2R c)R/2 d) R/4 160.When the frequency of an AC circuit increases , the capacitive reactance offered by capacitor connected in the circuit a) increases b) decreases c) remains same d) becomes zero 161.A rectangular coil is uniformly rotated in a uniform magnetic field such that the axis of rotation is perpendicular to the direction of the magnetic field. When the plane of the coil is perpendicular to the magnetic field. a) (i)magnetic flux is zero, (ii) induced emf is zero b)(i) magnetic flux is maximum (ii) induced emf is maximum c) (i) magnetic flux is maximum (ii) induced emf is zero d) (i) magnetic flux is zero (ii) induced emf is maximum. 162.In AC circuit , the voltage leads the current by a phase of /2, then the circuit has a) only an inductor(L) b) only a capacitor(C) c) only a resistor (R) d) L,C and R in series. 163.The resonant frequency of RLC circuit is 0. The inductance is doubled and the capacitance is also doubled. Now the resonant frequency of the circuit is a) 2 0 b) 0/2 c) 0/4 d) 0/ 2 164.The ratio between peak current and effective current is a) 0 b)2 c)1.414 d) 0.707


165.The number of turns in a solenoid of length l is N. The self inductance of the solenoid is proportional to a) N / l b) N2/ l c) N l d) N2l 166.The reactance offered by a capacitor to an AC is X. When the capacitance is doubled , the reactance is a) 2X b) X c) X/2 d) X/4 167.A fuse is having rms value of current rating of 10A. Then the peak value of the fuse wire is a) 7A b) 1A c) 707A d) 7.07A 168.The rms value of AC is …… times the peak value of AC a) 70.7% b) 1/2 c) 0.707 d) all 169.Q- factor of a circuit can be increased by having a coil of a) large inductance and high current b) large inductance and low resistance c) small inductance and high resistance d) small inductance and low reactance 170.Coefficient of self inductor of solenoid is independent of a) number of turns in coil b) the area of cross section of coil c) the length of the coil d) the current passing through the coil. 171.A current of 1A flowing through a coil of inductance 1H is switched off in 1 millisecond. What is induced emf. a) + 100V b) 100V c) + 1000V d) 1000V 172.A conductor moving in the magnetic field B the induced current is I. If the magnetic field is doubled, the induced current will a) remain same b) be half c) be double d) be four times 173.The self inductance of a straight conductor is a) Zero b) infinity c) very large d) very small 174.The induced emf is maximum in a coil when the plane of the coil is ……… to B. a) at right angles b) acute angles c) parallel d) not parallel 175.The number of magnetic lines of force crossing unit area normally is a) magnetic flux b) magnetic induction c) induced emf d) total flux 176.Weber per ampere can be written as a) farad b) coloumb c) henry d) volt


177.Energy is stored in an inductor as a) electrical energy b) electrical potential energy c) magnetic potential energy d) neither electric nor magnetic energy 178.Total number of magnetic lines of force linked with the area of cross section of a coil is known as a) magnetic flux b) magnetic flux density c) magnetic permeability d) magnetic intensity 179.The strength of current produced in a generator is a) directly proportional to the speed of revolution of armatures b) inversely proportional to the speed of revolution of armature c) inversely proportional to the magnetic field d) inversely proportional to the area of coil 180.When the voltage is greater and current is less, the power wasted in transmission line is a) more b) less c) 0 d) infinite 181.In a step-up transformer induced voltage in primary is 220V and secondary induced voltage is 11kv. The ratio of number of turns in secondary to that in primary is a) 20 : 1 b) 22 : 1 c) 1 : 50 d) 50 : 1 182.A d.c circuit contains 10Ω resistance in series with 10H coil. The impedance of the circuit is a) 10 Ω b) 20 Ω c) 1 Ω d) zero 183.Resonance frequency of a circuit is f. If the capacitance is made 4 times the initial value, then the resonance frequency will become a) f b) 2f c) f/2 d) f/4 184.Eddy currents are produced, when ……… a) a metal is kept in varying magnetic field b) a metal is kept in steady magnetic field c) a circular coil is placed in magnetic field d) all the above 185.The rms value of an altlernating current is ………. a) less than zero b) equal to its peak value c) less than its peak value d) greater than its peak value 186.A transformer ……….. a) changes energy b) changes frequency c) changes voltage d) generates emf


187.The average value of alternating current over one complete cycle is a) Io b) Io/2 c) 2 Io d) zero 188.At resonance, the impedance of the AC circuit is …….. a) inductive b) capacitive c) resistive d) combination of inductive and capacitive reactance’s 189.At resonance frequency in an LCR circuit the potential drop across LC combination is a)maximum b)minimum c) first increases and then decreases d) zero 190.At resonance VL and VC are a) in phase b) out of phase by c)out of phase by /2 d) out of phase by 270 0 191.According to Faraday’s law of electromagnetic induction a) an emf can be produced by time varying magnetic flux b) a magnetic field is produced by time varying electric field c) the charge is conserved d) the magnetic field associated with the conductor is equal to the flux 192.When a varying current flows through a coil, an emf is induced in it. This is a) motor action b) generator action c) known as self induction d) known as mutual induction 193.When the coil in an AC generator rotates at an angular velocity of 50π rad/s, the frequency of the induced emf a) 100 Hz b) 50 Hz c) 25 Hz d) 1000 Hz 194.The power factor of an AC in LCR series circuit at resonance is a) zero b) one c)less than one d) greater than one 195.A dc of 5 A produces the same heating effect as an AC of a) 50 A rms current b) 5 A peak current c) 5 A rms current d) 50 A peak current 196.In a resonant circuit at resonance a) the current is minimum b) the impedance is maximum c) the voltage and current are in phase d) the voltage and current are in out of phase 197.The current in the LCR series circuit is maximum when a) the inductive and capacitive values are numerically equal b) the inductive and capacitive reactance are equal c) the inductive reactance and resistance are equal


d) the capacitive reactance and resistance are equal 198.At resonant frequency in an LCR circuit the potential drop across LC combination is a) maximum b) minimum c) zero d) first increases and then decreases 199.The orientation of a coil is at zero degree if it is ….. to the magnetic field a) parallel b) neither parallel nor perpendicular c) either parallel or perpendicular d) perpendicular 200.When a coil is rotated in a magnetic field with constant speed, then a) a periodic emf is induced b) emf is not induced c) unidirectional emf is induced d) rectification occurs II. IMPORTANT UNITS

1.The unit of self inductance is ……… 2.Henry is equal to ………… 3.The unit of inductive reactance is ……….. 4.The unit of capacitive reactance is ………. 5.The unit of impedance is ……….. 6.The unit of frequency is ………. 7.The unit of induced emf is 8.The unit of mutual inductance is …… 9.The unit of magnetic flux is ……… 10.The unit of magnetic field is ……. 11.The unit of inductance is …….. 12. The unit of capacitance is ……. 13.The unit of resistance is …….. 14.The unit of power dissipated is ……. 15.The unit of energy stored in the inductor is …… III. STANDARD VALUES 1.The permittivity of free space is ……. 2.The self inductance of a straight conductor is ………. 3.In three phase AC generator , the three coils differs in phase by …….. 4.Domestic power in India is supplied at a frequency of ……..


5.RMS value of AC is ….. % of the peak value . 6.Inductive reactance for direct current is ……… 7.Capacitive reactance for direct current is ……… 8.Voltage drop across inductor and capacitor differs in phase by ……. 9.Q-factor has value lying between …….. to …….. for normal frequencies. IV. IMPORTANT FORMULAE 1.Magnetic flux is ………. 2.Magnetic flux over the closed area in vector form is …… 3.According to Faraday’s law of electromagnetic induction the induced emf is …….. 4.According to Faraday’s law and Lenz’s law the induced emf is …. 5.Induced emf by changing the magnetic induction is ……… 6.Induced emf by changing the area enclosed by the coil is ……… 7.Induced emf by changing the orientation magnetic induction is …… 8.The induced emf across an inductor is ……… 9.The magnetic flux linked with a current carrying coil is ……… 10.The coefficient of self induction of a solenoid is ………. 11.Energy stored in a inductor (coil) is ……… 12.Coefficient of mutual inductance is ………. 13.Mutual induction between two long solenoid is …….. 14.Transformer formula is ……… 15Transformer ratio is ……….. 16.Efficiency of a transformer ………. 17.Power loss is………….. 18.RMS value of AC current is ……… 19. RMS value of AC voltage is ……… 20.Expression for instantaneous value of voltage is ………. 21. Expression for instantaneous value of current is ………. 22.Inductive reactance is …….. 23.Capacitive reactance is …….. 24.Impedance in LCR circuit is ………. 25.Resultant voltage in LCR circuit is………. 26.Phase angle between the voltage and current in LCR circuit is ……. 27. Resonant frequency of the series LCR circuit is ……… 28.Average power consumed by the choke coil is ……… 29.Q factor of a series resonance circuit is ………..


V.THREE MARK QUESTIONS I. DEFINATIONS: 1. Define magnetic flux. 2. Define coefficient of self inductance. 3. Define coefficient of mutual inductance. 4. Define henry. 5. Define rms value of AC. 6. Define alternating current and give its expression. 7. Define power factor. 8. Define quality factor. 9. Define efficiency of transformer. 10. Define inductive reactance. 11. Define capacitive reactance. 12. Define resonant frequency. II. LAWS AND PRINCIPLES

13. State electromagnetic induction. 14. State Faraday’s laws of electromagnetic induction. 15. State Lenz’s law. 16. State Fleming’s right hand rule. III.USES.(APPLICATIONS)

17. Give the uses of choke coil. 18. Give the uses of transformer. VI.REASONING QUESTIONS

19. Why a DC ammeter cannot read AC? 20. A capacitor blocks d.c. but allows a.c. .Explain 21. Can a transformer be used for stepping up DC? Explain. 22. Why the efficiency of a transformer is always less than unity? VII.DISTINGUISHING AND DIFFERENTIATING QUESTIONS

23. Differentiate between self inductance and mutual inductance. 24. Mention the difference between a step up and step down transformer. 25. Differentiate between AF choke and RF choke. 26. Differentiate between inductive reactance and capacitive reactance. VIII.THEORY QUESTIONS


27. State the methods of producing induced emf. 28. What is a poly phase AC generator? 29. What is eddy current? How will you reduce eddy current? 30.What is choke coil? 31. On what factors does the coefficient of mutual induction depend on? VI. THREE MARK PROBLEMS 1.A coil of 20 turns and area 10-4 m2 placed perpendicular to a magnetic field of induction 5 x 10-3 Wb / m2 . Calculate the magnetic flux through the coil. 2.In a magnetic field , magnetic flux is 10 Wb, the magnetic flux density is 0.1NA-1m-1 and the flux lines are perpendicular to the area . What is the area of the magnetic flux? 3.The self induction of a coil is 5 mH and an electric current of 10 A is flowing through it. Calculate the induced emf in the coil if the current is reduced to zero from 10 A in 0.2 s. 4 .A coil has self inductance of 0.02 H. Calculate the value of induced emf when the current in the coil is changing at the rate of 150As-1 5.When 0.5 A current passes through an inductor coil, the flux linked with it is 0.15 Wb. Then find the self inductance of the coil . 6.Two coils of inductance 2 H and 3 H are connected in series Find the effective inductance . 7.Two coils of inductance 2 H and 3H are connected in parallel. Find the effective. 8. A current of 4 A passing through a coil is cut off in 10-3s . Another coil has a mutual induction of 40 mH with the first one. Calculate the emf induced in the second coil. 9.An emf of 60 mV is induced in a coil when current in neighbouring coil changes from 11 A to 5 A in 0.10 second. Calculate their coefficient of mutual inductance. 10.A coil of 1000 turns and area 0.02 m2 is placed normal to a uniform magnetic field of induction 0.4 Wb/m2.Calculate the magnetic flux through the coil . 11.A coil having 100 turns and a cross sectional area of 0.03 m2 in a magnetic field which changes from 0.20 Wb/ m2 to 0.40 Wb /m2 at a uniform rate over a period of 0.03 sec. What is the magnitude of the


induced emf in the coil? 12.A helicopter rises vertically with a speed of 36 km / hr. If the helicopter be a horizontal linear conductor of length 10 m and if the horizontal component of the earth’s magnetic induction be 2 x10-3 tesla, Then find the potential difference between the tips of the nose and tail of the helicopter. 13.If a straight conductor of length l and of resistance R is moving perpendicular to a uniform magnetic field of flux density B with a velocity v then find the induced current. 14.A wire of length 50 cm moves with a velocity of 300 m/min perpendicular to a magnetic field. If the emf induced in the wire is 2 V Find the magnetic induction 15.When the coil in an AC generator rotates at an angular velocity of 50 rad /s . Calculate the frequency of the induced emf . 16.A current of 5 A flows through a conductor of resistance 3 . What is the loss of power due to joule’s heating effect? 17.A transformer steps up 220 V to 2200 V. If the secondary coil of the transformer has 200 turns, Calculate the number of turns in the primary. 18.In a step up transformer, the input voltage is 220 V and the output voltage is 11 kV. Then find the ratio of the number of turns of secondary to primary . 19.Calculate the current drawn by the primary coil of a step down transformer which steps down 220 V to 22 V with an output power of 22W. 20.An ideal transformer has 50 turns on its primary and 250 turns on the secondary. If at 12 V, 4 A current is passed through the primary, find the current in the secondary. 21.A voltage rating of 220 V alternating current. Calculate the peak value of incoming sinusoidal voltage . 22.A fuse having a current rating of 6 A. Calculate the peak value of current flowing through it. 23.An alternating voltage is represented by e=100 sin 314 t. Calculate its rms value . 24.The peak values of voltage and current in a circuit containing resistor only are 240 V and 0.5 A respectively. Calculate the power. 25.Calculate the reactance offered by a 3 H inductor to an AC supply of frequency 50 Hz.


26.When 100 V AC of frequency 50 Hz is applied to a coil, a current of 0.5 A flows through it. What is the impedance of it? 27.Calculate the frequency at which a 2 H inductor has a reactance of 20 to an AC circuit with the inductor only. 28.Calculate the reactance of a capacitor of 1 / farad and 50 Hz is. 29.An AC circuit contains 4 resistance in series with an inductance coil of reactance 3. Calculate the impedance of the circuit. 30.Calculate the resonant frequency 0 of a series RLC circuit with L= 2H, C = 32 F. 31.The capacitive reactance of a 15 F capacitor at a frequency of 2000 Hz is 6.28 . Then calculate the inductance required to produce resonance 32.Calculate the reactance offered by a 1 henry inductor to an AC of frequency 50 Hz . 33.How much magnetic potential energy is stored in a 20 mH coil carries a current of 0.2 A? 34.Calculate the value of capacitance which offers a reactance of 1000 ohm to an AC supply frequency of 50 Hz. 35.Calculate the value of inductance which offers a reactance of 628 ohm to an AC supply of frequency 50 Hz. 36.Calculate the inductive reactance of a coil , if the current through it is 30 mA when the p.d. across it is 60 V. 37.The co-efficient of mutual inductance is 5H between the primary and secondary of a coil. A current of 10A is cut off in 5 second. Calculate the induced emf. 38.Calculate the frequency at which a 1 henry inductor has a reactance of 314 ohm VII.SHORT ANSWER (5 MARK QUESTIONS) 1.State Lenz’s law and explain how is it in accordance with the law of conservation of energy. 2.Explain how an emf can induced by changing the area enclosed by the coil. 3.Obtain an expression for energy associated with an inductor. 4.Explain the principle , construction and working of a choke coil.


5.Explain varies losses in a transformer. How can these be minimized . 6.Derive an expression for Q-factor and explain variation of current with frequency. 7.Obtain an expression for the rms value of AC. 8.Obtain an expression for the current flowing in a circuit containing resistance only to which alternating emf is applied. Find the phase relationship between voltage and current. 9.Obtain an expression for the current flowing in a circuit containing inductance only to which alternating emf is applied. Find the phase relationship between voltage and current 10.Obtain an expression for the current flowing in a circuit containing capacitance only to which alternating emf is applied. Find the phase relationship between voltage and current 11.Derive an expression for the average power in an AC circuit. 12.Explain self induction. Deduce the unit for self inductance. 13.Explain the phenomenon of mutual induction and calculate the coefficient of mutual induction. 14.Explain the mutual induction between two long solenoids. Obtain an expression for the mutual inductance. VIII.TEN MARK QUESTIONS 1.Discuss with theory the method of inducing emf in a coil by changing its orientation with respect to the direction of the magnetic field. 2.Describe the principle ,construction and working of a single –phase AC generator. 3.Explain the principle of transformer. Discuss its construction and working. 4.A source of alternating emf is connected to a series combination of a resistor R, an inductor L and a capacitor C. Obtain with the help of a vector diagram and impedance diagram, an expression for (i) the effective voltage (ii) the impedance (iii) the phase relationship between the current and the voltage. 5.What are eddy currents? Explain their applications. How are they minimized?


KEY-4 LESSON 1 d 21 a 41 d 61 c 81 b 101 d 121 c 141 c 161 c 181 d 2 b 22 a 42 c 62 b 82 b 102 c 122 b 142 b 162 a 182 a 3 b 23 d 43 a 63 a 83 d 103 d 123 a 143 b 163 b 183 c 4 c 24 c 44 b 64 c 84 a 104 d 124 c 144 d 164 c 184 a 5 a 25 b 45 a 65 c 85 c 105 d 125 c 145 a 165 b 185 c 6 b 26 d 46 b 66 b 86 b 106 c 126 b 146 a 166 c 186 c 7 c 27 c 47 c 67 d 87 a 107 d 127 c 147 d 167 d 187 d 8 b 28 a 48 c 68 c 88 a 108 b 128 b 148 c 168 d 188 c 9 d 29 d 49 a 69 c 89 b 109 d 129 c 149 b 169 b 189 d 10 a 30 b 50 a 70 a 90 c 110 b 130 c 150 a 170 d 190 b 11 d 31 c 51 c 71 b 91 c 111 b 131 a 151 d 171 d 191 a 12 c 32 c 52 c 72 c 92 a 112 b 132 c 152 b 172 c 192 c 13 c 33 b 53 b 73 a 93 b 113 d 133 b 153 c 173 a 193 c 14 d 34 c 54 b 74 c 94 b 114 b 134 c 154 b 174 c 194 b 15 c 35 b 55 d 75 b 95 a 115 d 135 c 155 a 175 b 195 c 16 c 36 a 56 a 76 d 96 a 116 b 136 b 156 a 176 c 196 c 17 b 37 c 57 b 77 b 97 c 117 b 137 a 157 b 177 c 197 b 18 a 38 b 58 c 78 b 98 d 118 c 138 c 158 a 178 a 198 c


19 b 39 b 59 c 79 d 99 b 119 b 139 b 159 a 179 a 199 d 20 b 40 c 60 a 80 c 100 a 120 d 140 c 160 b 180 b 200 a

5.ELCTROMAGNETIC WAVES AND WAVE OPTICS 1.The angle between electric field and magnetic fields occur simultaneously in the perpendicular plans and attain their maxima and minima at a) 0.1 second between the field b) 1 second between the fields c) 10 second between the fields d) the same time 2.The angle between electric and magnetic fields in electromagnetic waves is a)00 b) c) /2 d) 2 3.What is the phase difference between electric and magnetic field vectors in the electromagnetic waves? a) 00 b) c) /2 d) 2 4.The velocity of light is maximum in a)diamond b) water c) vacuum d) glass 5.If Vg, Vx and Vm are the speed of gamma rays, X-rays and microwaves respectively in vacuum , then a) Vg Vx Vm b) Vg Vx Vm c) Vg Vx Vm d) Vg= Vx = Vm 6.The wavelength of microwave is a) smaller than the wavelength of violet light b) smaller than the wavelength of yellow light


c) larger than the wavelength of red light d) larger than the wavelength of radio waves 7.A red flower seen in the light of mercury vapour lamp through a green filter will appear a) black b) red c)violet d) white 8.The amount of bending of light depends upon the a) wavelength b) frequency c) intensity d) phase 9.The phenomenon responsible for the colour of the sky is a) scattering b) refraction c) reflection d) dispersion 10.The blue colour of the sky is due to the scattering of …… of the sun rays a) shorter wavelength b) longer wavelength c) all the wavelength d) none of the above 11.The Raman lines having frequencies lower than the incident frequency called a) unmodified lines b) Stoke’s lines c) Anti-Stoke’s lines d)absorption lines 12.The waves are diffracted only a) at higher wavelength b) at lower wavelength d) at high speed c)when the size of the obstacle is comparable to wavelength 13. When light passes from one medium into another medium, then the physical property which does not change is a) velocity b) wavelength c) frequency d) refractive index 14.The refractive index is directly proportional to a) b) 2 c) 1/2 d) 1/ 15.In interference pattern , the width of the dark fringes 1 the width of the bright fringe 2 is a) 21= 2 b) 22= 1 c) 1= 2 d) 1+ 2 =1 16.What is the scattering ratio of two waves having wavelength ratio 2 :3 a) 81 : 16 b) 16 : 81 c) 81 : 64 d) 64 : 81 17.The spectrum obtained by the white light when it is allowed to pass through dilute blood a) Line emission spectrum b) Continuous absorption spectrum c) Band absorption spectrum d) Line absorption spectrum 18. According to Huygens. light wave is


a) e.m.wave b) Transverse wave c) Longitudinal wave d) Light ray photon 19.The wavelength of light is λ and rate of scattering is S. According to Rayleigh’s scattering law a) S λ1/4 b) λ S -1/4 c) S λ 4 d) λ S 4 20.The Raman frequency observed from Raman effect a) is positive for Stokes lines b) is negative for anti-Stokes lines c) does not depend on the frequency of incident light d) all the above 21.Which property of light changes when it travels from one medium to other medium. a) Frequency b) Wavelength c) Velocity d) Both (b), (c) 22.The amplitude ratio of two coherent waves is 5 : 2 Then their ratio of maximum and minimum intensities a) 25 : 4 b) 49 : 9 c) 4 : 25 d) 9 : 49 23. In Young’s experiment. When a light of wavelength 4800 A0 is used. the width of the fringe obtained is 2.4mm. Find the fringe width when a light of wavelength 5600 A0

a) 1.8 mm b) 2.8 mm c) 2.1 mm d) 2.55 mm 24. The wavelength of light in vacuum be λ a and in water medium be λ w, then refractive index of water is given by. a) = λa x λw b) = λa / λw c) = λw / λa d) = λa - λw 25. As ‘n’ increases, Newton’s rings a) get closer b) get broader c) disappear d)none of these. 26. When a light ray of wavelength 6000 Ao travels from air into a medium of refractive index 1.5 , its frequency will be a) 4 x 1014 Hz b) 7.5 x 1014 Hz c) 5 x 10 14 Hz d) 6.4 x10 14 Hz 27. In Newton’s rings. the radius of nth dark band in air is ‘rn’ and in liquid is’ m then the refractive index of liquid is given by a) = rn / rm b) = rm/ rn c) = rn

2/ rm2 d) = rm

2 /rn2

28.Diffraction effect is pronounced more in sound than in light, because a) Wavelength of sound is low b) Wavelength of light is low c) Velocity of sound is low d)Velocity of light is high 29. When a plane polarized ray is allowed to pass through an analyser, and the analyser is rotated through an angle 90° then the intensity of out coming ray a) remains the same b) changes from maximum to zero c) changes from maximum to minimum d) changes from zero to maximum 30. According to Brewster’s law


a) = tan -1 ip b) = cot ip c) ip = tan -1 () d) ) = (tan ip) 1/2 31. In Newton’s rings experiment the radius of 2nd dark ring is R. then radius of 8th dark ring is a) 2 R b) 4 R c) R/2 d) R/4 32. In double refraction crystal the extra –ordinary ray produces……… wave front. a) spherical b) plane c) cylindrical d) elliptical 33. In Newton’s rings experiment the thickness of the air film at which 4th dark ring is produced when wavelength of light used is 5000 A0 a) lm b) 20 x 10-7 m c) 8 x10-6 m d) 6.5 x 10-7 m 34.A light ray incident on a reflecting surface at an angle 53° 4’. If the reflected ray is completely plane polarized then the sum of incident angle and refracting angle is a) 106° 8’ b) 26°56’ c) 90° d) 116°56’ 35.The shape of wave front going to diffract in Fraunhofer diffraction a) Spherical b) cylindrical c) plane d) elliptical 36. In a plane transmission grating the width of slit is 300 nm and width of line is 200 nm, then ‘N’ value of grating is a) 6 x 105 line/meter b) 2 x 106 line/meter c) 1.5 x 109 line/meter d) 6.5 x 109 line/meter 37.The makers formula ‘N’ of a grating is 6000/cm then the grating element is a) 6 x 105 m b)1.66 x 10-6 m c) 2.8 x 10-5 m d) 3.5 m 38.The refractive index of water is 4/3. Then its angle of polarization is a) 52.5° b) 57.5° c) 53.4° d) 60° 39.Which of the following is an optically active substance? a) NaCl b) sugar crystals c) turpentine oil d) all of these 40.The scientists who suggested light rays are transverse a) Foucault, Huygens b) Huygens, Fresnel c) Newton, Einstein d) Fresnel, Young 41.If S1 , S2 are the rate of scattering of two light rays, then their wavelength ratio is a) λ1/ λ2 = (S1/ S2 )4 b) λ1/ λ2 = (S1/ S2 )1/4 c) λ1/ λ2 = (S1/ S2 ) d) λ1/ λ2 = (S2/ S1)1/4 42.Raman effect supports


a) Quantum theory b) Corpuscular theory c) Wave theory d) Electromagnetic theory 43.When a light ray photon is incident on an excited atom. gain some energy from it and scattered. the wavelength of scattered photon a) increases b) decreases c) does not change d) becomes zero 44.The phase difference between the successive particles of a wave front a) /2 b) c) 3/2 d) 0 45.Which property of light could not be changed when reflection, refraction of light occurs? a) velocity b) frequency c) wavelength c) all these 46.The light waves emitted by two same type monochromatic light sources could not be coherent because the light waves are not having a) same wavelength b) same amplitude c) same phase d) same frequency 47.Condition for getting sustained interference is a) the two source could be coherent b) two sources should be very narrow c) two sources should be very close to each other d) all the above 48.The colours appeared by interference due to reflection of light rays on thin film depends upon a) The thickness of the film b) density of the film material c) The angle of incidence of light d) Both (a) and (c) 49. A ray of light traveling in air and getting reflected at the surface of denser medium undergoes a phase change of a) 0 b) /2 c) d) 2 50. When a light is allowed to pass through an analyser. and rotate the analyser from 0° to 90° as if intensity of out coming ray varies from maximum to minimum then the ray is a) an ordinary ray b) a plane polarized ray c)a partially plane polarized ray d) none of these 51.A plano convex lens of radius 3 m is placed on the optically flat glass plate and is illuminated by monochromatic light. The radius of the 8th dark ring is 3.6mm. Then the wavelength of light is a) 5600 A b) 540 nm c) 4800 A d) 5890 A


52.The optical rotation does not depend on a) thickness of the crystal b) velocity of the incident light c)density of the crystal d) temperature of the solution 53.The path difference between two monochromatic light waves of wavelength 4000A0 is 1000 A0. The phase difference between them is a) b) 2 c) 3/2 d) /2 54. In young’s experiment the width of third bright band is 2 mm when a light ray of wavelength 6000 A0 is used. Find the width of sixth dark band a) 3mm b) 6mm c) 2mm d) 4mm 55.Wavelength of light in vacuum is 6000A0. Then its wavelength in a medium of refractive index 4/3 is a) 4000A0 b) 4500A0 c) 5x10-7 m d) 3x108m 56.In Young’s experiment two light rays of wavelengths 4200A0 and 5400A0 are used. Let D and d are taken as constants, the ratio of the band produced in both cases is given by a) 9:7 b) 8:3 c) 7:9 d) 3:8 57. In Newton’s ring experiment when a light ray of wavelength 5000 A0 is used. Calculate the thickness of the air film at which 18th dark ring is produced. a) 5.5 x 10-7 m b) 3.4 x 10-6 m c) 5x 10-6 m d) 4.5 x 10-4 cm 58. In young’s experiment the distance of the 5th dark band from the central bright band is given by

a) xn = b) x = c) x = ( ) d) x = 59. In young’s experiment blue colour light is used. If it is replaced by orange colour light then the band width will be a) decreased b) doubled c) halved d) increased 60. Property of light explained by corpuscular theory is a) Interference b) refraction c) diffraction d) polarization 61.The refractive index of glass is 1.5 What is its refractive index with respect to water? a) 1.995 b) 0.8866 c) 1.125 d) 1 62.If 10000 rulings are present in one meter length of a plane diffraction grating then the grating element is equal to


a) 1 x 105 m b) 1 x 10 -4 m c) 1 x 10 3 m d) 1 x 10 7 m 63.A Nicol prism has its length and breadth in the ratio a) 3 : 1 b) 2 : 1 c) 1 : 3 d) 2 : 3 64.When sodium light passes along the optic axis of a calcite crystal the refractive index for extraordinary ray is a) 1.486 b) 1.532 c) 1.615 d) 1.658 65.The wavelength of light used in Newton’s rings when radius of first order ring and radius of curvature of lens respectively are 1.21 mm and 3 m is a) 4880 A b) 5500 A c) 3900 A d) 7800 A 66.Harmful rays in solar spectrum are a) Gamma rays b) IR rays c) UV rays d) X-rays 67.Ration of radii of 4th and 25th rings of the Newton’s rings is a) 2.5 b) 0.8 c) 0.4 d)0.16 68.Two coherent sources have wavelength A and B. Then a) A = B b) A B c) A B d) none of these 69.The critical angle for a medium is 30° . The angle of incidence for total internal reflection is a) equal to 30° b) less than 30° c) equal to 90° d)greater than 30° 70.Which one of the following are not electromagnetic waves? a) Gamma rays b) X – rays c) Beta rays d) Micro waves 71.The refractive index of the medium is √3. If the unpolarised light is incident on it at the polarizing angle of the medium. then the angle of refraction is a) b) c) d) 72.Emission, absorption and interaction of light with matter are explained by a) Corpuscular theory b) Wave theory c) Electromagnetic theory d) quantum theory 73.When a Polaroid is rotated, the intensity of the light does not vary, then the incident light is a) un polarised b) completely polarised c) partially polarised d) quarterly polarised 74. If an electromagnetic wave is propagating along x – direction and electric field variation is along y – direction then the magnetic field variation will be a) along x – direction b) inclined at an angle of 45° with x - direction


c) along y direction d) along z direction 75.If the refractive index of second medium with respect to the first medium is greater than one. then it implies that a) first medium is rarer and the second medium is denser b) first medium is denser and the second medium is rarer c) velocity of light in the first medium is less than that in the second medium d) velocity of light is same in both media. 76.Of the following optically active material is a) sodium chloride b) calcium chloride c) sodium d) chlorine 77.In Raman effect. if the wavelength of the incident light and Anti – stoke’s lines are 5461 A0 and 5441 A0 the wavelength of the stokes lines will be a) 5451A0 b) 5481 A0 c) 5461 A0 d) 5420 A0

78. If the velocity of light in a medium is 2.25 x 108 ms-1 then the refractive index of the medium will be a) 1.5 b) 0.5 c) 1.33 d) 1.73 79. If the wavelength of light wave in vacuum is 6.4 x 10-7 m, the wavelength of light wave in water of refractive index 1.33 will be a) 4 x 10-7 m b) 4 .8 x 10-7 m c) 2.64 x 10-7 m d) 5 x 10-7 m 80.The refractive indices for glass and water respectively is 1.5 and 1.33, then the ratio of velocity of light in glass and water is a) 4 : 3 b) 3 : 4 c) 8 : 9 d) 9 : 8 81.The distance between the two corresponding points in a grating is 2x10-4 cm. The number of lines per meter width of the grating will be a) 20000 b) 2000 c) 500000 d) 50000 82.The polarizing angle for water is 570 30′.If the light incident at this angle on the surface of water and reflected, the angle of refraction in water is a) 570 30′ b) 32° 50′ c) 32° 30′ d) 32° 10′ 83.The velocities of red light (600 nm) and violet light (400 nm) in free space are in the ratio of a) 2 : 3 b) 1 : 2 c) 3 : 2 d) 1 : 1 84.In a scattering experiment, the wavelength of stokes and anti – stokes lines are found to be 589.3 nm and 588.7 nm respectively. The wavelength of


unmodified lines is a) 5890 A b) 598 nm c) 589.9 nm d) 5881 A 85.In Raman effect, if 휗 is the frequency of incident light and ∆휗 is the Raman shift, the frequency of anti – Stoke’s lines is

a) 휗 b) 휗+ ∆휗 b) 휗 −∆휗 d) 휗 + ∆ 86.In Raman scattering with the incident photon of frequency 5.357x1014 Hz, anti – Stoke’s line is found to be at 5.556 x 1014 Hz. The frequency of Stoke’s line is a) 5.755 x 1014 Hz b) 5.457 x 1014 Hz c) 5.158 x 1014 Hz d) 5.655 x 1014 Hz 87.The central fringe in young’s experiment is bright, because the path difference is a) λ b) λ/2 c)2λ d) zero 88. In young’s experiment by doubling the distance between the slits and screen and by halving the distance between the slits, the fringe width becomes a) doubled b) halved c) quartered d) quadrupled 89. In Raman spectrum, stokes and anti Stoke’s lines are found at 5.84 x 1014 Hz and 5.9 6 x 1014 Hz respectively. The frequency of Rayleigh line is a) 5.9 x 1014 Hz b) 6.0 x 1012 Hz c) 6.62 x 1014 Hz d) 5.78 x 1014 Hz 90.The value of ratio of amount of scattering by two waves of wavelengths 400 nm and 600 nm is a) 0.66 b) 15 c) 5.1 d) 1.5 91.In young’s experiment, by using two sources of wavelengths λ1 and λ2 the fringe widths are found to be 2 nm and 2.55 nm and if λ2 = 6.65 x 10-7 m, what is λ1 ? a) 8312.5A b) 5215 A c) 5948 A d) 6850A 92.In a young’s double slit experiment, light rays of two different wavelengths are used. If the ratio of the widths of the 3rd bands for the two rays is 7, what is the ratio of corresponding wavelengths? a) 1/71/3 b) 71/3 c) 1/7 d) 7 93.In diffraction of composite light by grating the zeroth order image is a) yellow b) red c) white d) multi colour 94.When a ray of light is incident on a glass surface at polarizing angle of


570 30′,the angle between the incident ray and the reflected ray is a) 570 30′ b) 350 30′ c) 115° d) 90° 95.Unpolarised light passes through a tourmaline crystal. The emergent light is analysed by analyser. When the analyser is rotated through 90°the intensity of light. a) remains uniformly bright b) remains uniformly dark c) varies between maximum and minimum d) varies between maximum and zero 96.Which one of the following is not an electromagnetic wave? a) X-rays b) γ-rays c) U-V rays d) β-rays 97. If C is the velocity of light in vacuum, the velocity of light in a medium with refractive index is

a) C b) c) d)

98. A ray of light passes from a denser medium into a rarer medium. For an angle on incidence of 45°, the refracted ray grazes the surface of separation of the two media. The refractive index of the denser medium is

a) b) √

c) √2 d) 2 99. In Newton’s rings experiment, light of wavelength 5890A0 is used. The order of the dark ring produced where the thickness of the air film is 0.589 m is a) 2 b) 3 c) 4 d) 5 100. In Raman effect, if the scattered photon gains energy, it gives rise to a) Stokes’ line b) anti-Stokes’ line c) Stokes’ and anti-Stokes’ lines d) Rayleigh line 101. A ray of light is incident on a glass surface such that the reflected ray is completely plane polarized. The angle between the reflected ray and the refracted ray is a) 57.5° b) 32.5° c) 90° d) 115° 102.The fringe width for red light as compared to that of violet light is almost a) thrice b) double c) four times d) eight times 103. In Newton’s ring experiment, for the light of wavelength λ, the first bright ring appears when the thickness of air film is a) λ/2 b) λ c) λ/4 d) 3λ/2 104. If the radius of the first Newton’s ring is 1.89 x 10-3 m, the radius of the


fourth Newton’s ring is a) 7.56 x 10-6 s b) 0.378 x 10-4 m c) 0.378 x 10-3 m d) 3.78 x 10-3 m 105. Refractive indices of glass and water are 3/2 and 4/3 respectively. The ratio of the speed of light in water to that in glass is a) 1 : 1 b) 8 : 9 c) 9 : 8 d) 4 : 15 106.The overlapping in certain parts of the electromagnetic spectrum reveals that the particular wave a) can be produced by only one method b)has very high energy values c) can be produced by different methods d) has very low energy values 107.The spectrum consisting of unbroken luminous bands of all wavelength containing all colours from red to violet is given by a) mercury in mercury vapour lamp b)calcium and barium salts in Bunsen flame c)carbon arc lamp d) CO2 gas in molecular state in discharge tube 108.Soap bubbles exhibit brilliant colours in sun light due to a) scattering of light b) diffraction of light c) Polarisation of light d) interference of light 109.If ‘i’ is the angle of incidence, the angle between the incident wave front and the normal to the reflecting surface is a) i b) 900- i c) 900 + i d) i- 900 110.In a Nicol prism, the ordinary ray is prevented from coming out of Canada balsam by the phenomenon of a) reflection b) polarization c) diffraction d) total internal reflection 111.In Young’s double slit experiment , bandwidth contains a) a bright band only b) a dark band only c)either a bright band or a dark band d) both a bright and a dark band 112.For a given angle of incidence , a refracted wave front is possible if a) sin r 1 b) sin r = 1 c) sin r1 d) sin r = 113.Electromagnetic waves are generated by a) varying magnetic field b) electric charges which are at rest c) accelerated electric charges d) accelerated magnetic poles 114.A carbon arc lamp, often used in cinema theaters, gives a a) line spectrum b) continuous spectrum c) band spectrum d) absorption spectrum


115.In an electromagnetic wave, variations in electric and magnetic fields occur. a) simultaneously in the same plane b) at different instants in the same plane c) at different instants in perpendicular planes d) simultaneously in perpendicular planes 116.Line spectra are often obtained from a) a discharge tube containing ammonia b) a discharge tube containing xenon gas at high pressure c) atoms in the gaseous state d) carbon di-oxide lamp 117.The spectrum which can be used as a means of identifying an element is a) line spectrum b) continuous spectrum c) band spectrum d) band absorption spectrum 118.A pure green glass when placed in the path of white light gives a) continuous absorption spectrum b) line spectrum c) absorption spectrum d) line absorption spectrum 119.Solar spectrum is an example for a) continuous absorption spectrum b) line spectrum c) absorption spectrum d) line absorption spectrum 120.If the velocity of light in vacuum is C ms-1, then the velocity of light in a medium of refractive index 1.6 is a) 1.6 cms-1 b) C/1.6 ms-1 c) 1.6/C ms-1 d) C ms-1 121.In which of the following media the velocity of light is maximum? a) water b) air c) glass d) salt water 122.When a ray of light enters a glass from air a) its wavelength decreases b) its frequency decreases c) its wavelength increase d) neither its wavelength nor its frequency changes 123.When interference of wave takes place, there is redistribution of a) amplitude b) frequency c) intensity of light d) phase 124.If the path difference between two waves is x , then the phase difference is a) 2 x b) 2x/ c) /2x d) 2x


125.If the path difference corresponding to a phase difference of is a) 2 b) /2 c) (3/2) d) /4 126.The fringe width in Young’s double slit experiment can be increased by decreasing a) the distance between the slit and the screen b) the distance between the slits c) the width of the slit d) the wavelength of light 127.In double slit interference experiment, when yellow light is replaced by a red light, the fringe width. a)decreases b) increases c) remains the same d)becomes zero 128.The colour of oil spread on a patch of water on the road in a rainy

day is due to a) polarization of light b) diffraction of light c) interference of light d) reflection of light 129.When viewed a white light, soap bubbles show colour due to a) interference b) scattering c)diffraction d) total internal reflection 130.If a white light is used the centre of Newton’s rings is a) bright b) violet c) red d) dark 131.The bending of light around the edges of an obstacle is called a) dispersion b) refraction c) deviation d)diffraction 132.Diffraction of light is in accordance with a) the corpuscular theory of light d)the quantum theory of light c) the electromagnetic theory of light b) the wave theory of light 133.Diffraction effects are more in the case of sound waves than in the case of light waves because a) the wavelength of sound waves is less than that of light wave b) the velocity of sound is less than the velocity of light c) sound waves are longitudinal and light waves are transverse d)the wavelength of sound waves is greater than that of light wave 134.In Fresnel diffraction, the wave front undergoing diffraction is a) spherical or cylindrical b) plane c) elliptical d) elliptical 135.Constructive interference takes place when the phase difference between them is


a)2 b) c) /2 d)3/2 136.In a diffraction grating, the grating element is a) the total number of ruling drawn b) the number of slits or opaque portions c) the combined width of a ruling and a slit d) the total width of the grating itself 137.The corresponding points on a grating are the points a) on the extreme positions b) which are separated by a distance equal to a grating element c) lying on either side of a slit

d) lying on either side of a ruling 138.Grating can be used to determine a) velocity of light b) wavelength of light

c) frequency of light d) amplitude of light 139.From Brewster’s law, we find that polarizing angle depends on a) the plane of vibration of the beam b) the plane of polarization of the beam c) the refractive index of the medium d) the thickness of the medium 140.Double refraction is exhibited by a) glass b)gas c) calcite d) liquid 141.The velocities of the extraordinary ray and ordinary ray in calcite crystal are a) same in all direction b)different in all direction c) same in only one direction namely along the optic axis d) zero in one direction and more than zero in perpendicular

direction 142.In a doubly refracting crystal, along the optic axis, the ordinary ray and the extraordinary ray a) travel with the same velocity b) have different velocities c) travel slowly d) travel fast 143.Polaroids are used in aero planes a) to reduce pressure b)to increase incoming radiation c) to reduce incoming radiation d) to increase pressure 144.In Hertz’s experimental set up the metal plates act as a a) capacitor b) inductor c) resistor d) conductor 145.In fluorescence atoms in excited state returns back to lower state


in a time a) equal to 10-5s b)less than 10-5s c)greater than 10-5s d) 10-5s 146.The temperature of photo sphere of sun is a) 14 million K b) 6000K c) 14000K d) 600K 147.The ratio of amount of scattering of two wavelength is 81:256 ,the ratio of their wavelength is a) 3:4 b) 4:3 c) 2:3 d) 3:2 148.The wavelets from a wave front reaches a point in 0.334s. The point is at a distance of a) 100m b) 1m c)100cm d) 1cm 149.Coherent sources are obtained by a) two independent sources b) two sources c) a single source of light c) diffraction 150.The radii of nth dark rings in Newton’s ring experiment done in air and the given liquid are respectively1.732 mm and 1.414 mm. The refractive index of the liquid is a) 1.33 b)1.5 c) 1.6 d) 1.7 151.In a grating there are 5000 lines per cm. The grating element is a) 0.2m b) 2m c) 5m d) 0.5m 152.In diffraction pattern the fringes are a) equally spaced b) of same intensity c) unequally spaced d) having full dark 153.Number of fringes obtained in diffraction is a) less than that in interference b) greater than that in interference c) equal to that in interference d) zero 154.Polarisation of light implies that light waves are a) longitudinal b) transverse c) mechanical d) electromagnetic wave 155.Which is not a polarizer? a) tourmaline crystal b) pile of plate c) Nicol prism d) diffraction grating 156.The instrument used to determine the optical rotation is a) interferometer b) spectrometer c) polarimeter d) mass spectrometer 157.Pile of plates employs the principle of a) double refraction b) polarization by reflection c) Polaroid d) total internal reflection 158.The wavelength of the electromagnetic waves produced by Hertz is a) 5m b) 6m c) 6A0 d) 7m 159.The phenomenon of interference establishes that light


a) travel in straight line b) requires a medium to travel c) travels in the form of waves d) is made up of particles 160.The transverse nature of light waves is demonstrated only by the phenomenon of a) interference b) diffraction c) polarization d) reflection 161.An electromagnetic wave has 5J of electric energy. The magnetic energy is a) zero b) 5J c) 10J d) 2.5J 162.The velocity of light in vacuum can be changed by changing a) frequency b) wavelength c) amplitude d) none of the above 163.Which one of the following groups of electromagnetic waves is in order of increasing frequency? a) microwaves, ultraviolet rays, X-rays b) radio waves, visible light, Infra red radiation c) gamma rays, visible light, ultraviolet rays d) gamma rays, ultra rays, radio waves 164.Pick out the longest wavelength from the following types of radiations a) blue light b) gamma rays c) x-rays d) red light 165.Which of the following electromagnetic radiations has the smallest wave lengths? a) microwaves b) ultra violet rays c) X-rays d) gamma rays 166.White light is passed through green glass, glass appears as a) white b) black c) green d) red 167.The wavelength of light diminishes times in a medium. A diver from inside water looks at an object whose natural colour is green. He sees the object as a) green b) blue c) yellow d) red 168.If a glass rod is immersed in liquid of the same refractive index then it will a) look bent b) disappear c) look longer d) none of these 169.The speed of light in glass is a) the same as in air b) greater than the speed in air c)less than the speed in air d) less than the speed of sound in air 170.A ray of light takes 2s to pass through a medium of thickness 400 m. The refractive index of the medium is a) 1.333 b) 1.600 c) 1.732 d) 1.500 171.It is possible to observe total internal reflection when a ray travels from a) air into water b) air into glass c) water into glass d) glass into water 172.Which of the following is conserved when light waves interfere?


a) intensity b) energy c) mass d) amplitude 173.The phenomenon of diffraction cannot be explained by corpuscular theory because a) the corpuscles cancelled the effect of one another b) the corpuscles have appreciable mass c) some of the corpuscles are not in a mood to be deviated d) the corpuscles traveling at high speed will not be deviated from its straight line path 174.When a polarizer is rotated , the intensity of light varies but never reduces to zero because light is a) partially plane polarized b) un polarized c) completely polarized d) none of the above 175.The light emerging from a Nicol prism a) has vibrations in all direction b) has vibrations in one direction only c) has vibrations in two mutually perpendicular directions d) has no vibration mutually 176.Corpuscles are nothing but a) ether particles b) electrons c) protons d) perfectly elastic , tiny ,weightless particles 177.Light behaves as a) particles in high energy region and waves in low energy region b) waves in high energy region and particles in low energy region c) particles in high and low energy region d) waves in high and low energy region 178.In Young’s double slit experiment , if one of the slits is covered , then a) fringes will disappear b) bright bands will be seen c) dark bands will be seen d) fringe width will increase 179.Corresponding points on a grating are any two points in adjacent slits a) equal to 1/2 of the grating element b) equal to 1/4 of the grating element c) equal to 3/4 of the grating element d) equal to grating element 180.Unpolarised light means light with a) many wavelengths b) many different amplitude waves c) vibrations taking place in all possible directions d) varying intensity at a given point 181.In an electromagnetic wave a) power is equally transferred along the electric field and magnetic field


b) power is transmitted in a direction perpendicular to both the fields c) power is transmitted along electric field d) power is transmitted along magnetic field 182.In total internal reflection the angle of incidence inside the denser medium a) is greater than the critical angle b) is lesser than the critical angle c) is equal to the critical angle d) is equal to 900 183.The relation connecting the critical angle ‘C’ and the refractive index of the denser medium is a) = Sini /SinC b) = SinC c) = 1/SinC d) =SinC/Sinr 184.Light waves pass through vacuum because they are a) longitudinal in nature b) transverse in nature c) electromagnetic in nature d)mechanical waves in nature 185.According to Huygen’s wave theory the angle of incidence is equal to the angle between a) the incident wave front and the reflecting surface b) the normal and the incident wave front c) the normal and the incident ray d) the normal and reflected ray. 186.According to Huygen’s wave theory the angle of reflection is equal to the angle between a) the reflected wave front and the reflecting surface b) the normal and the reflected wave front c) the normal and the reflected ray d) the normal and incident ray. 187.According to Huygen’s wave theory the angle of incidence is equal to the angle between a) the refracted wave front and the normal b) the refracted wave front and the surface of separation c) the refracted and the normal d) the reflected ray and the normal 188.The wave front emitted by a slit source is a) plane b)cylindrical c) spherical d) circular 189.The colours present in the …… spectrum depend upon the temperature of the source a) line spectrum b) band spectrum c) continuous spectrum d) absorption spectrum 190.Corpuscular theory of light could not explain a) polarization of light b) rectilinear propagation of light c) refraction of light d) reflection of light 191.Assuming light waves to be longitudinal, ……. property of light could not explained by Huygen’s


a) transverse b)dual c) rectilinear propagation d) particle 192.When a monochromatic beam of light passes from a denser medium into rare medium, its a) velocity decreases b)frequency increases c) frequency decrease d) wavelength increase 193.The deviation of a ray of light in passing from one medium into another medium is known as ….. a) polarization d) diffraction c) refraction d) interference 194.The frequency of light having wavelength 6000 A0 is a) 0.50 x 1018 Hz b) 0.50 x 1015 Hz c) 0.05 x 1018 Hz d) 5 x 1018 Hz 195.Continuous spectrum depends only on the …… of the source. a) characteristics b) temperature c) density d) volume 196.The frequency of incident and scattering radiations are respectively 5x1014 Hz and 5.2x1014 Hz. The Raman shift and type of lines are a) 2x1013 Hz Stoke’s line b) 2x1013 Hz Anti-Stoke’s line c) 2x1013 Hz unmodified line d) 2x1012 Hz Stoke’s line 197.If the critical angle for total internal reflection from medium to vacuum is 300, the velocity of light in the medium is a) 3x108 ms-1 b) 1.5x108 ms-1 c) 6x108 ms-1 d) 1.732x108 ms-1 198.Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index 3/2 is a) 2x10-4 s b) 2x108 s c) 2x10-11 s d) 2x1011 s 199.In Newton’s rings experiment the path difference of interfering waves is a) the thickness of air film b) twice the thickness of air film c) half the thickness of air film d) the thickness of glass plate 200.The centre of Newton’s rings appears dark because a) the thickness of air film is not zero b) the thickness of air film is zero c) the thickness of air film introduce an additional path differences /2 d) the thickness of air film introduce an additional path differences /4 II. IMPORTANT UNITS


1.The unit of refractive index of a medium is ………. 2.The unit of wavelength is …………. 3.The unit of bandwidth is …….. 4.The unit of grating element is …… 5.The unit of frequency is …… 6.The unit of specific rotation …….. 7.The unit of velocity of light is …… 8.The unit of path difference is …… 9.The unit of phase difference is …….. 10.The unit of radius of curvature of a lens is ……. 11.The unit of grating constant(No. of grating element per unit length) is ……… III. STANDARD VALUES 12.In electromagnetic waves, angle between electric and magnetic field vectors is 13.The electromagnetic waves travel in vacuum or free space with a velocity of 14.The distance between two metal plates of Hertz arrangement is …….. 15.Hertz with his experiment set-up produced electromagnetic waves of frequency 16.The frequency of AM band ranges from …… to …… 17.The frequency of television waves ranges from …… to ……. 18.The wavelength two sodium lines formed in the sodium spectrum are ….. and 19 The frequency of FM ranges from …….. to …….. 20.The wave length range of visible light is ……… and ……. 21.The temperature of the photosphere , the centre core of the sun is in the order of …… 22.The temperature of the chromo sphere, the outer layer of the sun is …… 23.The polarizing angle for glass is ……….. 24.The phase angles of the Nicol prism is ……… 25.The refractive index for Canada balsam is ……. IV. IMPORTANT FORMULAE 1.Velocity of electromagnetic wave in vacuum is ………. 2.According to Snell’s law , the refractive index of medium is ………. 3.Refractive index of medium in terms of wavelength is ……….. 4.Refractive index of medium in terms of velocity is ……….. 5.The ratio of maximum intensity to minimum intensity is …… 6.In Young’s double slit experiment , the condition for constructive interference is ………


7. In Young’s double slit experiment , the condition for destructive interference is ……… 8.Band width is …….. 9.The condition for the constructive interference in thin films due to reflected light is ……… 10.The condition for the destructive interference in thin films due to reflected light is ……… 11.The condition for the constructive interference in thin films due to transmitted light is ……… 12.The condition for the destructive interference in thin films due to refracted light is ……… 13.In Newton’s rings experiment the condition for bright image is ….. 14. In Newton’s rings experiment the condition for dark image is ….. 15.The radius of the nth dark ring is ……… 16. In Newton’s rings experiment the wavelength of light used is ….. 17.Using Newton’s the refractive index of a liquid is ………. 18.According to Brewster’s law , the refractive index is ………. 19. According to Brewster’s law , the angle of refraction is ………. 20.The grating element is ………. 21.In case of plane transmission grating the wavelength used is …… 22.Specific rotation is ………. V.THREE MARK QUESTIONS I.DEFINATIONS: 1. Define wave front. 2. Define interference. 3. Define diffraction. 4. Define polarization. 5. Define plane polarized light. 6. Define optic axis of a crystal. 7. Define specific rotation. 8. Define bandwidth. 9. Define polarizing angle. 10. Define grating element.


11. Define corresponding point of a grating. 12. Define total internal reflection. 13. Define critical angle. 14. Define coherent sources. II. LAWS AND PRINCIPLES 15. State Rayleigh’s scattering of light. 16. What is Tyndal Scattering law. 17. What is Raman effect? 18. State Huygen’s principle. 19. What is the principle of superposition of waves? 20. State Brewster’s law. 21. State double refraction. 22. State total internal reflection. 23. State the principle of pile of plates. 24. State the laws of reflection. 25. State the laws of refraction. III.USES.(APPLICATIONS) 26. State the uses of Fraunhofer lines. 27. State the uses of Infra red rays. 28. State the use of pile of plates. 29. State the uses of Microwaves. 30. State the uses of Ultra –Violet radiations. 31. State the uses of x-rays. 32. State the uses of -rays. 33. Give the applications of Raman Spectrum. 34. Mention any three uses of Polaroids. IV.PROPERTIES(CHARACTERISTICS) 35. Give any three characteristics of electromagnetic waves. V.REASONING QUESTIONS 36. Why the sky appears blue in colour? 37. Sun appears reddish at sunrise and sunset . Why? 38. Two identical monochromatic sources cannot be coherent . Why? 39. Why is the centre of the Newton’s ring dark? VI.DISTINGUISHING AND DIFFERENTIATING QUESTIONS 40. Distinguish between line spectrum and continuous spectrum. 41. Distinguish between corpuscles and photons.


42. Distinguish between Fresnel and Fraunhofer diffraction. 43. Mention the difference between interference and diffraction. 44. Differentiate between polarized and un polarized light. 45. Distinguish between plane of vibration and plane of polarization. 46. Differentiate between ordinary ray and extra ordinary ray. VII.THEORY QUESTIONS 47. What are the Fraunhofer lines? 48. What is fluorescence? 49. What is phosphorescence? 50. What are the conditions for total internal reflection? 51. Give conditions for sustained interference. 52. State the conditions for obtaining clear and broad interference bands. 53. What are Newton’s rings? 54. How will you test a polarized light and partially polarized light? 55. What are uniaxial and biaxial crystals? Give examples. 56. On What factors does the amount of optical rotation depend? 57. State the reason for colouring of thin film. On what factors does the colour of the thin film depend upon? 58. What is meant by plane transmission grating? VIII DIAGRAMS,CIRCUITS. 59. Draw the diagram of Hertz arrangement for producing electromagnetic waves. VI. THREE MARK PROBLEMS

1.Calculate the energy of a photon of red light of wavelength 6000Ao. 2.If the ratio of the wavelengths of two light waves is 5 : 2 . Then find the ratio of the amounts of their scattered light . 3.In Raman effect if the wavelength of the incident light and Anti-stoke’s lines are 5461 Ao and 5441A0 respectively. Calculate the wavelength of the Stoke’s line. 4.A light ray of frequency 6.26 x 1014 Hz is scattered by a pure liquid. The wavelength of the Anti- Stoke’s line is 4792 Ao .What is the wavelength of the Stoke’s line? 5.Sodium D1 line (5896Ao) is incident on a liquid. The frequency of scattered photon is 50 x1013 Hz. Calculate the Raman shift. 6.Refractive index of glass is 3/2. Calculate the time taken for light to pass through a glass plate of thickness 7 cm.


7. If the velocity of light in vacuum is c then the velocity of light in a medium of refractive index 1.6 is 8.If c is the velocity of light in vacuum, what is the velocity of light in glass with refractive index 3/2? 9.Velocity of light in air is 3 x 108 ms-1. What will be the velocity of light in a medium of refractive index 1.4? 10.Refractive indices of glass and water are 3 /2 and 4/3 respectively. Calculate the ratio of the speed of light in water to that in glass. 11.If the critical angle for total internal reflection from medium to vacuum is 30o. Calculate the velocity of light in the medium. 12.In Young’s double slit experiment the distance of the screen from the plane of the coherent sources is D = 2 m and the fringe width is 4 mm. Calculate the fringe width when the distance D is increased to 2.5 m. 13.Young’s double slit experiment, the fringe width is found to be 0.4 mm. Calculate the new fringe width if the whole apparatus is immersed in water of refractive index 4/3 without disturbing the geometrical arrangement. 14.In Young’s double sit experiment, light waves of wave lengths 1 and 2

are used keeping the distance between the distance from the slits undisturbed. If the corresponding bandwidths are 2mm and 2.5mm if 2 is 6650 Ao. what is the value of 1? 15.The diameter of the 10th dark ring in Newton’s ring experiment viewed normally by reflected light is 0.6 cm. Calculate the radius of curvature of the convex surface of the lens if the wavelength of light used is 6 x 10-5 cm. 16.What is the approximate radius of the plano-convex lens used in a Newton’s ring experiment if the wavelength of light used is 5645 Ao and the radii of the 10th and 20th rings are 3.36 mm and 5.82 mm respectively? 17.In a Newton’s rings experiment the radii of the kth and (k+8)th rings are respectively 5 mm and 5 mm. What is the value of k? 18.In a Newton’s rings experiment, the diameter of the 10th dark ring is 1.2 cm. If the wavelength of light used is 6000 Ao. Calculate the radius of curvature of the lens surface in contact with the glass plate. 20.In Newton’s rings experiment, the radius of a plano convex lens is 3 m. If the radius of the sixth dark ring is 3 mm calculate the wavelength of light 21.A parallel beam of monochromatic light is allowed to be incident normally on a plane diffraction grating having 5000 lines / cm and a second order maximum intensity is observed at a diffraction angle of 30o. Calculate the


wavelength of the light source used. 22.A ray of monochromatic light of wavelength 6000Ao fallsnormally on a plane transmission grating having 4000 lines per centimeter. The angle of diffraction for a particular order maximum is found to be sin-1 (0.4800). Then calculate the order of the maximum. 23.Monochromatic light of wavelength 5000 Ao is incident normally on diffraction grating having 5000 lines per cm. Calculate the angle of diffraction for the second order maximum. 24.If the grating element is equal to four times the wavelength of the light used, then calculate the possible maximum order of the diffracted image obtained. 25.In Young’s experiment , the width of the fringes obtained with light of wavelength 6000A0 is 2 mm . Calculate the fringe width if the entire apparatus is immersed in a liquid of refractive index 1.33. 26.A light of wavelength 6000 A0 falls normally on a thin air film ,6 dark fringes are seen between two points. Calculate thickness of the air film. 27. The polarizing angle for water is 53.40 . Calculate its refractive index. 28.The width of the rulings in a grating is 4x10-7 m . Calculate the grating element. 29.Find the radius of curvature of the lens used in Newton’s rings ,with the light of wavelength 5890A0, the diameter of the first dark ring is 6 mm 30.In Young’s experiment , the width of the fringes obtained with light of wavelength 6000A0 is 2 mm . Calculate the fringe width if the entire apparatus is immersed in a liquid of refractive index 1.33. 31.A light of wavelength 6000 A0 falls normally on a thin air film ,6 dark fringes are seen between two points. Calculate thickness of the air film. 32.The polarizing angle for water is 53.40 . Calculate its refractive index. 33.The width of the rulings in a grating is 4x10-7 m . Calculate the grating element. 34.Find the radius of curvature of the lens used in Newton’s rings ,with the light of wavelength 5890A0, the diameter of the first dark ring is 6 mm V.SHORT ANSWER (5 MARK QUESTIONS) 1.Mention the characteristics of electromagnetic waves. 2.Explain Hertz experiment for the confirmation of the existence of electromagnetic waves.


3.Explain the construction of wave front on the basis of Huygin’s principle. 4.Explain the phenomenon of total internal reflection by wave theory. 5.State and explain Brewster’s law. 6.Explain piles of plates with diagram. 7.Explain the phenomenon of double refraction. Bring out the differences between ordinary and extraordinary ray. 8.Explain the construction of Nicol prism. 9.Mention the uses of Polaroids. 10.Describe an experiment to demonstrate the transverse nature of light. 11.Describe an experiment to determine wavelength using a plane transmission grating. 12.Explain Newton’s corpuscular theory of light. 13.Explain the method of producing polarized light by reflection. 14.Describe the experimental arrangement and theory to produce Newton’s rings. VI.ESSAY TYPE QUESTIONS ( 10 MARK) 1.Explain emission and absorption spectra. 2.Explain the Raman scattering of light with the help of energetic level diagram. 3.Derive an expression for bandwidth of interference fringes in Young’s double slit experiment. 4.Discuss the theory of interference in thin transparent film due to reflected light and obtain condition for the intensity to be maximum and minimum. 5.Discuss the theory of plane transmission grating. 6.Using Huygen’s principle ,verify the laws of reflection. 7.Using Huygen’s principle ,verify the laws of refraction. 8.Derive an expression for the radius of nth dark ringin Newton’s rings experiment. Using it, determine the (i) wavelength of light and (ii) refractive index of the liquid.


KEY-5 LESSON

1 d 21 d 41 d 61 c 81 c 101 c 121 b 141 c 161 b 181 b 2 c 22 b 42 a 62 b 82 c 102 b 122 a 142 a 162 d 182 a 3 a 23 b 43 b 63 a 83 d 103 c 123 c 143 c 163 a 183 c 4 c 24 b 44 d 64 a 84 a 104 d 124 b 144 a 164 d 184 c 5 d 25 a 45 b 65 a 85 b 105 c 125 b 145 b 165 d 185 a 6 c 26 c 46 c 66 c 86 c 106 c 126 b 146 a 166 c 186 a 7 a 27 c 47 d 67 c 87 d 107 c 127 b 147 b 167 b 187 b 8 a 28 b 48 d 68 a 88 d 108 d 128 c 148 a 168 b 188 b 9 a 29 b 49 c 69 d 89 a 109 b 129 a 149 c 169 c 189 c 10 a 30 c 50 c 70 c 90 c 110 d 130 d 150 b 170 d 190 a 11 b 31 a 51 b 71 d 91 b 111 d 131 d 151 b 171 d 191 c 12 d 32 d 52 b 72 d 92 d 112 b 132 d 152 c 172 b 192 d 13 c 33 a 53 d 73 a 93 c 113 c 133 d 153 a 173 d 193 c 14 d 34 c 54 c 74 d 94 c 114 b 134 a 154 b 174 a 194 b 15 c 35 c 55 b 75 a 95 d 115 d 135 a 155 d 175 b 195 b 16 a 36 b 56 c 76 a 96 d 116 c 136 c 156 c 176 d 196 b 17 c 37 b 57 d 77 b 97 b 117 a 137 b 157 b 177 a 197 b 18 c 38 c 58 b 78 c 98 c 118 a 138 b 158 b 178 a 198 c 19 b 39 d 59 d 79 b 99 a 119 d 139 c 159 c 179176d 199 b 20 d 40 d 60 b 80 c 100 b 120 b 140 c 160 c 180 c 200 c

12th physics (vol 1)

Education