Physics Question paper

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UNIVERSITY OF KERALA B.Sc Degree Programme in (Core) Physics

Model Question Paper PY1141 –Basic Mechanics and Properties of Matter

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE]

I 1. Within the elastic limit, the ratio of the lateral strain to linear strain is called

(a) Young’s modulus (b) Bulk modulus (c) Rigidity modulus

(d) Poisson’s ratio

2. The stress acting on a body has the dimensions same as that of

(a) Force (b) Pressure (c) Strain (d) Area

3. The elevation at the center of a uniformly bent beam is directly proportional to

(a) Young’s modulus (b) breadth of the beam (c) thickness of the beam

(d) load at the ends of the beam

4. With increase in temperature, the surface tension of a liquid

(a) increases (b) decreases (c)no change

(d) first increases and then decreases

II 5. The S.I unit of coefficient of viscosity is

(a) Ns/m2 (b) Ns2/m (c) Ns/m (d) Ns2/m2

6. Bernoulli’s theorem is not applied in

(a) Venturimeter (b) Viscometer (c) Aerofoil (d) Spray atomizer

7. The kinetic energy, of a particle executing SHM, at its mean position is

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(a) Maximum (b) Minimum (c) Zero (d) None of these

8. Moment of inertia of a rigid body is independent of

(a) Mass of the body (b) Axis of rotation (c) Radius of gyration

(d) Angular velocity

III 9. The moment of inertia of a solid sphere of mass M and radius R about a

diameter is _________

10. The Magnus effect is based on the principle of ________

11. The viscosity of a fluid is due to its _________

12. Within the elastic limit, the ratio of the stress to the strain is called ________

IV State whether the following statements are true or false.

13. The viscosity of a liquid increases with increase of temperature.

14. For a particle executing SHM, the total energy is conserved.

15. The surface tension is always tangential to the liquid surface.

16. Pitot tube is a device based on Bernoulli’s Theorem.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.]

17. Derive an expression for the moment of inertia of a disc about a tangent

in its plane.

18. Mass of a fly wheel is concentrated at its rim. Why?

19. At what position of a harmonic oscillator is its (i) velocity and

(ii) acceleration, a maximum. Give their values.

20. A needle can float in clean water but sinks in soap solution. Why?

21. Define Poisson’s ratio. Obtain its limiting values.

22. Name the factors on which the depression at the free end of a cantilever

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depend.

23. Water spread on a clean glass plate but collects into drops on a greased

plate. Why?

24. Distinguish between streamline and turbulent flow.

25. State and explain Work-Energy principle.

26. Write a note on I section girders.

27. Explain the variation of viscosity with temperature.

28. What is the P.E curve of a particle?

SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.]

29. A coin rolls on a horizontal plane without slipping. What

fraction of its total K.E is rotational?

30. A fly wheel of mass 25 kg has a radius of 0.2 m. It is making

240 rpm. What is the torque necessary to bring it to rest in 20

seconds.

31. Two wires made of the same material are subjected to a force

in the ratio 1:2. Their lengths are in the ratio 8:1. Find the

ratio of their extensions.

32. Find the period of oscillation and maximum acceleration of a

S.H.M given by the equation x = 2Sin(pt + p/2).

33. The excess of pressure inside a soap bubble of radius 6 mm is

balanced by 2 mm column of oil of density 800 kg/m3. Find

the surface tension of soap solution.

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34. Water is conveyed through a pipe of 0.08 m in diameter and 4

km in length at the rate of 120 litres/minute. Calculate the

pressure required to maintain the flow. Coefficient of

viscosity of water is 0.001Ns/m2. Atmospheric pressure is

1.01×105 N/m2.

35. A circular disc of mass 0.5 kg and diameter 12 cm is fixed

horizontally to the end of a wire of length 40 cm and radius

0.5 mm. Find the rigidity modulus of the material of the wire

if the period of oscillation is 1 second.

36. A uniform thin bar of mass 2 kg and length1.2 m is bent to

make an equilateral triangle. Calculate the moment of inertia

about an axis passing through the center of mass and

perpendicular to the plane of the triangle.

SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR]

37. State and prove parallel and perpendicular axes theorems.

Derive an expression for the M.I of a solid sphere about a

tangent.

38. With necessary theory explain how a compound bar

pendulum is used to find ‘g’ at a place.

39. Derive the Poiseuille’s formula for the rate of flow of a

liquid through a capillary tube. What are the limitations of

Poiseuille’s formula.

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Model Question Paper PY1221 –Methodology in Physics and Informatics

Time: 3 hours. Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE]

I. Choose the correct option 1. In science a theory is accepted or rejected based on a) authorities b) agreement with textbooks c) democratic principles d) experiments 2. Space research in India is led by

a) BARC b) DST c) CSIR d) ISRO

3. Repeated measurements help in canceling out a) random errors b) systematic errors c) spurious measurements d) relative errors

4. A student finds the mass and volume of a solid body with an expected error of 1% and uses the data to calculate density. Expected error in density would be,

a) nil b) 0.5% c) 1% d) 2%

II. Choose the correct option 5. An option that allows users to format pages, merge texts and pictures is a. mail merge b. word wrap c. outline d. page layout.

6. In html content of the page can be provided under which of the tag. a. Head b. Body c. Title. d. none of previous 7. Spell checking can be initiated by pressing the ------ function key a. F5 b. F6 c. F7 d. F8

8. Which measure of dispersion is easiest to calculate?

a) median b) mean c) standard deviation d) range

III. Match the following 9. Testing of hypothesis a) Observation and experiment

10. Literature survey b) sample survey

11. Method of data collection c) expert opinion

12. Empirical research d) chi-square test

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e) Academic journals

IV. State whether the following statements are true or false.

13. Aim of science is to find the ultimate truth. 14. Replication is an important criterion in experimental design. 15. In research methodology subjectivity is more important that objectivity. 16. Scientific method relies on empirical evidence.


17. Enlist some characteristic features of scientific method? 18. How does the case study method differ from the survey method? 19. What do you mean by repeatability of an experiment? 20. A clock is used to measure the period of a pendulum. Enlist possible sources of error. 21. Define standard deviation. 22. What is meant by dominant error? 23. What do you mean by primary data and secondary data? Give examples.

24. What is the use of Boarders and Shading options (in word) ? 25. Explain window –split and window –freeze panes in Excel 26. What is meant by a search engine? Name three search engines. 27. Explain Goal seek and solver commands in Tool menu. 28. How can you add sounds in power point slide?


29. Write short note on criteria of good research. 30. Write a short note on motivation in research. 31. What do you mean by literature survey in the context of research? 32. Write a brief note on space research program in India. 33. Explain the necessity for standardized units for measurement. 34. Point out the important limitations of tests of hypotheses. 35. Explain how errors are represented graphically. 36. Explain the concepts of absolute and relative errors.


37. Briefly describe the different steps involved in a research process. 38. The procedure of testing hypothesis requires a researcher to adopt several

steps. Describe in brief all such steps. 39. Discuss how experimental errors are estimated and reported.

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UNIVERSITY OF KERALA

B.Sc Degree Programme in (Core) Physics Model Question Paper

PY1341 –Thermodynamics and Statistical Physics Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE]

I. 1. When a gas is expanded adiabatically, the temperature

(a) Increases (b) Decreases (c) No change (d) None of these

2. The working of a refrigerator is based on

(a) Zeroth law of thermodynamics (b) First law of thermodynamics

(c) Second law of thermodynamics (d) None of these

3. The T-S diagram of an adiabatic process is

(a) A straight line parallel to the X axis (b) A straight line parallel to the Y axis

(c) A straight line inclined to the X axis (d) A curve

4. Which of the following remains unchanged during an adiabatic process

(a) Temperature (b) Pressure (c) Entropy (d) Volume

II 5. The efficiency of a Carnot engine working between 300K and 150K is

(a) 100% (b) 50% (c) 75% (d) 60%

6. A process in which the volume remains unchanged is called

(a) Isothermal process (b) Isobaric process (c) Isochoric process

(d) Adiabatic process

7. The Joule-Kelvin coefficient for a perfect gas is

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(a) Zero (b) One (c) Less than zero (d) Greater than one

8. In an irreversible process the entropy of the system

(a) Increases (b) Decreases (c) Unchanged (d) None of these

III. 9. The S.I unit of coefficient of thermal conductivity is ___________.

10. The indicator diagram of a process is a straight line parallel to the X axis.

It is an ___________ process.

11. For an ideal heat engine, the temperature of the sink is ___________.

12. The sum of the internal energy of a system and the product of its pressure and

volume is called __________.


13. Throttling process is an isenthalpic process.

14. The entropy of a system increases in all irreversible processes.

15. The efficiency of a petrol engine is greater than that of a diesel engine.

16. Thermal conductivity of copper can be determined by Lee’s disc method.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.

17. The first law of thermodynamics inculcates three related ideas. What are

they?

18. State the essential difference between the first and second laws of

thermodynamics.

19. Can you use Maxwell’s relations to derive first order phase transition

equation.

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20. State third law of thermodynamics.

21. Define solar constant.

22. What is phase space?

23. State Lioville’s theorem.

24. What do you know about fermions?

25. State Wiedmann-Franz law.

26. Distinguish between adiabatic and isothermal processes.

27. Explain the principle of increase of entropy.

28. Distinguish between thermal conductivity and thermometric conductivity.


29. Air is compressed adiabatically to half its volume. Calculate the change in its

temperature. ? = 1.4

30. A Carnot’s engine is operated between two reservoirs at temperatures 450K

and 350K. If the engine receives 100 J of heat from the source in each cycle,

calculate the heat rejected to the sink in each cycle, the efficiency of the

engine and the work done per cycle.

31. Find the increase in the boiling point of water at 1000C when the pressure is

increased by one atmosphere. Latent heat of vaporization of steam is

2.268×106 J/kg and 1 gram of steam occupies 1.677×103 cm3.

32. 10 grams of steam at 1000C is blown into 90 grams of water at 00C contained

in a calorimeter of water equivalent 10 gram. The whole steam is condensed.

Calculate the increase in the entropy of the system.

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33. The Fermi energy in copper is 7.04 eV. Approximately what percentage of the

free electrons in copper is in excited state at room temperature?

34. The Sun’s mass is 2.0×1030Kg, its radius is 7.0×108m and its surface

temperature is 5.8×103K. How many years are needed for the Sun to lose 1%

of its mass by radiation?

35. The opposite faces of a brass plate of 2 mm thick are at a temperature

difference of 1000C. The area of the plate is 0.02 m2. Find the quantity of heat

that flows through the plate in 1 minute if the thermal conductivity of brass is

110 W/m/K.

36. 10 kg of water at 1000C is converted into steam at the same temperature.

Calculate the change in entropy. The specific latent heat of steam is 2.268×106

J/kg.


37. Describe the working of a Diesel engine and derive the equation for its

efficiency.

38. Define thermal conductivity. Describe, with theory, an experiment to

determine the thermal conductivity of a bad conductor using Lee’s disc

method.

39. Distinguish between Maxwell-Boltzmann, Fermi-Dirac and Bose- Einstein

Statistics with examples

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Model Question Paper PY1441 –Electrodynamics


I. 1. The force between two electric charges is proportional to

(a) 1/r (b) 1/r2 (c) r (d) r2

2. The electric potential inside a uniformly charged sphere is

(a) uniform (b) non-uniform (c) zero (d) infinity

3. The three electric vectors D , E and P are connected by the relation

(a) D= e0E+P (b) D= e0E-P (c) E= e0D+P (d) P= e0E+D

4. The ratio of the polarization of a linear dielectric to the local electric field is

(a) atomic polarisability (b) electronic polarisability

© molecular polarisability (d) oriental polarisability

II. 5. Which of the following equations is correct where the letters have the usual

meaning

(a) F= qv×B (b) B= qv×F (c) v= qB×F (d) B= qF×v

6. The cyclotron frequency is directly proportional to

(a) B (b) B2 (c) 1/B (d) 1/B2

7. The line integral of the magnetic field around any closed path is equal to

(a) zero (b) µ0I (c) µ0I2 (d) infinity

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8. Maximum power is transferred from a source to a load when the reactive

components of the impedances of the source and the load are

(a) zero (b) unequal (c) equal and opposite (d) equal and have same sign

III. 9. The electric intensity at a point close to a charged conductor of surface charge

density s is ___________.

10. The surface integral of the magnetic flux over a closed surface is _________.

11. In a parallel resonant circuit, the expression for the resonance frequency is

__________.

12. ____________ is used to reduce the strength of the current in an a.c circuit

without loss of power.


13. In a series LCR circuit the current is minimum at resonance.

14. Maximum power is transferred from a source to a load when the resistive

components of the impedances of the source and load are equal.

15. At resonance, a series LCR circuit behaves like a pure resistive circuit.

16. The force acting on a current carrying conductor placed perpendicular to a

magnetic field is zero.


17. State Gauss’s law in electrostatics.

18. State and explain Coulomb’s theorem.

19. Explain the term quality factor of a series LCR circuit.

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20. Give the principle and use of choke in an electric circuit.

21. Explain magnetic potential and flux density.

22. Why do we prefer a.c to d.c in the household power supply?

23. State and explain maximum power transfer theorem.

24. Calculate the power in an a.c circuit with L and R.

25. What are polar and non-polar dielectrics?

26. State and explain Ampere’s circuital law.

27. Briefly explain a parallel resonant circuit.

28. Explain the physical significance of Maxwell’s equations.


29. The dielectric constant of a medium is 4 and the electric field in the dielectric

is 106 V/m. Calculate the electric displacement and polarization.

30.Find the drift velocity of the conduction electrons in a copper wire of cross

sectional area 1.5×10-6 m2, carrying a current of 2 A. The density of copper is

8.95 gm/cc and atomic mass is 63.5

31. A proton enters a magnetic field of flux density 2.5 T with a velocity of

1.5×107 m/s at an angle of 300 with the field. Calculate the force on the proton.

32. An electron accelerated by a potential difference of 5000V enters a uniform

magnetic field of 0.02 Weber/m2 perpendicular to its direction of motion. Find

the radius of the circular path of the electron.

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33. The magnetic energy stored in an electromagnet is 480J when a current of 5A

is passed through its coil. Find the average e.m.f induced if the current is

reduced to zero in 0.5 second.

34. A coil of inductance 0.05H and resistance 200 O is connected to a 230V, 50Hz

a.c supply. What is the peak value of the current in the coil?

35. A resistance of 20O and a coil of inductance 0.02H are connected in series

with a capacitance and put across a 220V, 50Hz supply. Calculate the

capacitance so that the circuit resonates.

36. Find the power consumed in a circuit having a resistance of 50O in series with

an inductive reactance 75O, both being in series with an A.C. peak current of

1A and peak voltage of 220V.


37. State and prove Gauss’s law in electrostatics. Derive an expression for the

electric intensity due to uniformly charged sphere at a point outside, on the

surface and inside the sphere.

38. Explain magnetic vector potential. Derive an expression for the magnetic

vector potential of a current loop.

39. A parallel LCR circuit is connected across an a.c source. Deduce an

expression for the total current in the circuit and explain how it depends on the

applied frequency. Obtain an expression for the resonant frequency.

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PY1541 –Classical Mechanics and theory of Relativity Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE]

I.1. The number of degrees of freedom for a circular disc rolling on a horizontal plane

is (a) One (b) Six (c) Four (d) Three

2. A particle is forced to move on a sphere centered at the origin of a Cartesian frame

of reference. The constraint is

(a) Holonomic (b) Rheonomic (c) Non-holonomic

(d) None of these

3. If Hamiltonian does not involve a particular coordinate qk, such coordinate is

called

(a) cyclic (b) fictious (c) both cyclic and fictious (d) None of these

4. For a charged particle in an electromagnetic field the canonical momentum are

(a) mv2/2-eA/c (b) mv-eA/c (c) mv2/2-eA/c (d) mv+eA/c

II 5. A central force always conserves

(a) Energy (b) Linear momentum (c) Angular momentum

(d) None of these

6. For repulsive inverse square forces, the shape of the orbit is

(a) Hyperbolic (b) Elliptical (c) Circular (d) All of these

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7. The frame of reference attached to the earth is

(a) Inertial (b) non-inertial (c) accelerated (d) fixed

8. The Coriolis force is zero at

(a) Equator (b) north pole (c) south pole (d) none of these

III. 9. In the northern hemisphere the direction of the Coriolis force on a body moving

eastward is ___________.

10. The number of degrees of freedom for a rigid body with fixed point is

___________.

11. The Lagrangian of a simple pendulum of mass m and length l is ___________.

12. A physical system is invariant under rotation about a fixed axis, then

____________ is conserved.


13. The generalized coordinates of a system need not necessarily have the same

dimension.

14. Tachyons have velocity greater than that of photons.

15. Conservation of energy is due to homogeneity of space.

16. Motion of a particle under the force –kr obeys Kepler’s third law.


17. What is Coriolis force?

18. What does homogeneity of time mean? What is its consequence?

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19. What is inverse square law of force? Give two examples.

20. Distinguish between laboratory and center of mass systems.

21. What are generalized coordinates? What is its advantage?

22. Obtain the Lagrangian for a simple pendulum.

23. How is the negative result of Michelson-Moreley experiment explained?

24. Explain space like and time like intervals.

25. What are tachyons?

26. State D’Alembert’s principle.

27. Explain the concept of four-vectors.

28. Distinguish between conservative and non-conservative forces with examples.


29. The kinetic energy of a system with generalized coordinate q is 1/2Mq’2 and

its potential energy is ½(q2/C), where M and C are constants. Set up the

Lagrangian and hence Lagrange’s equation for the system.

30. The eccentricity of the earth’s orbit is 0.0167. Calculate the ratio of maximum

to minimum speeds of the earth in its orbit.

31. The Hamiltonian of a system is H= 1/2m (Px2+P y

2+Pz2) +mgz. Use Hamilton’s

equation to show that x’’=1, y’’=0 and z’’=-g.

32. A rod has a length of 1 m. It is moving in a spaceship with a velocity of 0.4c

relative to the earth. Calculate its length as measured by an observer (i) on

space ship and (ii) on the earth.

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33. A stationary body explodes into two fragments each of mass 1 kg that move

apart at speeds of 0.6c relative to the original body. Find the mass of the

original body.

34. A thin meter stick is projected into space with a velocity 0.3c such that its

length is oriented at 300 with the direction of motion. Calculate the apparent

length as measured by a stationary observer.

35. A particle describes a circular orbit under the influence of an attractive central

force directed towards a point on the circle. Show that the force varies as the

inverse fifth power of the distance.

36. Find the change in the value of energy when the problem of a two, one-body

system interacting through gravitational force is reduced to an equivalent one

body case.


37. State and prove Kepler’s laws of planetary motion.

38. Obtain the kinetic energy in the lab and the center of mass systems and hence

show that the kinetic energies of two colliding particles in center of mass

system are inversely proportional to their masses.

39. Derive the Lorentz transformation equations.

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Model Question Paper PY1542 –Quantum Mechanics


I. Choose the correct answer

1. Photoelectric effect was discovered by

(a) Newton (b) Einstein (c) Fermi (d) Max Planck

2. A perfect black body gives

(a) continuous spectrum (b) line spectrum (c) band spectrum (d) none of the above

3. The concept of matter waves was first put forward by

(a) Heisenberg (b) Schrödinger (c) de Broglie (d) none of the above

4. According to Bohr the non radiating orbits are called

(a) elliptical orbits (b) circular orbits(c) stationary orbits (d) none of the above

II. Name the following

5. Write down the Hamiltonian operator

6. Name the principle in quantum mechanics, which explains the non existence of

electrons inside the nucleus

7. Write down the canonical commutation relation

8. Write down an example for barrier penetration problem

III. Fill in the blanks

9. According to Einstein electromagnetic waves consists of tiny packets of energy

called ____________

10. Photoelectric work function depends on the nature of __________

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11. Zero point energy of particle in a box is a manifestation of ________ principle

12. Expectation value of velocity is equal to the time derivative of the expectation

value of ___________


13. Confirmation of particle nature of radiation was provided by Compton effect.

14. Group velocity of the wave packet is same as that of the phase velocity.

15. Eigen functions belonging to distinct eigen values are orthogonal..

16. Wave functions live in Hilbert’s space.


17. State and explain Bohr ’s correspondence principle.

18. Briefly outline the mechanism by which photoelectrons are emitted

19. Outline the statistical interpretation of the wave function

20. Briefly explain expectation value

21. Write a short note on ladder operator.

22 Write a short note on wave packet

23. Briefly explain the delta function well

24 .What do you know about momentum space

25. What do you understand by reflection less potential

26. Briefly explain determinate states

27. What is a linear operator?

28. What is Ehrenfest’s theorem?


29. Suppose a particle starts out in a linear combination of just two stationary states:

? (x,0)= C1 ? 1(x)+C2? 2(x).Assume that the constants Cn(x) and states ? n(x) are

real. What is the wave function ? (x, t) at subsequent times? Find the probability

density and describe it’s motion?

30.. Find the expectation value of the potential energy in the nth state of the harmonic

oscillator.

31. A particle of mass m is bound in the delta function well V(x) = -ad(x). What is the

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probability that a measurement of its momentum would yield a value greater than

p0 = ma/?

32 An electron has a speed of 500m/s. with an accuracy of 0.004%. Calculate the

certainty with which we can locate the position of the electron.

33. If A and B are Hermitian operators, show that (AB + BA ) is Hermitian and (AB-

BA) is not Hermitian.

34. Determine the de Broglie wavelength of an electron that has been accelerated

through a potential difference of 100 V.

35. A particle constrained to move along x axis in the domain 0=x=L has a wave

function

? (x) = sin (npx/L)where n is an integer. Normalize the wave function and evaluate

the expectation value of its momentum.

36. If the wave function for a system is an eigen function of the operator associated

with the observable show that <An >= <A>n.


37 Derive time independent Schrödinger equation. Explain stationary states.

38. Using operator method obtain eigen functions and eigen values of the linear

harmonic oscillator.

39. Prove the generalized uncertainty principle and explain the result.

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Model Question Paper PY1543 –Electronics


I. 1. High ripple factor means a) large amount of ac filtering b) small amount of ac filtering c) high voltage regulation d) small voltage regulation

2. Zener diode mainly act as a) rectifier b) voltage divider c) regulator d) filter

3. The ripple factor of a bridge rectifier is a) 1.21 b) 2.42 c) 0.48 d) 0.96

4. The forward amplification factor (ßdc) in CE configuration is a) IC / IE b) IC / IB c) IE / IB d) IB / IE

II. 5. The dc load line of a transistor circuit a) has a negative slope b) is a curved line c) gives graphic relation between IC and IB d) does not contain the Q-point

6. The smallest of the four h-parameters of a transistor is a) hi b) hr c) ho d) hf

7. A common collector amplifier has the highest a) voltage gain b) current gain c) power gain d) output impedance

8. Maximum overall percentage efficiency of a transformer coupled class-A amplifier is

a) 78.5 b) 25 c) 50 d) 85 III. 9. Negative fee back in a n amplifier

a) lowers its lower 3dB frequency b) raises its upper 3dB frequency c) increases its bandwidth d) all of the above

10. A Colpitts oscillator uses a) tapped coil b) inductive feedback c) tapped capacitance d) no tuned LC circuit

11. In amplitude modulation 100% modulation is produced when carrier a) frequency equals signal frequency b) frequency exceeds signal frequency c) amplitude equals signal amplitude d) amplitude exceeds signal amplitude

12. The channel width of VHF band in an FM broadcast is a) 75 b) 25 c) 88 d) 200

IV. 13. FETs have similar properties to a) PNP transistor b) NPN transistor c) thermionic valves d) unijunction transistors

14. In an E-only MOSFET, drain current starts only when VGS(th) is a) positive b) negative c) zero d) greater than VGS(th)

15. The semiconductor device acts like a diode and two resistors is

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a) SCR b) triac c) diac d)UJT 16. After firing an SCR, the gating pulse is removed. The current in the SCR will

a) remains the same b) immediately falls to zero c) rises up d) rises a little and then falls to zero


17. What is a diode? Draw the equivalent circuit of a crystal diode? 18. Draw the input and output characteristics of CB configuration? 19. Define ß. show that ß = a /(1- a) 20. What do you understand by transistor biasing? 21. Explain the following terms (i) frequency response (ii) decibel gain. 22. State the Barkhausen condition for sustained sinusoidal oscillation. 23. Explain the principle of tunnel diode? 24. What do you mean by the process of modulation? 25. Explain with diagram the pinch off phenomenon in an n-channel FET 26. Explain the condition of balance of a Wien bridge oscillator 27. Briefly describe a super heterodyne AM receiver. 28. Explain the working a LED. Give two applications.


29. A bridge rectifier uses 4 identical diodes having forward resistance of 5 O

each. Transformer secondary resistance is 5 O and secondary voltage is 30 V (rms). Determine the dc output voltage for Idc = 200 mA and rms value of the output ripple voltage.

30. An npn transistor circuit has a = 0.985 and VBE = 0.3 V. If Vcc = 16 V calculate R1 and Rc to place Q point at Ic = 2 mA, VCE = 6 volts.

31. The overall gain of a multistage amplifier is 140. When negative feedback is applied, the gain is reduced to 17.5. Find the fraction of the output that is feed back to the input.

32. For the optimally–biased transformer coupled class-A amplifier, maximum collector current change is 100mA. Find the power transferred to a directly coupled 4O speaker load.

33. The data sheet for a certain E-MOSFET gives ID = 4.5 mA at V GS = 12.V and VGS(th) = 6 V. Determine the value of ID for VGS = 10 V.

I1

I2

R2=20KO 2 KO

VBE

IB R1

Rc

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34. The summing amplifier as shown in fig. has R0 = 10 KO, R 1 = 10 KO, R 2 = 2.2 KO and R 3 = 3.3 KO. If V1 = 6 V, V2 = -3 V, V3 = 0.75 V find V0.

35. Draw the load line of the Si transistor in CE mode as shown in figure and assuming that ßdc = 80, calculate the Q point. Neglect ICO. Calculate the value of RB required to drive the transistor just in to saturation.

36. A 10 V regulated dc supply of 10 mA is required from a dc source of 12 – 15 V

by using a pair of zener diodes. Assuming Iz (min.) = 0.2 mA, design the circuit.


37. Explain the working of a full wave rectifier with a neat diagram. Derive an expression for efficiency and ripple factor of a full wave rectifier.

38. Describe the working of a single stage CE amplifier. Deduce an expression for voltage gain of a CE amplifier.

39. Draw the block diagram of an OP AMP showing the four major steps. With a circuit diagram describe an expression for the voltage gain of an inverting OP AMP

V1

V2

V3 V0

R0

R1

R2

R3-

+

VBB

RB = 47 KO

RC = 1 KO

VCC = 20 V

25


Model Question Paper PY1544 –Ato mic and Molecular Physics

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I 1. The minimum energy required to ionize hydrogen atom from its ground state

is about

(a) 13.6eV (b) 1.36eV (c) 0.136eV (d) 136eV

2. The radius of a hydrogen atom in its ground state is

(a)10-4cm (b) 10-6cm (c) 10-8 (d) 10-10cm

3. The doublets observed in alkali spectra are due to

(a)screening of the K-electrons (b) spin-orbit interaction of the electron

(c)pressure of isotopes (d) none of these

4.The selection rule for orbital quantum number for the electric dipole transition

in a single electron atom is

(a)? l=0,±1 (b) ? l=0 (c) ±1 (d) ?l=+1

II 5. Pure rotational spectrum of a diatomic molecule consists of

(b) two equally spaced lines (b) three equally spaced lines

© many equally spaced lines (d) no regular pattern

6. Multiplicity of the state 2D3/2 is given by

(a)1 (b) 2 (c) 3 (d) 4

7. The total energy of an electron in any stationary orbit is

(a)negative (b) positive (c) zero (d) uncertain

8. The de-Broglie wavelength associated with neutrons in thermal

26

equilibrium with matter at 300K

(a)1790A (b) 179A (c) 17.9 A (d) 1079A

III. 9. The Bohr magneton is of the order of

(a) 10-23 erg/gauss (b) 10-20 erg/gauss (c) 10-25 erg/gauss (d) none

10. Pauli’s exclusion principle states that

(a)Two electrons can have all the quantum numbers same

(b). No two electrons can have all the quantum numbers same

©. Particles with integer and half integer spin cannot exist in the same

state

(d). None of the above

11. The J value of the state 6H5/2 is

(a) ½ (b) 3/2 (c) 5/2 (d) none

12.The velocity of an electron in the first Bohr orbit is

(a) (1/137 )c (b) 137c (c) (1/1370)c (d) 1370c

IV. State whether the following statements are true or false

13. The aim of Stern and Gerlach experiment was to verify the validity of

vector atom model

14. X-rays are electromagnetic radiations of longer wavelength.

15. Vibrational Raman spectra can be used to study the structure of a diatomic

molecule

16. The spin quantum number of an electron can have only half integral values.


17. State and explain Pauli’s exclusion principle.

18. What is meant by spatial quantization?

27

19. What is Stark effect?

20. Distinguish between prolate and oblate symmetric top molecules.

21. Explain the effect of isotopic substitution on the rotational spectrum of

molecules.

22. Why are anti-Stokes lines more intense than Stokes lines?

23. What is isomer shift?

24. What is Duane Hunt limit?

25. Write a short on spectral term and spectral notation.

26. What is the principle of Mossbauer Spectroscopy?

27. Briefly explain Frank-Condon Principle.

28. Distinguish between continuous and characteristic X-ray spectrum.


29. The term symbol of the ground state of sodium is 32S1/2 and that of its first excited

state is 32P1/2. List the possible quantum numbers n, l, j and m j of the outer electrons

in each case.

30. The experimental value of Bohr magneton is 9.21×10-24 J/T and Planck’s constant is

6.625×10-34 J s. Calculate the charge to mass ratio of the electron.

31. The average spacing between adjacent rotational lines of CO molecule is 386.26 m-1.

Calculate the length of the CO bond. Isotopic mass of C12 = 0.012 Kg/mole, isotopic

mass of O16 = 0.016 Kg/mole and Avogadro number is 6.022×1023/mole.

32. In an experiment with Benzene, the wavelength of a pair of Stokes and anti-Stokes

lines were measured to be 4554 A0 and 4178 A0 respectively. Calculate the

wavelength of the corresponding infrared absorption line.

28

33. Calculate the critical voltage required to stimulate the emission of the characteristic

lines of the K-series in tungsten if the K-absorption edge is 0.178 A0.

34. Calculate the wavelength separation between the two component lines which are

observed in the normal Zeeman effect. The magnetic field used is 0.4 Weber.m-2. The

specific charge is 1.76×1011 C/kg and ?= 600 nm.

35. Irradiation of CCl4 by 4358 A0 radiation gives Raman lines at 4400 A0, 4419 A0, and

4447 A0. Calculate the Raman shift for each of these lines.

36. The microwave spectrum of HI molecule consists of a series of equidistant lines with

a spac ing of 12.8 cm-1. Calculate the bond length.


37. Explain rotation-vibration transition and P and R branches of the spectrum of a

diatomic molecule.

38. Describe, with necessary diagram, the Stern-Gerlach experiment. Explain its

significance.

39. What is the principle of NMR? Explain NMR spectrometer. Discuss any three

applications of NMR.

29


Model Question Paper PY1641 –Solid State Physics


I 1. The volume of primitive unit cell of a fcc structure with lattice constant ‘a’ is

(a) a3 (b) a3/2 (c) a3/4 (d) a3/8

2. Which of the following has hydrogen bonding

(a) CH4 (b) C (c) HF (d) CsCl

3. Which of the following has least packing fraction

(a) simple cubic structure (b) bcc structure (c) fcc structure

(d) diamond

4. The angle between any two of the lines joining a site of the diamond structure

to its nearest neighbour is

(a) 600 (b) 900 (c) cos-1(1/3) (d) 1200

II 5. Laue diffraction pattern is obtained using

(a) Characteristic X-ray (b) White X-ray (c) Monochromatic X-ray

(d) Filtered X-ray

6. 2D lattice with highest rotational symmetry is

(a) Square lattice (b) Hexagonal (c) Honey comb (d) Triangular

7. Which of the following solids always opaque to visible radiation

30

(a) Metallic (b) Covalent (c) Ionic (d) Vander Waals

8. Identify which one is simple cubic structure

(a) Sodium (b) Cesium (c) Polonium (d) Copper

III 9. For a superconductor, the susceptibility is _________

10. A crystallographic plane has the intercept 1 along a, 2 along b and 3 along c. A

parallel plane to this plane will have Miller indices ________

11. The co-ordination number for bcc structure is _________

12. Thermal neutrons of kinetic energy 0.02 eV undergo diffraction from a

(1 0 0) crystal plane. If the Bragg spacing is 2 A0 and the mass of neutron is

1.00898 amu, the angle of first order diffraction maximum is ________


13. Laue spots are generated when monochromatic X-ray fall randomly on a single

crystal.

14. X-rays can be deflected by electric and magnetic field together.

15. The crystalline solid has long range positional and rotational order.

16. Simply connected superconductor is solid sphere.


17. Define the following terms in relation to crystal structure. Crystalline,

polycrystalline and amorphous states of matter.

18. Distinguish between co-ordination number and number of atoms per

unit cell. Obtain them for sc, bcc and fcc structure.

19. What are the main sources of electrical resistance in metals? How does

it vary with impurities and temperature?

31

20. Show that Hall coefficient is independent of applied magnetic field and

is inversely proportional to current density and electronic charge.

21. Explain the phenomenon of magneto-resistance.

22. What is Ferro electricity? Give two examples.

23. What is photoconductivity? How does it arise?

24. Distinguish between ferromagnetism and anti-ferromagnetism.

25. Highlight the significance of critical current density in

superconductivity.

26. Give two differences between dislocations in sc and fcc lattices.

27. Explain Bragg’s law in X-ray diffraction.

28. What is Meissner effect? SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.]

28. Calculate the lengths of intercepts made by crystal planes having Miller

indices (2 1 3) and (0 1 0) in a crystal which primitive translation vectors 2.5

A0. What are their inter-planer spacing?

29. Calculate the compressibility of NaCl assuming a repulsive potential of the

form B/R9 acting between the nearest neighbours. The nearest neighbour

distance is R=2.81 A0 and corresponding A=1.7476.

30. Find the diameter of the largest atom that would fit into the void in nickel

without distortion.

31. Show that for an ideal hcp structure where atomic spheres touch each other,

the ratio c/a= (8/3)1/2.

32. An aluminium crystal is bent into a radius of curvature 5 cm. What is the

minimum dislocation density in the material?

32

33. Calculate the glancing angle of (1 1 1) plane of a cube rock salt (a= 2.81 A0)

corresponding to the second order diffraction maximum for X-rays of

wavelength 0.71A0.

34. The electrical and thermal conductivities of silver at 200C are 6.2×107 ohm -

1m-1 and 420 Wm-1k-1 respectively. Calculate the Lorentz number.

35. Calculate the critical current that can flow through a long thin

superconducting wire of aluminium of diameter 10-3m.The critical field for

aluminium is 7.9×103 A/m.


37. Outline classical Langevin’s theory of diamagnetism.

38. What is normal tunneling? Describe Josephson effect.

39. Based on Fermi-Dirac statistics, state the nature of the Fermi distribution

function. How does it vary with temperature?

33



PY1642 –Nuclear and Particle Physics Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE]

I 1. The sun release energy by (a) nuclear fission (b) nuclear fusion (c) spontaneous combustion (d)

hydrothermal process 2. The primary cosmic rays are composed of very energetic

(a) electrons (b) mesons (c) protons (d) neutrons 3. The scintillation counter (a) is not used for counting alpha particles (b) counts only gamma rays (c) it counts only beta particles (d) uses a material which emits light when a charged particle strikes it 4. a-particles consist of (a) 1 proton and 1 neutron (b) 2 protons and 2 neutrons © 2 protons and 1 neutron (d) 1 proton and 2 neutrons II 5. The reciprocal of the decay constant of a radioactive substance is called (a) Half life (b) Mean life (c) Total life (d) None of the above 6. Which of the following is the strongest? (a) Nuclear force (b) Electrostatic force (c) Gravitational force (d) Magnetic force 7. ß-particles are (a) Electromagnetic radiations (b) electrons (c) protons (d) helium nuclei 8. Which of the following is a fermion? (a) Electron (b) neutron (c) a -particle (d) none of these III 9. Electron and positron combine to form ___________. 10. The number of ion pairs produced per unit distance in an ionization

chamber is known as ___________. 11. Nuclear fusion reactions are also called __________ reactions. 12. The working of an atom bomb is based on the principle of __________.


13. Gamma radiations are electromagnetic radiations of high frequency. 14. The mass of an electron is entirely due to its charge. 15. Leptons have only integral spins. 16. The bubble chamber is sensitive only to particles of high ionizing ability.


17. Sketch a plot of binding energy per nucleon versus mass number and mention

its features.

34

18. “Nuclear forces saturate” – Comment.

19. What is transient radioactive equilibrium?

20. Explain nuclear quadrupole moment.

21. Explain the principle of GM counter.

22. Define Q value of a nuclear reaction.

23. What is a breeder reactor?

24. On the basis of a liquid drop model, account for the fission of a nucleus.

25. Distinguish between mesons and baryons.

26. What are quarks?

27. Write a short note on radio-carbon dating.

28. Explain the thermonuclear reactions taking place inside the sun.


29. Given the following isotopic masses. Calculate the binding energy of a

neutron in the 3Li7 nucleus.

3Li7= 7.016004 amu; 3Li6=6.015125 amu; 0n1 =1.008665 amu.

30. The half life period of C14 is 5570 years. How long does it take for 80% of

radioactive C14 to decay?

31. Calculate the Q value of the reaction, 1H2 (d, n) 2He3. Given, mass of

1H2=2.0141 amu; mass of 2He3= 3.01603 amu; mass of 0n1=1.008665 amu.

32. A nuclear reactor using U235 as fuel is designed to deliver 100 MW. What is

the mass of U 235 required per day assuming 100% efficiency? Given that a

35

single U235 atom releases 200 MeV energy.

33. Check whether the following reaction is allowed on the basis of conservation

laws. p + p¯ ? 2p+ + 2p - + 2p 0

34. A cyclotron of maximum radius 0.25 m accelerates protons in a 2T magnetic

field. Calculate the frequency needed for the applied ac voltage. Also evaluate

the kinetic energy of the protons when they leave the cyclotron.

35. A high energy singly ionized particle leaves a track of 2 m radius in a cloud

chamber placed in a magnetic field of flux density 2.5 Wb m-2. Calculate the

energy of the particle.

36. A sample of energy of uranium 4.18 MeV and is placed near an ionization

chamber. Assume that 10 particles enter the chamber per second and 35 eV is

required to produce an ion pair. Calculate the current produced.


37. Describe the important features of ß ray spectrum emitted by radioactive

nuclide. Outline the neutrino theory of ß decay. How does it explain the

continuous energy spectrum in ß decay?

38. Give the principle of nuclear reactor. What are the roles of moderator and

control rods in the reactor? List the main parts and explain the working of the

reactor.

39. Distinguish between primary and secondary cosmic rays. Explain cosmic ray

showers. Explain the latitude and altitude effects of cosmic rays.

36


Model Question Paper PY1643 –Classical and Modern Optics


I 1. The defect of a lens that arises due to the dependence of its focal length on its

thickness and diameter is

(a) Chromatic aberration (b) Coma (c) Astigmatism (d) Distortion

2. Two light waves of amplitude ‘a’ and ‘2a’ superimpose each other. The intensity

of a bright band is

(a) a2 (b) 2a2 (c) 3a2 (d)9a2

3. The wavefront due to a distant object is

(a) Spherical (b) Plane (c) Cylindrical (d) None of these

4. The resolving power of a diffraction plane grating having N lines/cm in the nth

order is

(a) n/N (b) N/n (c) Nn (d) N2n

II. 5. Fringes of equal inclination are also called ___________.

6. Polaroids work on the principle of ___________.

7. The three dimensional photograph of an object is called ___________.

37

5. In fiber-optic communication, _________ is used as the carrier wave.

III. State whether the following statements are true or false.

9. Laser beam is highly directional.

10. Holography provides a high capacity system for image storage.

11. The pulse dispersion in a step index fiber is less than that in a graded index

fiber.

12. A quarter wave plate can be used to produce circularly polarized light from

plane polarized light.

IV. Match the words in column A with a suitable word in column B

A B

13 Interference Waves of the same wavefront

14 Dispersion Coherent sources

15 Diffraction Snell’s law

16 Refraction Colour formation


17. Explain how coherent sources are realized in practice.

18. What are Newton’s rings?

19. Draw a well labeled diagram of Michelson’s interferometer.

20. Explain the difference between Fresnel and Fraunhofer diffraction.

21. How will you obtain plane polarized light by reflection?

22. Distinguish between normal and anomalous dispersion.

38

23. What are single mode fibers? Why are they so called?

24. Give four applications of holography.

25. Explain the term line shape function.

26. What are coherent bundles?

27. Define resolving power of a grating.

28. Distinguish between a quarter wave plate and a half wave plate.


29. A plane transmission grating has an angle of diffraction 200 for light of

wavelength 600 nm in the first order. Calculate the number of lines per cm of

the grating.

30. Angle of polarization for water is 53.10. Calculate the refractive index of water

and angle of refraction.

31. Numerical aperture of optical fiber is 0.295 and refractive index of core is

1.54. Calculate the refractive index of cladding.

32. Monochromatic light of wavelength 589.3 nm is incident normally on a thin

wedge shaped film of transparent plastic of refractive index 1.42. Interference

fringes are observed in reflected light. If the distance between adjacent bright

fringes is 0.26 mm, find the angle of the wedge.

33. Calculate the Cauchy’s constants A and B for a glass prism of refractive index

1.5228 for light of wavelength 546.1 nm and refractive index 1.5373 for a

wavelength 404.7 nm.

39

34. Find the relative population of the two states in a ruby laser that produces a

beam of wavelength 694.3 nm at 300 K. Boltzmann’s constant is 1.38×10-23

J/K.

35. What is the radius of the first zone in a zone plate of focal length 0.2 m for

light of wavelength 500 nm?

36. Two polaroids are first crossed and then one of them is rotated to reduce the

intensity half and one fourth. Calculate the angles rotated.


37. With the help of a neat diagram explain how Newton’s rings are formed in the

reflected system. Obtain the relation between D, R and ? where the symbols

have usual meaning.

38. Describe the construction of Nicol prism. Explain how it is used as a polarizer

and as an analyzer.

39. Explain the working of Helium-Neon laser highlighting population inversion

mechanism.

40


Model Question Paper PY1644 –Computer Science

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I.

1.The binary number system has a base of

a. 10 b. 16 c. 2 d. 8

2.The result after converting number 3510 to hexadecimal

a. 2316 b. 8D 16 c. AE 16 d. 5316

3. The output of an AND gate with inputs A, B and C is 1 when

a. A=1,B=1,C=1 b. A=0,B=1,C=1 c. A=1,B=0,C=1 d. A=0,B=0,C=0

4. The ALU of a computer responds to the commands coming from

a. Primary memory b. Control section c. External memory d. Cache memory

II. 5. Semiconductor memories are fabricated using ____ technology

a. SSI b. VSLI c. LSI d. MSI

6. The maximum memory location that a 16bit computer can address

a. 64 b. 64k c. 32k d. 128

41

7. A GUI is

a. hardware b. language interpreter c. software interface d. an operating system

8. Which of the following would cause quickest access

a. direct access from a magnetic tape b. direct access from a hard disk c. direct access from a floppy disk d. direct access from a cassette tape

III. 9. Multiprogramming refers to ____

a. having several programs in RAM b. multitasking c. writing program in multiple languages d. none of the previous

10. Assume x=5, what value will be stored in result in the statement :– result = x%2; a. 10 b. 2.5 c. 2 d. 1

11. How many types of arithmetic operations does the ALU of all computers perform?

a. 3 b. 2 c. 5 d. 4

12. Reading consists in the value which lies between two extreme points means

a. Exploration b. Interpolation c. Extrapolation d. None of these


13. The 1’s complement of a binary number is derived by changing 1s to 0s and 0s to 1s.

14. Half adder is a logic circuit that adds two digits at a time.

15. The assignment statement : 72 = amount; is valid.

16. A semicolon may follow an if statement only if a compound

statement is used.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.] 17. What is 2’s complement? How to obtain 2’s complement? 18. Define associative and distributive laws of Boolean algebra. 19. What is the purpose of ALU in CPU? 20. What is ASCII code? Write any four ASCII codes and corresponding characters.

42

21. What are the basic rules of binary addition and binary subtraction? 22. Define Flip-Flop. Describe briefly its function and application. 23. Define impact and non impact printers. 24. Describe the Linux operating system. 25. Write C statement for the following. [a] p = , [b] g =

26. What will be the output of the following program? Modify the program to obtain the same result by replacing with a while loop main() { int i; for(i=1; i<=10; i++) printf(“%d”, 5*i); } 27. Compute the value for the following expressions. a. x = 4+5*(10-2)

b. k = (17-6)%2-1 c. n = 20 + 5%3-1

28. What do you mean by linear interpolation? SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29. Using 2’s complement method perform A-B with:

a. A=1000100 and B=1010100 b. A=11011 and B=01101

30. Solve the following X10 = 101.11012 X16 = 1100101001010111 X2 = 17510 X2 = 3816 31. Design a NAND gate, using two inverters and one OR gate, whose output is given by Boolean expression Y = 32. Implement XOR function using 4 two input NAND gate. 33. Perform the following operations using signed Arithmetic operations.

a. Add +5 decimal and -2 decimal b. Add -20 decimal and -18 decimal

34. Write a C program to determine whether a number is odd or even and print the message, NUMBER ENTERED IS ODD OR NUMBER ENTERED IS EVEN,

a. without else option b. with else option. 35. Write a program to calculate the focal length of a lens of a given refractive index and radii of curvature using lens makers formula. 36. Using Euler’s method find the approximation value of solution of the differential equation with the initial condition at points where x = 3.1, 3.2

and 3.3

43

SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37. What is CPU? Draw block diagram to illustrate the basic organization of a computer system and explain the functions of various units in detail. 38. What is a Flip-Flop? Describe a]. S.R.Flip Flop and b]. J.K.Flip Flop. What are the advantages of J.K Flip Flop and S.R Flip Flop? 39. What are the remarkable features of C language? Discuss with suitable examples, the different control statements available in C.


Model Question Paper PY1551.1 –Bio Physics (Open Course)


I. Choose the most appropriate answer

1. Continuity equation is (a) a1v1=a2v2 (b) a1p1=a2p2 (c) a1k1=a2k2 (d) a1r1=a2r2

2. Reynolds number is related to (a) Density (b) Viscosity (c) Plasma (d) Temperature 3. For an optical fibre refractive index of core n1 and that of clad is n2 then, (a) n2<n1 (b) n2>n1 (c) n2=n1 (d) None of the above 4. Birefringince is (a) Dichrosim (b) Double refraction (c) Refraction (d) Total internal reflection. II Name the following 5. What tends to contract muscles?

6. What are the physical parameters which depends characteristics of bone?

7. What is the principle behind optical fibre? 8. State continuity equation

III Fill up the blanks 9. Muscles are devices which apply necessary ________ 10. The work done by a muscle per unit mass of the muscle is called ___ 11. The physiological effect of impulse is sense of _______ 12. Resistivity of the flow channels is ________

44

IV State whether the following statement is True or False 13. Muscles are divided into two categories

14 The product force X velocity is known as fundamental equation of Muscle contraction. 15. Mechanical efficiency of berathing is the ratio of work done to total chemical energy

16. Human ear is a transducer

Section B (Answer any 8 questions – Each questions has a weigtage of 1)

17. State stokes law? 18. Name the three types of locomotion on land 19. What is meant by pitch? 20. Name the four media through which light travels in human eye 21. What is chromatic aberration? 22. State the features of Vander waals force 23. Give the characteristics of cell membrane 24. State first law of thermo dynamics 25. What is bioinformatics? 26. What is bio statics? 27. State continuity equation 28. State Fick’s law of diffusion


29. How muscles are classified? 30. What is mass specific muscle power? 31. Explain the strength of bones 32. Explain the three type of motion for locomotion on land? 33. Discuss the role of gravity in plant life 34. Explain the physiology of respiration 35. Discuss the behaviour of Doppler effect in human ear? 36. Explain plasma skimming effect.

Section D

(Answer any 2 questions – Each questions has a weightage of 4)

37. Explain the transport of O2 and CO2 in blood 38. What are proteins? Give the structure of protein. Explain the functions of

amino acids? 39. What is bio potentials? Explain the functions of dosimetry.

45


Model Question Paper PY1551.2 –Astronomy and Astrophysics (Open Course)



1. Olivine is a green mineral consisting of

(a) iron magnesium silicate (b) iron magnesium carbonate (c) silver magnesium

carbonate (d) iron carbon silicate

2. The first Pulsar was discovered by Jocelyn Bell in

(a) 1967 (b) 1958 (c) 1942 (d) 1962

3. Meteors are also called

(a) variable stars(b) binary stars (c) shooting stars (d) none of the above

4. The inclination of the axis of the earth from the normal to the orbital plane is

(a) 23° 26’ 28” (b) 23° 32’ 28” (c)32° 26’ 28” (d) 23° 26’ 42”


5. What is the full form of GMT?

6. Name the two small satellites of Mars

7. Name the largest satellite of Saturn

46

8. What is the total pressure of Venus’ atmosphere?

III. Fill in the blanks

9. The earth has ____________times the mass of Venus

10. Name origin of August is __________

11. Schwarzschild radius depends on ________ of black holes.

12. ___________ was the first to determine distance to the moon from earth


13. Sunspots are maintained by strong magnetic field.

14. Astronomers have classified the stars into spectral type identified by the letters

OBAFGK&L

15. Neutrons at the surface of a neutron star decays into protons and electrons.

16. Cepheids are visible with naked eye.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.] 17. Write a short note on scope of Astronomy

18. What do you know about Cepheids?

19. What are Zodiac nebulae?

20. Define Hubble distance

21. Write a short note on Photosphere of Sun

22.What are Constellations?

23. Define luminosity of a star.

24. What are black holes?

25. What are Asteroids?

26. What is sidereal period?

27. Briefly explain Chandrasekhar limit

28..What do you know about satellites of Uranus?

SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29 What is H-R diagram? Explain its main features?

30.. State and explain Kepler’s laws of planetary motion

31..Write short note on the latest discoveries about Pluto

32 Briefly discuss meteorites

33. What do you know about Supernova explosion?

47

34. Briefly discuss ring system of Saturn

35. Write short note on Comets.

36. Briefly discuss the features of the Planet Mars

Section D (Answer any two questions, each has a weightage of 4 )

37 Discuss modern Astronomy with necessary diagrams

38. Explain the structure, energy source and spectrum of Sun

39. What are Galaxies? Explain the different types of galaxies.


Model Question Paper PY1551.3 –Applied Physics (Open Course)

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I 1. The radio was invented by ……………………………………..

2. Cellular phone started operation in India in …………………….

3. The chemical coated on the top of an audio cassette is …………

4. In a digital camera the role of the film is substituted with ………

II 5.SEM is used for ……………………………………………........

(a) Surface morphological studies.

(b) Internal structure studies.

(c) Chemical composition studies.

(d) None of the above.

6. XRD is used for ………………………………............................

(a)Surface morphological studies

(b) Internal structure studies

(c)Chemical composition studies

(d)None of the above

48

7. The working principle of TEM………………………………….. (a)

Quantum Mechanical Tunneling

(b) Scattering

(c) Diffraction

(d) None of the above

8. In an electric fan ……………………………………………….

(a) Electrical energy is converted into Mechanical energy.

(b) Mechanical energy is converted into Electrical energy.

(c) No energy conversion.


III 9. In holography the light source used is …………………………

10. SIM stands for ……………………………………….. in a

Mobile phone

11. In an optical communication net work the medium of

communication is………………………………………………

12. The first electron microscope was built in ……..........................


13.4 Stroke engine is more efficient than

2 Stroke engine

14. The working principle of MRI scan & the ultrasound scan are

the same

15. Optical communication network needs amplifiers.

16. Spectrometer is used to study the polarization of light.


17. Explain the basic principle of scanning tunneling microscope

(STM)

18. List out the different type of pumps

19. How a digital camera differs from an ordinary camera?

20. Distinguish between CT scan & MRI scan

21. With the help of a block diagram, explain the working of a

Public Administration system (PAS).

49

22. Briefly explain the working of RADAR.

23. Distinguish between Tunneling Electron microscope (TEM) & Scanning

Electron microscope (SEM)

24. What do you mean by a compact Disc (CD)?

25. List out 5 applications of x-rays.

26. Explain the basic principle of working of a refrigerator.

27. Which are different types of breaks used in automobiles?

28. What is a spectro photo meter?

What is its use?


29. Explain the principle of LCD.

30. How ECG helps in the treatment of heart diseases.

31. Microscope resolving power problem.

32. Write a paragraph on the history of evolution of radio.

33. Write a short note on the revolution made by touch screen.

34. List of the technical specifications of the Atomic Force

Microscope( AFM )available in Indian market.

35. Explain the working of refrigerator.

36. Briefly explain the working of ATM

SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37. With the help of a schematic Diagram explain microscope

(SEM)

38. (a) Explain the theory & working of an electric fan.

(b) List out different type of fan available in the market.

39. With the help of block diagram make a comparative study of

cable of cellular phone system.

50


Model Question Paper PY1551.4–Environmental Physics (Open Course)


I. Choose the correct option 1. Lowest layer in atmosphere a) troposphere b) stratosphere c) mesosphere d) ionosphere 2. Global warming is caused by

a) Oxygen b) Nitrogen c) carbon monoxide d) carbon dioxide

3. This is a non-renewable form of energy a)hydro-lectric power b) solar energy c) petroleum d) solar energy

4. Noise in the context of sound pollution is measured in, a) ppm b) joule c) decibel d) watts

II. Choose the correct option 5. United nations general assembly has declared 2010 as the International Year of ...

a) climate change b) science c) astronomy d) biodiversity

6. Largest fraction of pure water on Earth is in the form of

a) water vapour b) ice c) water in lakes d) ground water

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7. Indian satellite used exclusively for remote sensing is

a) INSAT b) ASTROSAT c) IRS d) Chandrayaan

8. 'Rem' is a unit related to

a) water pollution b) noise pollution c) air pollution d) nuclear radiation

III. Match the following 9. Ozone a) solar power

10.radioactivity b) global warming

11. water quality c) ultra-violet

12. carbon dioxide d) nuclear power

e) pH value


13. Earth would have been freezingly cold if there was no green house effect. 14. Electricity generated from solar cells is cheaper than that produced by hydroelectric stations. 15. In India, installed capacity of windmills exceeds capacity of nuclear power stations.

16. Per capital pollution in India is much less than in U.S.A. SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.]

17.Write a short note on the composition of atmospheric air. 18. What is meant by hydrostatic equilibrium? 19. What are fuel cells? 20. Write a short note on monsoons. 21. What do you mean by bioenergy? 22. What is meant heat island effect? 23. What do you mean particulate matter? Give examples. 24. What do you mean by sustainable development? 25. Explain how land and sea breeze occur. 26. What do you mean by Kyoto protocol? 27. Comment on the statement “waste is misplaced wealth” 28. What is meant by "Green Revolution"?


29. Write short note on the thermodynamics of atmosphere. 30. Write a short note on the general circulation of the tropics. 31. What do you mean by air and water quality standards?

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32. Write a brief note on radioactive pollution. 33. Explain why we should conserve petroleum resources. 34. Point out the important limitations of hydropower. 35. Explain how deforestation leads to degradation of soil. 36. Explain the concept of "evergreen revolution" in agriculture.


37. Briefly describe the causes and effects of global warming. 38. Write an essay on waste management. 39. Discuss various renewable sources of energy.


Model Question Paper PY1551.5 –Energy Physics (Open Course)


I. 1. Which one of the following is a source of non-conventional energy? a) Coal b) Oil c) Gas d) Sun 2. Which of the following is not an example of a bio-mass energy source?

a) Wood b) Gobar gas c) Nuclear energy d) Coal 3. Which of the following is not ultimately derived from solar energy?

a) Geothermal energy b) Wind energy c) Nuclear energy d) Bio-mass energy

4. A solar water heater cannot be used to get hot water on a) Sunny day b) Cloudy day c) Hot day d) Windy day

II. 5. A solar cell converts solar energy into __________.

6. The source of energy in tidal power is the __________ between earth, moon and

sun

7. In a fuel cell electricity is stored in __________ form.

8. A single solar cell can produce a voltage of _______ in full sunlight.

III. Match the following

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9. Biomass energy a) Non-conventional

10. Geothermal energy b) Gobar gas

11. Solar energy c) Gravitation

12. Tidal energy d) Earth’s internal heat


13. Geothermal power is ultimately derived from solar power 14. The amount of energy from the sun and other renewable sources is very large compared with the amount of energy used by mankind. 15. Biomass fuels can provide a sustainable substitute for fossil fuels with no net carbon dioxide production.

16. Air transport is inherently energy intensive while rail and water are more energy efficient.


17. Describe the salient non-conventional resources of energy. 18. What are photovoltaic modules and arrays? 19. What is the principle of ocean thermal energy conversion? 20. What are the different types of coal? 21. Explain the principle of a solar cell. 22. What is the principle used in wind mill? 23. What is space cooling? 24. Explain how solar energy is used in solar ponds. 25. What are the important methods for energy storage? 26. Explain the advantages of biomass as energy source. 27. What are the photovoltaic systems commonly in use? 28. Explain ‘green house effect’.

SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO .]

29. Sketch the various stages of extraction of tidal energy. 30. What are the merits and limitations of waves as a source of energy? 31. Explain the effect of global warming. 32. Explain the working of solar furnaces. 33. Explain why the exciting radiation must incident very near the p-n junction in

a solar cell and not far away from it. 34. Describe the advantages of alternate energy sources. 35. Describe the applications of a solar cell. 36. What are the important sources of renewable energy?

SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR.]

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37. What is meant by power of wind? How the wind power is extracted using wind mill?

38. Describe the working of ocean thermal energy conversion (OTEC) plant. 39. Explain biomass conversion process. Describe the working of a gobar gas

plant.


Model Question Paper PY1651.1 –Electronic Instrumentation (Elective Course)

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I. Choose the most appropriate answer

3. An ammeter used to measure the reverse current of a Si diode is (a) Milli (b) Micro (c) Nano (d) Pico

4. The percentage change in magnitude of a Carbon resistor with gold tolerance band is

(a) 1% (b) 5% (c) 10% (d) 20% 3. Frequency of 50Hz a. c. can be used to measure using CRO with a time-base

of (a) 0.1ms (b) 10ms (c) 1ms (d) 0.1 s 4. A galvanometer can be used to (a) Measure current (b) Measure voltage (c) Detect and measure current (d) None of the above II Name the following 5. Name the circuit element used to design a delay line 6. What is an AVO meter?

7. Name the transducer element used in ordinary clinical thermometer 8. Give another name of function generator

55

III Fill up the blanks 9. A nano ammeter measure current of the order of _____ A 10. Quality factor of a circuit element is a _________ 11. CRO is used to obtain _______ ____________ of an electric signal 12. Harmonics present in a square wave signal can be obtained by the

_________ __________ IV State whether the following statement is True or False

14. A moving coil galvanometer can be used as ammeter or voltmeter 14 Instrumentation is basically measurement science or Metrology 15. CRO can be used to save a signal

16. LED is an opto electronic device

Section B (Answer any 8 questions – Each questions has a Weightage of 1)

17. What is meant by precision and accuracy? 18. What is meant by Q value of a given parameter? 19. What is meant by resolution of a D/A converter? 20. Give the relevance of delay line 21. Give the use of storage oscilloscope 22. Define deflection sensitivity of a CRO 23. What is a thermister? 24. Give the uses of radiation detector 25. Give the principle of instrumentation amplifier 26. Give the uses of sweep generator 27. What is a wave meter 28. Give a typical application for spectrum analyzer

Section C

(Answer any 5 questions – Each question has a weightage of 2)

29. Give the block diagram of DVM. Explain the function of each unit 30. Draw the block diagram of a CRO 31. How strain gauge can be used to measure temperature 32. Draw the circuit diagram of an astable multi vibrator, give its working. 33. Explain the function of a spectrum analyzer 34. Give the different types of standards of measurement 35. What are active and passive probes used for CRO give its merits 36. How Q value of a circuit element can be evaluated?

Section D

(Answer any 2 questions – Each questions has a weightage of 4)

37. With necessary block diagram explain the working of a CRO. Give the relevance of delay line circuit.

56

38. Using a thermister how it can be used to calibrate a given thermocouple for a given range of temperature

39. What is sample and hold circuit? How sweep circuit can be designed, give its uses.


Model Question Paper PY1651.2–Space Science (Elective Course)



1. Name of our Galaxy is

(a) Andromeda (b) Milky way (c) Pisces (d) Ursa Major

2. Mass of Sun is

(a) 1.99× 1030 Kg (b) 1.92×1020Kg (c) 2.5×1015 (d) 5.2×1030Kg

3. Visible surface of Sun is called

(a) Chromosphere (b) Photosphere (c) Corona (d) Sunspot

4. The sound speed in the Interplanetary medium is about

(a) 50 km/s (b) 100 km/s (c) 1000 km/s (d) 10000km/s


5. Name a X ray Astronomy satellite

6. Name the scientist who has observed CMEs at first

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7. Write down the full form of QUASAR

8. In the equation H = kT /mg , what does H indicate?

III. 9. The word red shift is used to indicate a shift to ____________end of visual

spectrum

10. The Plasma sphere extends between __________ to ____________ km.

11. The energetic particles originating from sources outside solar system are called

__________ cosmic rays .

12. Sun is said to be ___________ when very few sunspots are seen.


13. The stratosphere is found above the tropopause.

14. E layer of the Ionosphere disappears at night.

15. Sun is a red giant.

16. The magnetic field of earth is not steady but shows variation with time.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.] 17. What do you mean by Cosmology?

18. What are Pulsars?

19. What do you know about Harvard classification of Stars?

20. What are White dwarfs?

21. What do you know about Solar flares?

22. What are Van Allen belts?

23. Explain Scale height.

24. Explain how cosmic rays are originated.

25. What is Chandrasekhar limit? Explain.

26. Write short note on Photon diffusion time.

27. Write a brief note on our Galaxy

28..Give a brief account on different types of Galaxies

Section C (Answer any five questions, Each question has a weightage of 2)

29.. How do you explain expansion of the Universe?

30. Write short note on Chromosphere of Sun.

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31.. Give a brief account on disturbed Solar wind.

32. Explain Sunspots and Solar activity

33. Give a brief account on Dungey’s open magnetosphere.

34. What is H-R diagram? Explain its main features?

35. Give a brief account on the magnetic field of Earth.

36. Explain different layers of Earth’s ionosphere.

Section D (Answer any two questions. Each question has a weightage of 4)

37 What do you know about Solar Corona? Explain how Solar wind is originated?

38. Discuss Chapman’s theory of layer formation in Earth’s ionosphere

39. Describe nomenclature of Earth’s atmosphere on the basis of temperature

profile


Model Question Paper PY1651.3 –Photonics (Elective Course)

Time 3 hours Total weightage : 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE]

I. Choose the correct option 1. When a photon stimulates the emission of another photon the two photons have a) same energy b) same direction c) same phase d) same wavelength 2. The impurity atoms with which pure silicon may be doped to make it a p – type

material are a) Phosphorus b) boron c) antimony d) aluminium

3. In a semiconductor, a) there are free electrons at 0 K b) there are no free electrons at any temperature c) the number of free electrons increases with temperature d) the number of free electrons is less than that in a conductor.

4. The quantum efficiency of detector is a) less than zero b) greater than zero c) between one and zero d) complex quantity

II. Choose the correct option 5. Choose the correct statement

a) Responsivity increases with the frequency of incident radiation

b) Responsivity decreases with the frequency of incident radiation

c) Responsivity is independent of the frequency of incident radiation

d) Responsivity is equal to the frequency of incident radiation

59

6.Flicker noise is significant at frequencies

a) < 1kHz b) > 10kHz c) >100 kHz d) >1000 kHz

7. A Photodiode detector is usually given

a) forward bias b) reverse bias c) both d) no bias

8. The excitation energy required to excite an electron from donor level to conduction band is ______eV ( Given effective mass= 0.26 times the mass of electron and 1/? r =11.8

a) 2.5 b) 0.25 c) 0.025 d) 0.0025

III. Match the following

9. Bolometer a) Opto-isolators

10. Photodiode b) Modulators

11. Light source-detector package c) Quantum detectors

12. Light intensity variation occurs d) Connectors

e) Thermal detector


13. Silicon is a direct band gap material. 14. Silicon can be used for making laser sources. 15. Silicon can act as amphoteric dopant in GaAs

16. Silicon photo detectors have low dark current when compared to Germanium photo detectors.


17. What are excitons? 18. What is Auger recombination? 19. What do you mean by indirect bandgap semiconductors? 20. What is Kerr effect? 21. What is. Pockels effect? 22. What is meant by optical non linearity? 23. What is optical computing?. 24. What is noise in photodetectors? 25. How are liquid crystals classified? 26. What are the advantages of PIN photodiode? 27. What is the bandgap energy of the semiconductor material emitting

radiation at 600 nm? 28. What is optical pumping?


60

29. Write short note on optical bistability. 30. Write a short note on spatial light modulators. 31. What do you mean by self focusing? 32. Write a brief note on Schotky barrier photodiodes. 33. Explain the principle of semiconductor lasers. 34. Write short note on quantum well structures. 35. Calculate the internal quantum efficiency and bulk recombination lifetime

in the absence of reabsorption of photons and interface recombination (Given that the radiateiveand non radiative lifetimes of minority carriers in the active region of an LED are 2.5 and 90 nanoseconds respectively.

36. Calculate radiative recombination time in GaAs having equilibrium carrier concentration 1014 cm-3 under low level injections for Br= 7 x 10-10 cm3/s


37. A silicon PIN diode with R=0.65 A/W, Id= 1nA, RL= 1000 ohm is operating at 850 nm. If the incident optical power is 500 nW and bandwidth is 100MHz. Calculate 1) signal current 2) r.m.s short noise current due to signal 3) r.m.s thermal noise 4) signal to noise ratio.

38. Describe LED structure and efficiency 39. Write note on various optical switches.


Model Question Paper PY1651.4 –Concepts of nanoscien ce (Elective Course)

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] 1. Quantum dot is an example of _________ dimensional confinement.

a. one b. two c. three d. zero

2. What is grapheme? a. a new material made from carbon nanotubes b. one atom thick sheet of carbon c. thin film made of fullerenes d. none of these 3. Nanostructured materials are characterized by a. large surface to volume ratio b. low surface to volume ratio c. lower band gap c. none of these

61

4. Ball milling is a ______________ method to synthesize nanomaterials. a. top down b. bottom up c. natural d. novel 5. Which of the following can be estimated using X-ray diffraction

technique? a. average grain size b. conductivity c. mobility of the ion d. none of these

6. Which of the following techniques can be used for composition analysis? a. ICP b. XRD c. AFM d. TEM 7. Phonon is a quantum of

a. elastic wave b. electromagnetic wave c. polarization wave d. magnetization wave. 8. As a result of the grain size transforming to nano regime the band gap becomes a. wider b. narrower c. no change d. widens as the grain size decreases

9. Carbon nanotubes are characterized by a. high thermal conductivity b. diameter of the order of nanometers c. high mechanical strength d. all the above

10. A fuel cell does not “run down” like a standard battery because a. the reactants in a battery must be stored inside the battery whereas the reactants for a fuel cell flow in as needed. b. a fuel cell continually recycles the same electrons whereas a battery must continually generate new ones. c. a battery is completely dependent upon oxidation-reduction reactions whereas a fuel cell depends on acid-base reactions. d. a battery has many moving parts, whereas a fuel cell has none.

11. Broadening of Raman peaks found in nanomaterials is due to

a. non-validity of law of conservation of momentum in the case of nanosized grains

b. uncertainty principle c. Doppler effect d. None of the above 12. Carbon nanotubes can be synthesized using a. arc method b. sputtering c. ion implantation d. none of the above 13. Phonon confinement in nanomaterials results in a. shifting of Raman peak b. occurrence of surface modes c. broadening of Raman peak d. all the above. 14. UV-Visible absorption spectroscopy can be used to estimate the

62

a. band gap b. conductivity c. crystal structure d. none of these 15. The interconnects of nanoelectromechanical systems are

a. nanowires b carbon nanotubes c. Nanobelts d. Nanobots

16. Single electron transistors are characterized by a. low noise b low gain c. high resistance d. none of these

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE]

17. The emission energies of a luminescent semiconductor can be tailored in the

nano regime. Justify the above statement.

18. PbS nanocrystals of size 20 nm show quantum confinement effect while CdS

nanocrystals of the same size do not show it. Why?

19. The atomic force microscope (AFM) or scanning force microscope (SFM) is a

very high-resolution type of scanning probe microscopy, with demonstrated

resolution of fractions of a nanometer, more than 1000 times better than the

optical diffraction limit. Give an account of the advantages of this instrument

in the field of nanoscience and nanotechnology.

20. How ion implantation technique can be used to synthesize compound

semiconductor nanoparticles.

21. Mention the differences between Raman spectra of nanostructured materials

and their bulk counterparts

22. Nanomaterials show different properties compared to that of conventional

bulk materials. Can you substantiate this with the help of density of states plot.

23. The (m,n) indices for a carbon nanotube is given by (4,3). Find diameter and

chiral angle of the tube. Given rc-c = 1.421 Å.

24. Suggest a method to induce superconductivity in C60.

25. Coulomb blockade, named after Charles-Augustin de Coulomb, is the

increased resistance at small bias voltages of an electronic device comprising

at least one low-capacitance tunnel junction. Explain how this can be

observed.

26. What are the essential processes needed for the transition from micro MOS

transistor to nano MOS transistor.

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27. What will be the role of carbon nanotubes in nanoelectronics? 28. Explain the chief differences between an ordinary laser and quantum cascade

laser.


29. Briefly explain a method to synthesize nanostructured materials by top down

approach

30. List out the advantages and disadvantages of Transmission Electron

Microscope over X - ray diffraction technique in the characterisation of

nanostructured materials? If HRTEM pattern of a nanoparticle is given, how

will you interpret its phase and size?

31. Discuss how quantum confinement effect is manifested in the optical

properties of semiconductor nanoparticles.

32. Differentiate between direct lattice and reciprocal lattice. Explain the

significance of reciprocal lattice vector and represent Bragg’s diffraction law

in terms of reciprocal lattice vector.

33. With a neat diagram, explain the arc discharge method to synthesize single

wall carbon nanotubes.

34. Design a computer switching device using carbon nanotubes.

35. Write a note on challenges in fabricating NEMS.

36. What revolution will bring in as a result of the discovery of single electron

transistor?


37. Suppose you have synthesized a nanostructured sample in the form of a film.

What are the techniques that can be adopted to characterize it. Also give a brief

account of the uses of nanostructured films in science and technology.

38. Twenty first century is considered to be the nanotechnology era. Discuss this

statement in the wake of your knowledge and possible a scientist’s imagination.

39. Explain in detail the operating principle and possible applications of Resonant

Tunneling diode and Quantum Cascade lasers

64


Model Question Paper PY1651.5 –Computer Hardware and Networking (Elective Course)

Time 3 hours Total weightage : 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I.

1. The 8085 microprocessor use ------ V power supply.

a. +5V b. – 5V c. + 12V d. – 12 V

39. Which of the following holds the CPU,RAM and expansion cards

a. Hard disk b. Floppy disk c. Motherboard d. none of the previous

40. Actual execution of instructions in a computer takes place in

a. ALU b. Control unit c. Keyboard d. Storage unit

41. Information retrieval is faster from

a. Floppy disk b. Pen drive c. Hard disk d. CD-ROM

65

II. 5. Execution of two or more program by a single CPU is known as

a. multiprocessing b. multiprogramming c. time sharing d. none of the previous

6. Cache memory enhances

b. memory capacity b. memory access time

c. secondary storage capacity d. secondary storage access time.

7. CISC machines have

a. fewer instruction than RISC machines b. more RAM than RISC machines

c. medium clock speed d. variable size instructions

8. A Pentium processor comprises

a. more than I million transistors b. more than 3 million transistors c. only I million transistors d. 500000 transistors only

III. 40. DRAM

a. is used for cache memory b. is more expensive than SRAM c. is cheaper than SRAM d. is only used to boot up time

41. The communication line between the CPU , memory and peripherals is called a

a. bus b. line c. media d. none of the previous

42. LAN speeds are measured in

b. bps b. kbps c. mbps d. mips

43. Ethernet uses

a. bus topology b. ring topology c. mesh topology d. None of these

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IV. State whether the following statements are true or false. 44. Data are loaded from secondary to primary storage in a nondestructive read

process.

45. An SMPS is designed to deliver 4 discrete outputs and incorporate a switching

regulator

46. LAN is a group of computers connected by a shared medium, usually a cable

47. OSI model is a four layer model designed by ISO.

SECTION B [Answer any EIGHT questions. Each question ca rries a weightage of ONE.] 17. What is BIOS and what are its functional parts? 18. Compare the features of a Pentium 4 and an AMD Athlon processors. 19. Discuss about FAT and boot sector. 20. What is partitioning of disk drive? Discuss 21. What is a serial mouse and a bus mouse? 22. What are Trojan and worms ? 23. What is Bluetooth technology ? 24.. Differentiate between LAN and WAN 25. Define Topology. Specify the types of topologies 26. Define Protocol 27. Explain IP addressing method 28. Mention the duties of the transport layer SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29. Draw the functional block diagram of a Hard disk controller. 30. Write the diagnosis procedure and troubleshooting for the following keyboard error a. complete non – operation of the keyboard. b. non operation of some keys in the keyboard. c. keyboard interface problem. 31. Discuss the diagnosis and troubleshooting methods for the following problems in HDD a. system is not booting from the hard disk b. disk performance was slow c. system displays ‘ No fixed disk present ‘ error message on the monitor. 32. Draw the block diagrams of a. online UPS b. offline UPS 33. Write note on a. universal serial bus

67

b. IEEE Firewire 34. Change the following IP addresses from dotted-decimal notation to binary notation. a. 111 . 34 . 28 b. 129 . 14 . 6 . 8 c. 205 . 23. 67 . 9 35. Change the following IP addresses from binary to dotted-decimal notation a. 01111111 11110000 01100111 01111101 b. 10101111 11000000 11111000 00011101 c. 11011111 10110000 00011111 01011101 36. Find the class of the following IP address a. 128 . 11 . 3 . 31 b. 238 . 56 . 2 . 1 c. 114 . 13 . 4 . 0 SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37. Explain the components of motherboard in detail. 38. Explain the various hard disk sub assemblies. Discuss about the configuration of hard disk drive. 39. With a neat sketch explain OSI reference model. Explain the duties of different layers.

UNIVERSITY OF KERALA B.Sc Degree Programme in (Complementary) Physics

Model Question Paper PY1131.1 – Mechanics and Properties of matter (For Mathematics Main only)


I. 1. Moment of inertia of a circular disc of mass M and radius R about its diameter is

(a) MR2 (b) MR2/2 (c) MR2/3 (d) MR2/4

2. Shearing strain is related to

68

(a) Young’s modulus (b) Bulk modulus (c) Rigidity modulus (d) None of these

3. The limiting values of Poisson’s ratio are

(a) -1 and 0 (b) -1 and 0.5 (c) 1 and -0.5 (d) 1 and 0

4. The dimensions of surface tension are

(a) ML0T-2 (b) ML-1T-2 (c) ML-1T-1 (d) ML2T-2

II. 5. As temperature increases, the viscosity of a gas

(a) Increases (b) Decreases (c) Does not change

(d) First increases and then decreases

6. The main cause for the viscous drag in a liquid is

(a) Surface tension (b) Friction (c) Inertia (d) None of these

7. Which one of the following is not a SHM

(a) Oscillations of a loaded spring (b) Vibrations of atoms

(c) Motion of the minute hand of a clock (d) Vibrations of a tuning fork

8. Oscillatory motion occurs when the system is displaced from the position of

(a) Stable equilibrium (b) Unstable equilibrium

(c) Neutral equilibrium (d) None of these

III. 9. The rotation of the earth can be demonstrated using a ____________.

10. A swimmer jumping into water from a height makes loops in air making use of

___________ law.

11. The ratio of lateral strain to longitudinal strain is called __________.

12. Two pendulum of equal length l and mass m are coupled by a mass less spring

69

of spring constant k. The normal frequencies are ___________.


13. Gyroscopes are used in ships to find directions.

14. An egg standing on one end is an example of unstable equilibrium.

15. The angle of contact of mercury with glass is obtuse.

16. The viscosity of water increases with increase in temperature.


17. Explain the physical significance of moment of inertia.

18. Explain why there are two propellers in a helicopter.

19. With the help of a stress-strain diagram, explain elastic limit and yield point.

20. Why are girders I-shaped?

21. Water spreads on a clean glass plate but collects into drops on a greased glass

plate. Why?

22. Explain the variation of surface tension of a liquid with temperature.

23. Even though ‘lava’ is highly viscous it flows rapidly. Why?

24. Define coefficient of viscosity.

25. What are beats? How are they produced?

26. Write down the differential equation of a damped SHM.

27. Explain the variation of potential energy and kinetic energy with displacement of

a particle executing SHM.

28. Explain velocity resonance.

70


29. A fly wheel of mass 250 kg and 0.6 m radius makes 300 rpm. Assuming its mass

to be concentrated ay the rim, calculate the moment of inertia of the fly wheel.

30. A sphere of mass m and radius r rolls on a horizontal plane without slipping. What

fraction of its total energy is rotational?

31. Calculate the load that must be suspended from a steel wire of diameter 1 mm to

produce an elongation of 0.01% of its original length. Young’s modulus of steel =

200×109 N/m2.

32. Calculate the pressure inside an air bubble of radius 1 mm formed just below the

surface of water. Surface tension of water = 72×10-3 N/m. Atmospheric pressure

= 1.013×105 N/m2.

33. Two soap bubbles of radii 6 cm and 8 cm coalesce in vacuum under isothermal

conditions. Calculate the radius of the new bubble formed.

34. A metal plate of 0.05 m2 area rests on a layer of oil 2 mm thick. Calculate the

horizontal force required to move the plate with a velocity of 0.2 m/s. Coefficient

of viscosity of the oil= 1.56 Ns/m2.

35. The maximum velocity of a particle executing SHM is 1.5 m/s and period is 0.15

sec. Find the amplitude and maximum acceleration.

36. The intensity of a point source emitting sound at a distance 3 m from the source is

0.707 W/m2. What is the average power output of the source?

71


37. Describe with necessary theory the method of determining the rigidity

modulus of the material of a wire using torsion pendulum.

38. Derive an expression for the rate of flow of a liquid through a capillary tube.

Explain the corrections.

39. Arrive at the differential equation of a forced harmonic oscillator and give its

solution.


Model Question Paper PY1231.1 – Heat and Thermodynamics (For Mathematics Main only)


I. 1. Compared to ordinary light waves, the wavelength of thermal radiations is

(a) Larger (b) Smaller (c) Equal (d) None of these

2. Fery’s black body is

(a) Spherical (b) Cylindrical (c) Cone shaped (d) None of these

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3. The total energy radiated per second from unit area of a black body is

proportional to

(a) T (b) T2 (c) T3 (d) T4

4. Wien’s distribution law for thermal radiations is applicable for

(a) Longer waves (b) Shorter waves (c) Medium waves (d) All waves

II. 5. The efficiency of a Carnot engine working between temperatures T1 and T2

(T1>T2) is

(a) 1-(T2/T1) (b) 1-(T1/T2) (c) (T1/T2)-1 (d) (T2/T1)-1

6. The efficiency of a practical heat engine is

(a) Less than one (b) Greater than one (c) Equal to one (d) None of these

7. When pressure is increased, the boiling point of a liquid

(a) Increases (b) Decreases

(c) First increases and then decreases (d) Does not change

8. During an adiabatic process which of the following remains constant

(a) Pressure (b) Volume (c) Temperature (d) Entropy

III. 9. The absorptive power of a perfectly black body is equal to ____________.

10. The instrument used to measure solar constant is called ___________.

11. The process in which the pressure remains constant is called __________.

12. If P is the pressure and ? is the ratio of specific heats of an ideal gas, the

adiabatic elasticity is ___________.


73

13. An irreversible process is followed by an increase in entropy.

14. The efficiency of a diesel engine is greater than that of a petrol engine.

15. When work is done by an isolated system its internal energy decreases.

16. Thermal radiations are electromagnetic in nature.


17. Explain why heat conduction is a slow process.

18. State Wien’s displacement law.

19. The metal strip used in Angstrom pyrheliometer is made of platinum or

manganin. Why?

20. Write down any four properties of radiations from a uniform temperature

enclosure.

21. Show that adiabatic curve is steeper than isothermal curve.

22. Explain why a heavy fly wheel is used in heat engines.

23. Explain the effect of melting point of ice with pressure.

24. What are the advantages of diesel engine?

25. Draw the labeled indicator diagram for Otto cycle.

26. Explain why an adiabatic process is called an isentropic process.

27. How is entropy and disorder related?

28. Is it possible to get a negative temperature on Kelvin’s scale? Explain.


29. The temperature of a perfectly black body is 600 K and area of its radiating

74

surface is 2×10-3 m2. Find the energy radiated by the surface in 10 minutes. s

= 5.7×10-8 Wm-2K-4.

30. The temperature of an electric bulb changes from 1500 K to 2000 K due to a.c

voltage fluctuations. Calculate the percentage rise in electric power consumed.

31. A tyre has an air pressure of 4 atmospheres at a temperature of 300 K. If it

bursts suddenly, calculate the final temperature. ? = 1.4

32. Calculate the increase in temperature of water falling from a height of 300 m

assuming that the whole kinetic energy due to fall is converted into heat.

Specific heat capacity of water = 4200 J/Kg/K

33. Calculate the coefficient of performance of an ideal refrigerator working

between -150C and 350C.

34. The two ends of a copper rod of length 0.8 m and radius 5 mm are kept

between boiling water and ice at 00C. If 100 gm of ice melts in one hour,

calculate the thermal conductivity of copper. Latent heat of fusion of ice = 336

kJ/kg.

35. Calculate the change in entropy when 100 gm of water at 400C is converted

into steam at 1000C. Specific heat of water = 4200 J/kg/K, Latent heat of

steam = 2.26×106 J/kg.

36. A Carnot engine has the same efficiency (i) between 100K and 500K and

(ii) T K and 900K. Calculate the value of T.

SECTION D

75

[Answer any TWO questions. Each question carries a weightage of FOUR]

37. With necessary theory explain how thermal conductivity of a bad conductor is

determined by Lee’s disc method.

38. Define solar constant. Describe an experiment to determine the solar constant

using a pyrheliometer.

39. (a) What is an indicator diagram? Explain its significance.

(b) Derive an expression for the work done by an adiabatic process.


Model Question Paper PY1331.1 – Optics, Magnetism and Electricity (For Mathematics Main only)


I. 1. A device based on interference due to division of amplitude is

(a) Biprism (b) Newton’s rings (c) Double mirror (d) None of these

2. Formation of colours in thin films is due to

(a) Interference (b) Diffraction (c) Polarization (d) Dispersion

76

3. Which of the following is not correct?

(a) Interference maxima have equal thickness (b) Diffraction maxima have

equal thickness (c) Interference maxima have equal intensity

(d) Diffraction maxima have varying intensity

4. Which of the following is not applicable to laser?

(a) Monochromatic (b) Divergent (c) Intense (d) Coherent

II. 5. Pulse dispersion is maximum in

(a) Step index fibre (b) Graded index fibre (c) Single mode fibre

(d) None of these

6. Which one of the following is a paramagnetic substance?

(a) Antimony (b) Bismuth (c) Gold (d) Aluminium

7. In a pure inductive circuit, the phase difference between current and voltage is

(a) 00 (b) 450 (c) 900 (d) 1800

8. In a series LCR circuit if the current is wattless, the power factor will be

(a) Zero (b) One (c) Infinity (d) None of these

III. 9. Two waves of same amplitude ‘a’ each interfere each other. The intensity of

maxima are ____________.

10. Fringes of equal inclination are also known as ___________.

11. The bending of light around corners of opaque objects is called __________.

12. The expression for the Q factor of a series LCR circuit is ___________.


77

13. The refractive index of a material is independent of the wavelength of incident

light.

14. In Newton’s rings arrangement, the central band is normally dark.

15. An atomic system with a metastable state is required to produce laser.

16. The magnetic permeability of a ferromagnetic substance is less than one.


17. Explain why very thin films appear black in reflected light.

18. Explain why Newton’s rings are circular while fringes of air wedge are straight

and parallel.

19. Distinguish between prism spectra and grating spectra.

20. What are Haidinger’s fringes?

21. Explain absent spectra in double slit diffraction.

22. What is meant by permeability and susceptibility? How are they related?

23. Define time constant of an LR circuit.

24. Explain sharpness of resonance in series resonant circuit.

25. What is a choke coil? Mention its advantage over a resistor.

26. Distinguish between spontaneous emission and stimulated emission.

27. Write down any four applications of laser.

28. Explain why a series LCR circuit is called an acceptor circuit.


78

29. In a biprism experiment 100 fringes were observed with 600 nm light. How

many fringes will be observed if the wavelength is changed to 500 nm and the

set up remains unchanged?

30. Light of wavelength 593 nm falls normally on a thin wedge shaped film of

refractive index 1.4 forming fringes that are 1 mm apart. Find the angle of the

wedge.

31. In a Newton’s rings arrangement the diameter of the 4th and 12th dark rings are

4 mm and 7 mm respectively. Find the diameter of the 20th dark ring.

32. A lens of focal length 40 cm forms a Fraunhofer diffraction pattern of a slit of

0.2 mm width. Calculate the distance of the first dark band from the axis for

light of wavelength 589 nm.

33. A plane transmission grating has 6000 lines/cm over a length10 cm. Find the

resolving power of the grating and the smallest wavelength that can be

resolved in the 600 nm wavelength region.

34. A capacitor of capacity 0.1 µF is connected with an inductance of 1 mH.

Calculate the natural frequency of the circuit.

35. Find the value of the inductance that should be connected in series with a

capacitor of 5 µF, a resistance 100 O and an ac source of frequency 50 Hz so

that the power factor is unity.

36. A magnetic field of 0.5 T is applied to a paramagnetic gas whose atoms have

an intrinsic magnetic dipole moment of 1.2×10-23J/T. At what temperature

will the mean kinetic energy of translation of the gas atoms be equal to the

energy required to reverse a dipole end for end in this magnetic field.

SECTION D

79


37. Describe with necessary theory, an experiment to determine the wavelength

monochromatic light using Newton’s rings arrangement.

38. Describe the phenomenon of Fresnel diffraction at a straight edge. Give an

example for the same.

39. Derive an expression for the current in a series LCR circuit when an

alternating voltage is applied on it. Obtain the condition for resonance.


Model Question Paper PY1431.1– Modern Physics and Electronics (For Mathematics Main only)


I. 1. Which of the following is not a radioactive radiation?

(a) a rays (b) ß rays (c) ? rays (d) X rays

2. Which of the following radioactive series has Pu239 as the parent atom?

(a) Uranium series (b) Thorium series

(c) Actinium series (d) Neptunium series

80

3. Nuclear density in S.I units is of the order of

(a) 1017 (b) 1010 (c) 10-10 (d) 10-2

4. The energy per fission of U235 is about

(a) 1 MeV (b) 50 MeV (c) 200 MeV (d) None of these

II 5. The transistor configuration which has current gain less than one is

(a) Common base (b) Common emitter (c) Common collector

(d) None of these

6. Lightly doped region of the transistor is

(a) Emitter (b) Base (c) Collector (d) Emitter and collector

7. The relation between transistor a and transistor ß is

(a) ß= a/(1-a ) (b) a= ß/(1-ß) (c) ß= a/(1+a) (d) a= 2ß/(1+ß)

8. The commonly used biasing circuit in amplifiers is

(a) Fixed bias (b) Collector to base bias (c) Voltage divider bias

(d) None of these

III. 9. The magnitude of the spin quantum number of an electron is ___________.

10. A radioactive radiation which is electromagnetic in nature is ____________.

11. The binary equivalent of the decimal number 16 is ___________.

12. The logic gate which has only one input is __________.


13. a rays are electromagnetic in nature.

14. The stability of a nucleus depends on the number of protons and neutrons in it.

15. The common collector configuration of a transistor can be used as impedance

81

matching circuit.

16. Negative feedback is used in transistor oscillators.


17. What are the features of vector atom model?

18. Explain various coupling schemes.

19. Show that the energy levels of a particle in a box is quantized.

20. What are the limitations of Bohr atom model?


22. Define mass defect of a nucleus.

23. Explain the significance of the wave function.

24. State and explain DeMorgan’s theorems.

25. Explain the terms eigen value and eigen function.

26. Explain the phase reversal of a transistor amplifier

27. What is Berkhausen criterion for oscillations?

28. Which of the three transistor configurations is preferred? Why?


29. A radioactive substance has a half life of 30 days. Calculate the time taken to

decay 25% of the given sample of the substance.

30. The binding energy per nucleon for C12 is 7.68 MeV and that of C13 is 7.47

MeV. Calculate the energy required to remove one neutron from C13.

82

31. The wavelength of a line in hydrogen spectrum is 500 nm. Find out the related

energy change of the in electron volt.

32. Calculate the energy difference between the ground state and the first excited

state for an electron in a one dimensional rigid box of length 1 A0.

33. What is the lowest energy that a neutron of mass 1.67×10-27 kg can have if it is

confined to move along the edge of an impenetrable box of length 10-14 m.

34. In a canter tapped full wave rectifier maximum voltage across half of the

secondary winding is 50 V. If the load resistance is 200O, calculate the dc

output voltage and the peak inverse voltage.

35. A 10 Volt Zener diode along with a series resistor is connected across a 40 V

supply. Calculate the minimum resistance required if the maximum Zener

current is 50 mA.

36. In a transistor amplifier, when signal changes by 0.02 V, the base current

changes by 10 µA and the collector current changes by 18 mA. If the collector

load RC = 5 kO and RL = 10 kO, find the current gain and voltage gain.


37. Derive the general equation of growth and decay of radioactive series. Explain

secular and transient radioactive equilibrium.

38. Obtain Schrödinger wave equation for a particle in a one dimensional rigid

box. Solve it to obtain eigen functions and show that eigen values are discrete.

39. Explain the rectifying action of a p-n junction diode. With the help of a neat

circuit diagram, explain the working of a full wave rectifier using two diodes.

83


Model Question Paper PY1131.2 – Rotational Dynamics and Properties of matter (For Chemistry & Polymer Chemistry Main)


I. 1. Moment of inertia of a solid sphere of mass M and radius R about its diameter is

(a) 1/3MR2 (b) MR2/2 (c) 2MR2/3 (d) 2MR2/5

2. Within the elastic limit, the ratio of the lateral strain to linear strain is called

(a) Young’s modulus (b) Bulk modulus (c) Rigidity modulus

(d) Poisson’s ratio

3. The limiting values of Poisson’s ratio are

(a) -1 and 0 (b) -1 and 0.5 (c) 1 and -0.5 (d) 1 and 0

84

4. The S.I unit of coefficient of viscosity is

(a) Ns/m2 (b) Ns2/m (c) Ns/m (d) Ns2/m2




6. The main cause for the viscous drag in a liquid is

(a) Surface tension (b) Friction (c) Inertia (d) None of these

7. Which one of the following is not a SHM?






III. 9. The main cause for the viscous drag in a liquid is _________


___________ law.





13. Gyroscopes are used in ships to find directions.

85





17. State the theorem of parallel axes.

18. Explain why the mass of fly wheel is concentrated at its rim.

19. Explain why steel is more elastic than rubber.


21. A needle can float in clean water but sinks in soap solution. Why?

22. How does the surface tension of a liquid vary with temperature?

23. What are the conditions under which Poiseuille’s formula is valid?

24. Define coefficient of viscosity.





28. What is Q-factor of a harmonic oscillator?


29. A circular disc of mass 0.5kg and radius 0.1 m is making 120 rpm about an axis

passing through its centre and perpendicular to its plane. Calculate its kinetic

energy.

86

30. Calculate the ratio of K.E of translation to the total K.E of a sphere rolling without

slipping on a horizontal surface.



200×109 N/m2.



= 1.013×105 N/m2.













87

38. Derive an expression for the rate of flow of a liquid through a capillary

tube. Explain the corrections.

39. Arrive at the differential equation of a forced harmonic oscillator and

give its solution.


Model Question Paper PY1231.2 – Heat and Thermodynamics (For Chemistry & Polymer Chemistry Main)


I. 1. Which of the following is not applicable to thermal radiations

(a) Electromagnetic waves (b) Show interference and diffraction

(c) Do not obey inverse square law (d) Obey laws of refraction

2. The amount of energy radiated per second per unit area of a body is called its

(a) Emissivity (b) Emissive power (c) Absorptive power (d) Reflecting power

3. Pyrheliometer is an instrument used for measuring

88

(a) Solar constant (b) Temperature of the Sun (c) Emissivity

(d) Emissive power



II. 5. Which of the following is not a thermodynamic coordinate

(a) Pressure (b) Entropy (c) Viscosity (d) Temperature






8. The area under the indicator diagram of a thermodynamic system represents

(a) Enthalpy (b) Work done (c) Pressure (d) Entropy



11. The process in which the volume remains constant is called __________.






89







manganin. Why?

20. Write down any four properties of radiations from a uniform temperature

enclosure.



23. Explain the effect of melting point of ice with pressure.







29. The temperature of a perfectly black body is 600 K and area of its radiating

surface is 2×10-3 m2. Find the energy radiated by the surface in 10 minutes. s

= 5.7×10-8 Wm-2K-4.

90













kJ/kg.



steam = 2.26×106 J/kg.






91






Model Question Paper PY1331.2 – Optics, Magnetism and Electricity (For Chemistry & Polymer Chemistry Main)


1) 1. The interference phenomenon can take place (a) in all waves (b) in transverse waves only (c) in longitudinal waves only (d) in standing waves only


(a) Interference (b) Diffraction (c) Polarization (d) Dispersion



92







(d) None of these

6. Which one of the following is a paramagnetic substance?

(a) Antimony (b) Bismuth (c) Gold (d) Aluminium


(a) 00 (b) 450 (c) 900 (d) 1800




maxima are ____________.






light.

93







and parallel.




22. What is meant by permeability and susceptibility? How are they related?




26. Distinguish between spontaneous emission and stimulated emission.




29. In a biprism experiment 100 fringes were observed with 600 nm light. How

many fringes will be observed if the wavelength is changed to 500 nm and the

set up remains unchanged?

94

30. Light of wavelength 593 nm falls normally on a thin wedge shaped film of

refractive index 1.4 forming fringes that are 1 mm apart. Find the angle of the

wedge.

31. In a Newton’s rings arrangement the diameter of the 4th and 12th dark rings are

4 mm and 7 mm respectively. Find the diameter of the 20th dark ring.

32. A lens of focal length 40 cm forms a Fraunhofer diffraction pattern of a slit of

0.2 mm width. Calculate the distance of the first dark band from the axis for

light of wavelength 589 nm.

33. A plane transmission grating has 6000 lines/cm over a length10 cm. Find the

resolving power of the grating and the smallest wavelength that can be

resolved in the 600 nm wavelength region.

34. A capacitor of capacity 0.1 µF is connected with an inductance of 1 mH.

Calculate the natural frequency of the circuit.

35. Find the value of the inductance that should be connected in series with a

capacitor of 5 µF, a resistance 100 O and an ac source of frequency 50 Hz so

that the power factor is unity.

36. A magnetic field of 0.5 T is applied to a paramagnetic gas whose atoms have

an intrinsic magnetic dipole moment of 1.2×10-23J/T. At what temperature

will the mean kinetic energy of translation of the gas atoms be equal to the

energy required to reverse a dipole end for end in this magnetic field.


37. Describe with necessary theory, an experiment to determine the

wavelength monochromatic light using Newton’s rings arrangement.

95

38. Describe the phenomenon of Fresnel diffraction at a straight edge. Give an

example for the same.

39. Derive an expression for the current in a series LCR circuit when an

alternating voltage is applied on it. Obtain the condition for resonance.


Model Question Paper PY1431.2 – Modern Physics and Electronics (For Chemistry & Polymer Chemistry Main)


I. 1. Which of the following is not a radioactive radiation?

(a) a rays (b) ß rays (c) ? rays (d) X rays




3. Nuclear density in S.I units is of the order of

(a) 1017 (b) 1010 (c) 10-10 (d) 10-2

96

4. The energy per fission of U235 is about

(a) 1 MeV (b) 50 MeV (c) 200 MeV (d) None of these



(d) None of these







(d) None of these

III. 9. The magnitude of the spin quantum number of an electron is ___________.





13. a rays are electromagnetic in nature.


15. The common collector configuration of a transistor can be used as impedance

matching circuit.


97


17. What are the features of vector atom model?


19. Show that the energy levels of a particle in a box is quantized.




23. Explain the significance of the wave function.


25. Explain the terms eigen value and eigen function.





29. A radioactive substance has a half life of 30 days. Calculate the time

taken to decay 25% of the given sample of the substance.

30. The binding energy per nucleon for C12 is 7.68 MeV and that of C13 is

7.47 MeV. Calculate the energy required to remove one neutron from

C13.

31. The wavelength of a line in hydrogen spectrum is 500 nm. Find out the

related energy change of the in electron volt.

98

32. Calculate the energy difference between the ground state and the first

excited state for an electron in a one dimensional rigid box of length 1

A0.

33. What is the lowest energy that a neutron of mass 1.67×10-27 kg can

have if it is confined to move along the edge of an impenetrable box of

length 10-14 m.

34. In a canter tapped full wave rectifier maximum voltage across half of

the secondary winding is 50 V. If the load resistance is 200O, calculate

the dc output voltage and the peak inverse voltage.

35. A 10 Volt Zener diode along with a series resistor is connected across

a 40 V supply. Calculate the minimum resistance required if the

maximum Zener current is 50 mA.

36. In a transistor amplifier, when signal changes by 0.02 V, the base

current changes by 10 µA and the collector current changes by 18 mA.

If the collector load RC = 5 kO and RL = 10 kO, find the current gain

and voltage gain.


37. Derive the general equation of growth and decay of radioactive series.

Explain secular and transient radioactive equilibrium.

38. Obtain Schrödinger wave equation for a particle in a one dimensional

rigid box. Solve it to obtain eigen functions and show that eigen values

are discrete.

99

39. Explain the rectifying action of a p-n junction diode. With the help of a

neat circuit diagram, explain the working of a full wave rectifier using

two diodes.


Model Question Paper PY1131.3 – Mechanics and Properties of matter (For Statistics Main)


I (1) Moment of Inertia of a sphere of mass m and radius R about an axis through the diameter is A.2/5 MR2 B. 5/2 MR2 C. 7/5 MR2 D. 5/7 MR2 (2) If l is the distance between centre of suspension ad C.G of a compound pendulum, then the length of equivalent simple pendulum is A.v(k2+l2) B. (k2/l) +l C. l +(l2/k) D.v((k2+l2)/l2) (3) In a simple harmonic oscillator the P.E and K.E Becomes equal at the position. A. x=a B. x=a/2 C. x=a/v2 D. x==0 (4) The total K.E of a simple harmonic oscillator is proportional to A. amplitude B. square of amplitude C. Velocity D.

100

Square root of displacement. II(5) the depression in the middle of girder for a given load depends on A. Length and breadth. B. breadth and depth C. depth D. length breadth and depth (6) The excess of pressure inside a cylindrical drop of liquid with surface tension s and radius r is A.2s/r B. s/r C.4s/r D.s/2r (7) Hot syrup flows faster because A. surface tension decreases B. Viscosity decreases C. surface tension increases D. Viscosity increases (8) The dimensions of viscosity is A. M-1 L1 T0 B. M0 L-1 T-1. C.M2 L-1 T-2 D. M L2 T-1. III Fill in the blanks (9) The mass of the flywheel is concentrated at it’s ........................ (10)In gases the modulus of elasticity involved is............................. (11)External bending moment required to produce a unit radius of curvature is called................................. (12) The instrument used to compare the viscosity of a liquid at two different temperatures is.......................... IV.State whether the following statements are true or false. (13) When a ring and disc of same mass rotates about their diameter Ring has greater moment of inertia. (14) In a harmonic oscillator K.E. is maximum at its mean position (15) Compressibility is the reciprocal of Bulk modulus. (16) Sound waves travel faster in humid air. SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE] (17). Write two factors that affect the M.I of a body. (18) What is radius of gyration? What is its value for a solid cylinder about an axis passing through one end and perpendicular to its axis? (19).Obtain an expression for the K.E.of a rotating body. (20). Draw a graph showing the variation of K.E.of a body executing S.H.M. (21) .Define centre of oscillation and centre of suspension of a compound pendulum. (22). What do you understand by the energy density of a plane progressive wave. (23) Show that a hollow shaft of the same length, mass and material is comparatively stronger than a solid one.

101

(24). What is torsional rigidity of a wire? On what factors do the torsional rigidity depends. (26). Derive an expression for the bending moment. (27). A drop of mercury is formed on a glass plate. Show in a figure the angle of contact and surface tension. (28). What are the conditions under which Poiseuille’s formula is derived. SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO] (29).A solid sphere of mass o.5kg. and 1m diameter rolls without slipping with a constant velocity 5m/s along a smooth horizontal plane. Calculate the total energy (30).A thin uniform of length 2m and mass 4kg is bend in the form of a square oscillating about the centre of mass and about a vertical plane. Calculate its M.I. (31).A cantile ver of length 60cm is depressed by 20mm at loaded end. What is the depression at a distance 40cm from the fixed end. (32).Calculate the work done in twisting a steel wire of radius 103m and length 0.25m through an angle of 45 .The modulus of rigidity of the material is 8 Nm. (33).The mass of a wire of length 5m is 2 kg. What should be the tension in the wire so that the speed of transverse wave on the wire is340m/s. (34).Calculate the pressure inside an air bubble of diameter 0.2mm. situated just below the surface of water. (35).The velocity of sound in hydrogen 1320m/s.What will be the velocity of sound in a mixture of 2 parts by volume of hydrogen one part by volume of oxygen. (36).Water flows through a horizontal tube of length 0.2m and internal radius 8*10 m under constant pressure head of the liquid 0.2m high. In 12 minutes 8.64 of liquid is coming out of the tube. Calculate the coefficient of viscosity. Density of liquid is 1000kg/m3 SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] (37).State and prove parallel axis theorem. Derive an expression for the M,I. of a uniform bar of rectangular cross section about an axis passing through its corner and perpendicular to its length (38). Derive an expression for the longitudinal waves along a solid rod. (39). Describe Jaegers experiment to determine surface tension of a liquid.

102


Model Question Paper PY1231.3 – Thermal Physics and Statistical Mechanics (For Statistics Main)


I. 1. Which of the following is not applicable to thermal radiations

(a) Electromagnetic waves (b) Show interference and diffraction

(c) Do not obey inverse square law (d) Obey laws of refraction

2. If a gas is allowed to expand adiabatically, the temperature of the gas will

(a) Rise (b) Fall (c) Remain unchanged (d) Depends on the nature of gas

3. The change in entropy during a Carnot’s cycle is

103

(a) Maximum (b) Minimum (c) Exactly one (d) Zero





6. To increase the efficiency of a Carnot’s engine most effectively, the temperature

of the

(a) Sink must be lowered (b) Sink must be increased (c) Source must be

increased (d) Source must be lowered













104





17. Lees disc method is not suitable for good conductors. Why?

18. State Wiedemann-Franz law.

19. What are the limitations of Wein’s explanation of black body spectrum?

20. Calculate the work done when a gas expands adiabatically.


22. What factors reduce the efficiency of a heat engine from its ideal value?

23. Explain the term ensemble.

24. What are Bosons and Fermions?

25. Show that there is always an increase in entropy in an irreversible cycle.



28. Explain Maxwell-Boltzmann distribution law.


29. Calculate the quantity of heat conducted per minute through a glass window

pane 0.5m2 and 5mm thick, if the inside temperature is 200C and the outside

temperature is 400C. Thermal conductivity of glass = 10.05 W/m/K.

30. If the wavelength of maximum energy in the solar spectrum is 475nm,

105

calculate the effective temperature of the Sun. Wein’s constant = 2.898×10-3mK



32. The efficiency of a Carnot cycle is 20%. On reducing the temperature of the

sink by 650C, the efficiency increases to 40%. Find the temperatures of the

source and sink.






kJ/kg.



steam = 2.26×106 J/kg.






38. Explain Carnot’s cycle. Derive an expression for the efficiency of a Carnot’s

106

engine.




Model Question Paper PY 1331.3-Physical and Modern Optics and Electricity

(For Statistics Main only) Time: 3 Hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I

2) Two waves having intensities in the ratio 9:1 produce interference .The ratio of the maximum to minimum intensity is (a) 10:8 (b) 9:1 (c) 4:1 (d) 2:1

3) The interference phenomenon can take place (a) in all waves (b) in transverse waves only (c) in longitudinal waves only (d) in standing waves only

4) A slit of width e is illuminated by light of wavelength ?. The first minimum will be obtained at an angle of diffraction 60 0 provided (a) e= ?/v3 (b) e = 2?/v3 (c) e = v3 ? (d) e = v3 ? /2

5) Laser light is (a) Highly monochromatic (b) Highly coherent (c) Highly directional

(d) All the three II

6) In a grating spectra which spectral line in the fourth order will overlap with the third order of 5461 ?

107

(a) 4039 ? (b) 4069 ? (c) 4096 ? (d) 4079 ? 7) The basic ingredient of optical glass fibres is

(a) Calcium carbonate (b) Silica (c) Calcium sulphate (d) Germanium

8) Susceptibility is positive for (a) Paramagnetic substances (b) Ferro magnetic substances (c) Dia

magnetic substances (d) non magnetic substances 9) The peak value of an alternating current is 5 A and its frequency is 60 Hz. Its

r.m.s value is (a) 3.536 A (b) 4.256 A (c) 3.332 A (d) 3.86 A

III 10) Soap bubbles viewed in white light show colours. The phenomenon

responsible for it is__________. 11) The phase difference corresponding to a path difference of ? is___________. 12) The grating element of a diffraction grating have 5000 lines/cm is ________. 13) The opposition offered by an inductance to the flow of alternating current

through it is ______________. 1V State whether the following statements are true or false

13)The width and central maximum of the Fraunhofer diffraction will decrease when the

slit is made narrower. 14) Inside a magnet, the magnetic field lines move from the north pole to the south pole.

15) In transmitted light, if µ is the refractive index of the thin film and “t” its thickness, then the condition for bright fringes to occur is 2 µt cos r = n?.

16) The unit is is second.


17) Explain the colour of thin films. 18) What are the fringes of equal thickness? Give examples. 19) Explain the difference between diffraction and interference. 20) Define resolving power of a grating. 21) Distinguish between Fresnel diffraction and Fraunhofer diffraction. 22) Using a diagram explain the distribution of light in the diffraction pattern due to a

straight edge. 23) What is laser? Give an example of three level laser. 24) Explain the term population inversion. 25) Explain the electron theory of ferromagnetism. 26) Define susceptibility and permeability. 27) What is power factor? Give its significance. 28) What is a choke coil? What is its advantage over a resistor?

108

SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29) A parallel beam of sodium light (?=5890 ? ) strikes a thin film of oil floating on

water. When viewed at an angle of 300 from the normal, eighth dark band is seen. Determine the thickness of the film. (Refractive index of oil is 1.5)

30) In a Newton’s ring experiment, the diameter of the fourth dark ring is 0.34 cm using a light of wavelength 589.3nm.Calculate the radius of curvature of the convex lens.

31) Calculate the missing orders in a double slit diffraction pattern, given slit separation is 0.4 mm and the slit width is 0.2 mm.

32) What is the longest wavelength of light for which a spectrum can be obtained using a grating of 6000 lines/cm, under normal incidence?

33) A laser beam has a wavelength 800 nm and aperture 5 x 10 -3 m. The laser beam is sent to the moon. The distance of the moon is 4 x 10 5 km from the earth. Calculate the angular spread of the beam and the areal spread when it reaches the moon.

34) What is the instantaneous voltage of an ac supply of 220 volt and 50 Hz? 35) Find the inductive reactance and impedance of a circuit having an inductance 1/p henry and a resistance 50 ohm in series ,when an alternating e.m.f. of frequency 50 Hz is applied. 36) A 15 µF capacitor is connected to a 220 volt, 50 Hz source .Find the capacitive reactance and the current (r.m.s and peak) in the circuit. If the frequency is doubled what will happen to the capacitive reactance and the current? SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37) Describe an experiment to determine the wavelength of light by Newton’s rings method. 38) With a neat sketch explain the working of a ruby laser. 39) Derive an expression for the current in a series LCR circuit when an alternating current is impressed on it. Obtain the condition for resonance.

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Model Question Paper PY 1431.3- Modern Physics and Electronics

(For Statistics Main only) Time: 3 Hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I Choose the correct answer

1. The amount of original radioactive atom left behind after five half lives is (a) 3% (b) 5% (c) 10% (d) 20%

2. Radioactive substances do not emit (a) electrons (b) protons (c) e.m radiations (d) Helium nucleus

3. When the conductivity of a semiconductor is only due the breaking of the co valent bonds, the semi conductor is called (a) donor (b) accepter (c) intrinsic (d) extrinsic

4. The order of magnitude of the barrier potential in a pn junction diode (b) 0.01 V (b) 0.05 V (c) 0.1 V (d) 1.0 V

II 5. The resistance of a forward biased pn junction is

(a) zero (b) a few ohms (c) a few kilo ohms (d) infinite 6. In Boolean algebra which of the following is not equal to zero

(b) (b) (c) (d) 7. A binary number 11001101 means

(b) 205 (b) 305 (c) 405 (d) 505

110

8. In the case of wave function , the probability current density is (b) v/ r2 (b) v/r (c) v/ r3 (d) v

III 9. One curie = _______________________ decays / sec 10. The logic gate shown below is a ___________gate.

11. In the equation of the system 12. The spin angular momentum of an electron is always ______________.

1V State whether the following statements are true or false

13. Gamma rays are high energy neutrons 14) The resistance of a pure semiconductor at zero Kelvin is infinite.

15) Emitter – base junction of a transistor is reverse biased. 16) In quantum mechanics, wave function is a measure of probability.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.] 17) State the postulates of Bohr atom model. 18) Show that the binding energy varies with mass numbers of different nuclei. 19) Show the relation between decay constant and half life. 20) State Pauli’s exclusion principle. 21) Explain probability density. 22) State and explain Planck’s hypothesis. 23 Draw the I-V characteristics of a diode in (a) forward bias (b) reverse bias. 24) What are the special features of zener diode? 25) Distinguish between dc and ac load lines. 26) Draw the circuit diagram of a single stage common emitter amplifier. 27) What is binary number system? How does it differ from decimal number system? 28 What is Boolean algebra? Discuss the fundamental laws of Boolean algebra. SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29) The binding energy per nucleon for C12 is 7.68 MeV and that of C13 is 7.47 MeV.

Calculate the energy required to remove one neutron from C13. 30) Calculate the radio active decay constant for an element whose half life is 20

years. 31) Find the least energy of an electron moving in one dimension in an infinitely high

potential box of width 1 A0. (me = 9.11 x 10-31 kg, h = 6.63 x 10-34J.S) 32) A transistor is connected in the CE configuration. The collector supply voltage is

10 V and the voltage drop across the 500 O connected in the collector circuit is

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0.6 V. If a = 0.96, find (a) collector emitter voltage (b) base current, and (c) the emitter current.

33) The activity of a radioactive substance decreases to 1/64 of the original value in 21 years. Calculate the half life of the substance.

34) In a transistor circuit, the collector load is 4kO and the zero signal collector current is 1 mA. Determine the Q point if (a) Vcc = 10 V (b) Rc = 5 kO

35) A 9 V voltage regulated supply is required to run a car stereo system from 12 V battery. A zener diode with Vz = 9 V and Pmax = 0.25 W is used as a voltage regulator. Find the value of the series resistor.

36) Convert 359.310 to octal. SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37) State and explain the quantum numbers associated with the vector atom model. 38) Derive Schrödinger time independent equation. Give the physical interpretation

of the wave function ? . 39) Explain the terms ‘rectifier efficiency’ and ‘ripple factor’. Draw the circuit

diagram of a full wave bridge rectifier and explain its working


Model Question Paper PY1131.4 – Mechanics and Properties of matter (For Geology Main)


I. 1. Rotational motion can be produced by

(a) a force (b) a couple (c) two forces acting along a line

(d) none of these

2. A sphere rolls on a smooth surface. It has a

(a) Translational KE (b) Rotational KE (c) Both rotational and

translational KE (d) None of the above

112

3. Young’s modulus has the dimensions of

(a) stress (b) strain (c) force (d) bending moment

4. For a system to be stable, the potential energy should be

(a) maximum (b) minimum (c) infinity (d) none of these




6. In a wide river the velocity of water at the middle

(a) Decreases with depth (b) Increases with depth (c) same everywhere

(d) Zero

7. Which one of the following is not a SHM?






III. 9. The main cause for the viscous drag in a liquid is _________


___________ law.



113



13. In a harmonic oscillator K.E. is maximum at its mean position





17. Two spheres, one slides and the other rolls down an inclined plane. Which one

will reach the bottom first?

18. Explain why the mass of fly wheel is concentrated at its rim.

19. A metal wire is stretched between two wires and heated. What will happen to its

tension?


21. Explain why small drops of liquid assume spherical shape.

22. It is easier to blow small bubbles instead of large ones from soap solution. Why?

23. What are the conditions under which Poiseuille’s formula is valid?

24. What is the effect of temperature on viscosity of fluids?





114

28. What is Q-factor of a harmonic oscillator?


29. A circular disc of mass 0.5kg and radius 0.1 m is making 10 rps about an axis.

Find the work that must be done to increase the rate of revolution to 20 rps.

30. Calculate the ratio of K.E of translation to the total K.E of a sphere rolling without

slipping on a horizontal surface.



200×109 N/m2.



= 1.013×105 N/m2.










115




38. Derive an expression for the rate of flow of a liquid through a capillary tube.

Explain the corrections.

39. Arrive at the differential equation of a forced harmonic oscillator and give its

solution.


Model Question Paper PY1231.4 – Thermal Physics and Physics of the Earth (For Geology Main)


I. 1. The vaporization of a liquid at its boiling point is an example of

(a) Isothermal process (b) Adiabatic process

(c) Isochoric process (d) Conduction

2. The amount of energy radiated per second per unit area of a body is called its

(a) Emissivity (b) Emissive power (c) Absorptive power (d) Reflecting power

3. Pyrheliometer is an instrument used for measuring

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(a) Solar constant (b) Temperature of the Sun (c) Emissivity

(d) Emissive power

4. The sun heats the earth because of

(a) Radiation (b) Conduction (c) Convection (d) Scattering


















117




17. Explain why a body at 1000K is red hot while at 2000K is white hot.



manganin. Why?

20. Freezer chest in a refrigerator is fitted at the top. Why?

21. Why does the temperature of a gas decrease, when it is expanded

adiabatically?

22. Explain how a heat engine is different from a refrigerator.

23. Explain why the efficiency of a reversible engine is maximum.

24. Which are the different modes of heat transfer between sea and atmosphere?

25. Explain the mode of occurrence of ground water with respect to geological

area.

26. Define seismology.

27. Which factors are affecting the gravity of earth?

28. What are the sources of earth’s heat?


29. If the air temperature remains constant at -100C, find the time required for the

thickness of ice on a pond to increase from 2cm to 5cm. Assume water to be at

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00C. Density of ice = 0.92×103 kg/m3. Thermal conductivity of ice = 2.2

W/m/K. Latent heat of fusion of ice = 336×103 J/kg.





32. A Carnot engine is operated between two reservoirs at temperatures 500K and

400K. If the engine receives 5000J of heat from the source in each cycle,

calculate the amount of heat rejected to the sink in each cycle and the

efficiency of the engine.






kJ/kg.

35. A quantity of dry air at 270C is compressed suddenly to (1/3) of its volume.

Calculate the change in temperature. ? = 1.4



SECTION D

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38. Define gravitational field and potential. Derive expressions for the

gravitational field and potential due to a solid sphere at a point outside the

sphere and on the sphere.

39. Describe the construction and working of a diesel engine. What are the

differences between a petrol engine and a diesel engine.


Model Question Paper PY 1331.4-Optics and Electrodynamics

(For Geology Main Students) Time: 3 Hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I .1. Two waves having intensities in the ratio 9:1 produce interference .The ratio of the maximum to minimum intensity is

(a) 10:8 (b) 9:1 (c) 4:1 (d) 2:1 2.The interference phenomenon can take place

(a) in all waves (b) in transverse waves only (c) in longitudinal waves only (d) in standing waves only

3. A slit of width e is illuminated by light of wavelength ?. The first minimum will be obtained at an angle of diffraction 60 0 provided

(a) e= ?/v3 (b)e= 2?/v3 (c) e=v3 ? (d)e=v3 ? /2 4.Which of the following phenomena cannot take place in sound waves?

(c) Reflection (b) Interference (c) Diffraction (d) Polarization II

5. In a grating spectra which spectral line in the fourth order will overlap with the third order of 5461 ?

(a) 4039 ? (b) 4069 ? (c) 4096 ? (d) 4079 ? 6.In the propagation of light waves ,the angle between the direction of propagation and the plane of polarization is

(c) 00 (b) 450 (c) 900 (d)180 0

120

7. The Brewster’s law in polarization of light is (c) n Sin ip=1 (b) n Cos ip=1 (c) n tan ip=1 (d) n Cot ip=1

8. The horizontal component of the earth’s magnetic field is at a place is v3 times the vertical component .The value of the dip angle is

(c) 450 (b) 300 (c) 600 (d) 900 III

9. Soap bubbles viewed in white light show colours. The phenomenon responsible for it is__________. 10. The phase difference corresponding to a path difference of ? is___________. 11. The magnetic axis is inclined to the geographic axis at ________degrees. 12. The opposition offered by an inductance to the flow of alternating current through it is ______________.


13. The width and central maximum of the Fraunhofer diffraction will decrease when the slit is made narrower. 14) Inside a magnet, the magnetic field lines move from the North Pole to the South Pole. 15) To distinguish between an elliptically polarized light and a partially polarized light we make use of a quarter wave plate. 16) The earth’s magnetic field always has a horizontal component except at the Equator.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.] 17) Explain the colour of thin films. 18) What are the fringes of equal thickness? Give examples. 19) Explain the difference between diffraction and interference. 20) Define resolving power of a grating. 21) Distinguish between Fresnel diffraction and Fraunhofer diffraction. 22) State Brewster’s Law. 23) What is a half wave plate? Why is it called so? 24) Distinguish between dextro and laevo rotatory substances. 25) Explain the electron theory of ferromagnetism. 26) What are the magnetic elements of the earth? Explain. 27) What is power factor? Give its significance. 28) What is a choke coil? What is its advantage over a resistor? SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29) A parallel beam of sodium light (?=5890 ? ) strikes a thin film of oil floating on

water. When viewed at an angle of 300 from the normal, eighth dark band is seen. Determine the thickness of the film. (Refractive index of oil is 1.5)

30) In a Newton’s ring experiment, the diameter of the fourth dark ring is 0.34 cm using a light of wavelength 589.3nm.Calculate the radius of curvature of the convex lens.

31) Calculate the missing order in a double slit diffraction pattern, given slit separation is 0.4 mm and the slit width is 0.2 mm.

121

32) What is the longest wavelength of light for which a spectrum can be obtained using a grating of 6000 lines/cm, under normal incidence?

33) Find the thickness of (a) quarter wave plate (b) half wave plate when light of wavelength 589 nm is used.(µ O =1.55, µ E=1.54)

34) What is the instantaneous voltage of an ac supply of 220 volt and 50 Hz.? 35) Find the inductive reactance and impedance of a circuit having an inductance 1/p Henry and a resistance 50 ohm in series ,when an alternating e.m.f. of frequency 50 Hz is applied.

36) A 15 µF capacitor is connected to a 220 volt, 50 Hz source .Find the capacitive reactance and the current(r.m.s and peak) in the circuit. If the frequency is doubled what will happen to the capacitive reactance and the current? SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37) Describe an experiment to determine the wavelength of light by Newton’s rings method. 38) What is double refraction? Explain the working of a Nicol Prism and how is it used as a polarizer and an analyser? 39) Derive an expression for the current in a series LCR circuit when an alternating current is impressed on it. Obtain the condition for resonance


B.Sc Degree Programme in (Complementary) Physics Model Question Paper

PY 1431.4- Modern Physics, Electronics and Crystallography (For Geology Main only)

Time: 3 Hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I 1.The amount of original radioactive atom left behind after five half lives is

(a) 3% (b) 5% (c) 10% (d) 20% 14. Radioactive substances do not emit

(a) electrons (b) protons (c) e.m radiations (d)Helium nucleus 15. When the conductivity of a semiconductor is only due the breaking of the co valent

bonds, the semi conductor is called (a) donor (b) accepter (c) intrinsic (d) extrinsic

16. The order of magnitude of the barrier potential in a pn junction diode (d) 0.01 V (b) 0.05 V (c) 0.1 V (d) 1.0 V

II 17. The resistance of a forward biased pn junction is

(a) zero (b) a few ohms (c) a few kilo ohms (d) infinite 18. In Boolean algebra which of the following is not equal to zero

(d) (b) (c) (d) 19. A binary number 11001101 means

(d) 205 (b) 305 (c) 405 (d) 505 20. The total number of crystallographic symmetry elements of a cubical crystal is

122

(d) 23 (b) 24 (c) 22 (d) 21 III

21. One curie = _______________________ decays / sec 22. The logic gate shown below is a ___________gate.

23. The inter planar distance for a cubical structure in (h k l) plane is

24. If the distance between the consecutive planes in a cubic crystal is 2A0, then the la ttice parameter is______________.


25. Gamma rays are high energy neutrons 14) The resistance of a pure semiconductor at zero Kelvin is infinite.

15) A lattice is said to posses rotation symmetry if it is left unchanged after rotating through an angle ? about an axis.

16) There is five fold rotation axis in a lattice.

SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE.] 17) State the postulates of Bohr atom model. 18) Show that the binding energy varies with mass numbers of different nuclei. 19) Show the relation between decay constant and half life. 20) State Pauli’s exclusion principle. 21) What do you meant point groups and space groups? 22) With suitable diagram describe the diamond structure. 23 Derive Bragg’s law. 24) What are the special features of zener diode? 25) Distinguish between dc and ac load lines. 26) Draw the circuit diagram of a single stage common emitter amplifier. 27) What is binary number system? How does it differ from decimal number system? 28 What is Boolean algebra? Discuss the fundamental laws of Boolean algebra. SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] 29) The binding energy per nucleon for C12 is 7.68 MeV and that of C13 is 7.47 MeV.

Calculate the energy required to remove one neutron from C13. 30) Calculate the radio active decay constant for an element whose half life is 20

years. 31) Calculate the interplanar spacing for a (321) plane in a simple cubic lattice whose

lattice constant is 4.2 x 10-10 m

123

32) A transistor is connected in the CE configuration. The collector supply voltage is 10 V and the voltage drop across the 500 O connected in the collector circuit is 0.6 V. If a = 0.96, find (a) collector emitter voltage (b) base current, and (c) the emitter current.

33) The activity of a radioactive substance decreases to 1/64 of the original value in 21 years. Calculate the half life of the substance.

34) In a transistor circuit, the collector load is 4kO and the zero signal collector current is 1 mA. Determine the Q point if (a) Vcc = 10 V (b) Rc = 5 kO

35) A 9 V voltage regulated supply is required to run a car stereo system from 12 V battery. A zener diode with Vz = 9 V and Pmax = 0.25 W is used as a voltage regulator. Find the value of the series resistor.

36) Convert 359.310 to octal. SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37) State and explain the quantum numbers associated with the vector atom model. 38) Describe briefly the various methods for crystal structure determination by X-ray

diffraction. 39) Explain the terms ‘rectifier efficiency’ and ‘ripple factor’. Draw the circuit

diagram of a full wave bridge rectifier and explain its working.


Model Question Paper PY1131.5 – Mechanics and Properties of matter (For Home Science Main)

Time 3 hours Total weightage: 30 SECTION A [This section contains four bunches each of FOUR questions. Answer ALL questions. Each bunch carries a weightage of ONE] I1) Moment of inertia of a solid sphere of mass M and radius R about an axis passing through its tangent is a) 5/7 MR2 b) 7/5 MR2 c) 2/5 MR2 d) 5/2 MR2 2) The angular velocity of a rotating body is doubled. What happens to its K.E.? a) Doubled b) halved c) becomes 4 times d) no change 3) Which one of the following is not a S.H.M? a) Oscillations of a loaded spring b) Vibrations of atoms c) Motion of the minute hand of a clock d) Vibrations of a tuning fork

124

4) The bending moment for a beam of circular cross section of radius ‘r’ is a) (Ypr2)/R b) (Ypr4)/4R c) (Ypr2)/R2 d) (YpR4)/r II 5) The expression for energy density for a plane progressive wave of amplitude ‘a’ and frequency ‘n’ through a medium of density ‘d’ is a) 2p2a2n2d2 b) 2pa2n2d c) 2p2a2n2d d)2p2a2n2d2 6) The excess of pressure inside a cylindrical drop is a) 2s/r b) s/r c) 4s/r d) s/2r 7) In a simple harmonic oscillation P.E. and K.E. becomes equal at a) x=2a b) x =a/2 c) x = a/v2 d) x = 0 8) The angle of contact of mercury with glass is a) 90 b) obtuse c) acute d) zero III 9) When a body with circular symmetry roll on a plane surface the total kinetic energy of the body is the sum of …………………………. 10) The apparatus used to find the rigidity modulus of the material of a body in the form of a rod is …………………………. 11) The acceleration of a harmonic oscillator is maximum at its ……….. position. 12) The viscosity of a gas ………….. with temperature. IV (state whether the following statements are true or false) 13) The moment of inertia of a body is independent of its angular velocity. 14) The total energy of a harmonic oscillator varies with displacement when it executes simple harmonic motion 15) When a spherical body falls through a highly viscous liquid the terminal velocity of the body is inversely proportional to square of its radius. 16) The surface tension of a liquid increases with temperature. . SECTION B [Answer any EIGHT questions. Each question carries a weightage of ONE] . 17) State and prove theorem of parallel axis. 18) A person can distinguish between a raw egg and a hard boiled egg by spinning each one the table. Explain how? 19) Give expressions for kinetic, potential and total energy of particle executing simple harmonic motion. Represent them graphically. 20) Draw a typical potential energy curve for a diatomic molecule. 21) Write down the expression for velocity of transverse waves in a stretched string. Explain the different modes of transverse vibrations in string. 22) What is an I section girder? Why are I section girders preferred? 23) Explain the terms neutral axis, plane of bending and bending moment? 24) Distinguish between flexural rigidity, and torsional rigidity. 25) Name the factors on which the period of oscillation of a torsion pendulum

125

depends? 26) What is a Neumann’s triangle? Explain its significance. 27) Calculate the force required to separate two plates enclosing a thin layer of water. 28) If the length of the capillary tube in Poiseuille’s experiment is doubled and radius halved, how will it affect the rate of flow of liquid? . SECTION C [Answer any FIVE questions. Each question carries a weightage of TWO.] . 29) A circular disc of radius 0.1 m and mass 1 kg. is rotating at the rate of 10 rps about its axis. Find the work that must be done t increase the rate of revolution to 20 rps. 30) Show that the kinetic energy of a uniform ring of mass ‘m’ rolling along a smooth horizontal surface so that its centre of mass has a velocity ‘v’ is mv2. 31) A particle executing simple harmonic motion has a maximum velocity 0.3 m/s. and acceleration 0.4 m/s2. Find the amplitude and period of oscillation. 32) A plane progressive wave in a medium is represented by the equation y=0.2sin (5p t-(5/16)px) where x and y are in cm and t in seconds. 33) A bar 1 m long and 5 mm square in section supported horizontally at its ends and loaded at the middle is depressed 1.96 mm by a load of 100 grams. Calculate Young’s modulus for the material of the bar. 34) What couple must be applied to a wire 1 m long and 3 mm diameter to twist one of its ends through 45 degree while the other end is fixed? n = 5 x 1010 Nm-2 35) The pressure of air inside a soap bubble of radius 10-2 m is balanced by that due to a column of oil 2 x 10-3 m high. Find the surface tension of soap solution. Density of oil 0.8 x 103 kgm-3. 36) A liquid flows through two capillaries under the same pressure head. The lengths of the tubes are in the ratio 2: 3 and their diameters in the ratio 2 : 3. Compare the rates of flow of the liquid in the two tubes. . SECTION D [Answer any TWO questions. Each question carries a weightage of FOUR] 37) Derive an expression for the moment of inertia of a solid sphere about a tangent. 38) Derive the differential equation of a particle executing simple harmonic motion. Derive expressions for velocity and acceleration for a S.H.M. 39) What is a cantilever? Derive an expression at the free end of a cantilever clamped at one end and loaded at the other end.

126


Model Question Paper PY1231.5 – Thermal Physics (For Home Science Main only)


I. 1. Compared to ordinary light waves, the wavelength of thermal radiations is

(a) Larger (b) Smaller (c) Equal (d) None of these

2. An ideal material for making cooking vessels must have

(a) Small conductivity and large heat capacity (b) Large heat capacity and large

conductivity (c) Small heat capacity and large conductivity

127

(d) Small heat capacity and small conductivity

3. The total energy radiated per second from unit area of a black body is

proportional to

(a) T (b) T2 (c) T3 (d) T4



II. 5. Let dW be the work done by a gas and dV be its change in internal energy. If

dW+dV=0, the process is

(a) Isothermal (b) Adiabatic (c) Isochoric (d) Cyclic






8. During an adiabatic process which of the following remains constant

(a) Pressure (b) Volume (c) Temperature (d) Entropy



11. The process in which the pressure remains constant is called __________.



128








18. Derive the differential equation for diffusion.

19. State and explain Fick’s law of diffusion.

20. Explain why Lee’s disc method is not suitable for conductors.



23. How will you estimate the temperature of the sun by knowing solar constant?



26. Show that there is always an increase of entropy in an irreversible cycle.

27. Entropy of the universe tends to a maximum. Explain



29. A slab consists of parallel layers of iron and copper 5cm and 7cm thick and

thermal conductivities 500 W/m/K and 385 W/m/K respectively. If the

129

opposite faces of the slab are at temperatures 373K and 273K, find the

temperatures of the interface.



31. Two litres of hydrogen at a pressure of 105 Pa expands adiabatically to 1.5

times the initial volume. Find the work done. ? = 1.4




33. A Carnot engine whose sink is at 200K has an efficiency 40%. It is desired to

increase the efficiency to 50%. By how much should the temperature of the

source be increased?




kJ/kg.



steam = 2.26×106 J/kg.

36. Calculate the change in entropy when 100 grams of water at 150C is mixed

with 160 grams of water at 400C.

130

SECTION D [Answer any TWO questions. Each q uestion carries a weightage of FOUR]








B.Sc Degree Programme in (Complementary) Physics Model Question Paper

PY1331.5 – Optics and Electricity (For Home Science Main only)


I. 1. A device based on interference due to division of amplitude is

(a) Biprism (b) Newton’s rings (c) Double mirror (d) None of these


(a) Interference (b) Diffraction (c) Polarisation (d) Dispersion


131








(d) None of these

6. In an electric fan ……………………………………………….

(a) Electrical energy is converted into Mechanical energy.

(b) Mechanical energy is converted into Electrical energy.

(c) No energy conversion.



(a) 00 (b) 450 (c) 900 (d) 1800




maxima are ____________.





132


light.




SECTION B

[Answer any EIGHT questions. Each question carries a weightage of ONE.]



and parallel.




22. Explain the principle of working of a microwave oven.




26. Distinguish between spontaneous emission and stimulated

emission.



133


29. In a biprism experiment 100 fringes were observed with 600 nm

light. How many fringes will be observed if the wavelength is

changed to 500 nm and the set up remains unchanged?

30. Light of wavelength 593 nm falls normally on a thin wedge shaped

film of refractive index 1.4 forming fringes that are 1 mm apart.

Find the angle of the wedge.

31. In a Newton’s rings arrangement the diameter of the 4th and 12th

dark rings are 4 mm and 7 mm respectively. Find the diameter of

the 20th dark ring.

32. A lens of focal length 40 cm forms a Fraunhofer diffraction pattern

of a slit of 0.2 mm width. Calculate the distance of the first dark

band from the axis for light of wavelength 589 nm.

33. A plane transmission grating has 6000 lines/cm over a length10

cm. Find the resolving power of the grating and the smallest

wavelength that can be resolved in the 600 nm wavelength region.

34. A capacitor of capacity 0.1 µF is connected with an inductance of 1

mH. Calculate the natural frequency of the circuit.

35. Find the value of the inductance that should be connected in series

with a capacitor of 5 µF, a resistance 100 O and an ac source of

frequency 50 Hz so that the power factor is unity.

36. A magnetic field of 0.5 T is applied to a paramagnetic gas whose

atoms have an intrinsic magnetic dipole moment of 1.2×10-23J/T.

At what temperature will the mean kinetic energy of translation of

the gas atoms be equal to the energy required to reverse a dipole

end for end in this magnetic field.

SECTION D


134

37. Describe with necessary theory, an experiment to determine the

wavelength monochromatic light using Newton’s rings

arrangement.

38. Describe the phenomenon of Fresnel diffraction at a straight edge.

Give an example for the same.

39. Derive an expression for the current in a series LCR circuit when

an alternating voltage is applied on it. Obtain the condition for

resonance.


Model Question Paper PY1431.5 – Atomic Physics and Electronics (For Home Science Main only)


I. 1. The presence of sharp lines in the spectrum of a gas indicates

(a) Discrete energies associated with stationary orbits (b) Electron emits energy

in discrete packets (c) Light consists of photons

(d) Electrons collide each other




3. Balmer series in hydrogen spectrum is emitted when electrons jump from higher

orbits to

135

(a) First orbit (b) second orbit (c) third orbit (d) fourth orbit

4. Spin quantum numbers of an electron can have

(a) Only half integral values (b) only integral values

(c) Only one constant value (d) integral and half integral values



(d) None of these







(d) None of these

III. 9. One of the features of vector atom model is ___________ quantization.





13. ? radiations are electromagnetic radiations of high frequency.


15. The mass of an electron is entirely due to its charge.


SECTION B

[Answer any EIGHT questions. Each question carries a weightage of ONE.]

17. What is Bohr’s correspondence principle?


19. What is critical magnetic field?

136




23. Explain Meissner effect.


25. Distinguish between type I and type II super conductors.




SECTION C

[Answer any FIVE questions. Each question carries a weightage of TWO.]

29. A radioactive substance has a half life of 30 days. Calculate the

time taken to decay 25% of the given sample of the substance.

30. The binding energy per nucleon for C12 is 7.68 MeV and that of C13

is 7.47 MeV. Calculate the energy required to remove one neutron

from C13.

31. The wavelength of a line in hydrogen spectrum is 500 nm. Find out

the related energy change of the in electron volt.

32. Calculate the energy difference between the ground state and the

first excited state for an electron in a one dimensional rigid box of

length 1 A0.

33. What is the lowest energy that a neutron of mass 1.67×10-27 kg can

have if it is confined to move along the edge of an impenetrable

box of length 10-14 m.

137

34. In a canter tapped full wave rectifier maximum voltage across half

of the secondary winding is 50 V. If the load resistance is 200O,

calculate the dc output voltage and the peak inverse voltage.

35. A 10 Volt Zener diode along with a series resistor is connected

across a 40 V supply. Calculate the minimum resistance required if

the maximum Zener current is 50 mA.

36. In a transistor amplifier, when signal changes by 0.02 V, the base

current changes by 10 µA and the collector current changes by 18

mA. If the collector load RC = 5 kO and RL = 10 kO, find the

current gain and voltage gain.

SECTION D


37. Derive the general equation of growth and decay of radioactive

series. Explain secular and transient radioactive equilibrium.

38. Obtain Schrödinger wave equation for a particle in a one

dimensional rigid box. Solve it to obtain eigen functions and show

that eigen values are discrete.

39. Explain the rectifying action of a p-n junction diode. With the help

of a neat circuit diagram, explain the working of a full wave

rectifier using two diodes.

138

UNIVERSITY OF KERALA B.Sc Degree Programme in (Complementary) Electronics

Model Question Paper EL1131- Electronics I (For Physics Main only)


I. Choose the most appropriate one.

1. A 100 ? resistor is to be used in a circuit carrying a current of 0.5 A. Its power rating should be

(a) 50 W (b) 25 W (c) 200 W (d) 500 W

2. Ferrite cores commonly used at high frequencies

(a) increase core losses (b) decrease core losses

(c) decrease inductance (d) increase resistance

3. The main purpose of laminating a transformer core is to decrease its

(a) electrical resistance (b) reluctance (c) eddy current loss

(d) hysteresis loss

4. The leakage current of semiconductor diode is caused by

139

(a) chemical energy (b) barrier voltage (c) heat energy (d) doping

impurity

II. Choose the most appropriate one.

5. The superposition theorem is essentially based on the concept of

(a) duality (b) linearity (c) reciprocity (d) non-linearity

6. Rating of a battery is usually expressed in

(a) watt-hour (b) joule (c) ampere-hour (d) ampere

7. The power in an ac circuit is given by

(a) VI Cos f (b) VI Sin f (c) I 2R (d) I 2Z

8. The turn-on voltage of Germanium junction diode is nearly

(a) 0.7 V (b) 0.3 V (c) 0.1 V (d) 1 V

III. Fill in the blanks with most appropriate word or numerical value.

9. The total resistance of a parallel circuit is always --------------- than the lowest resistance

connected in any of its branches.

10. A ----------------- cell is one that cannot be recharged.

11. The time period of a sine wave of 1 kHz is ------------- millisecond.

12. An ideal diode conducts in forward direction with ------------ resistance.

IV. State whether the following statements are true or false. 13.

If voltage across a resistor is doubled, its power dissipation is quadrupled.

14. When connected in series, all capacitors have the same charge but different

voltages.

15. The time constant of a series R-L circuit can be doubled by doubling the value of

R.

16. Holes are as mobile as electrons.


17. What is a non-linear resistor? Give one example.

18. State Kirchhoff’s current law and voltage law.

140

19. What is meant by capacitance of a capacitor? What are the factors controlling

capacitance?

20. State maximum power transfer theorem.

21. What is magnetic shielding?

22. What is reluctance in a magnetic circuit? Write the expression for reluctance from Ohm’s

law.

23. Explain the terms ‘peak value’ and ‘peak to peak value’ in relation to a

sinusoidal current.

24. Explain skin effect.

25. Distinguish between intrinsic and extrinsic semiconductors.

26. Explain the formation of depletion layer in a PN junction.

27. Distinguish between zener breakdown and avalanche breakdown.

28. Draw the circuit of a +ve clipper and explain the working.


29. In the series voltage divider circuit given, the rated load current is 2 mA and maximum

current the battery can supply is 10 mA. Calculate the values of resistances R1 and R2 and

their power ratings.

30. Using Kirchhoff’s laws find the magnitude and direction of current flow through the 10 ?

141

resistor in the figure.

31. A capacitor is charged by a 100 V battery. If its capacitance is 900 pF, calculate the energy

stored in it. Also calculate the loss of energy when this capacitor is disconnected from the

battery and connected to another identical capacitor.

32. A magnetic circuit consists of an iron ring of mean circumference 80 cm with cross-

sectional area 12 cm2 throughout. A current of 2 A in the magnetizing coil of 200 turns

produces a total flux of 1.2 mWb in the iron. Calculate (i) flux density in iron (ii) absolute

and relative permeability of iron and (iii) reluctance of the circuit.

33. A low-voltage soldering rod taking 40 A at 12 V is to be operated from the secondary of a

240 V transformer. Calculate (i) turn ratio of the transformer and (ii) primary

current.

34. In tone control circuit of a receiver, a 1 k? resistor is joined in series with a 0.1 µF

capacitor. Calculate the impedance of the combination at 2 kHz and 10 kHz.

35. Explain the three major types of atomic bonds involving valance electrons.

36. At room temperature, copper has free electron density of 8.4 × 1028 per m3. Find the drift

velocity of free electrons at room temperature in a copper conductor having cross-sectional

area 10-6 m2 and carrying a current of 5.4 A.


142

37. State and explain Thevenin’s theorem. Explain with an example how you would Thevenize a circuit.

38. What is a transformer? Explain its working. Describe the different types of transformers used in electronic circuits.

39. Define frequency, amplitude and phase of an ac signal. Derive an expression for the RMS value of an ac signal.


Model Q uestion Paper EL1231- Electronics II (For Physics Main only)



1. The process of selecting the desired frequency from a composite wave is called

(a) tuning (b) filtering (c) rectification (d) modulation

2. The value of zener current is

(a) is limited by external circuit resistance (b) determined by zener voltage

(c) totally independent of temperature (d) always in µA range

3. When the E/B junction of a transistor is reverse biased, collector current

(a) is reversed (b) increases (c) decreases (d) stops

4. The ripple factor of a bridge rectifier is

(a) 0.482 (b) 0.406 (c) 0.812 (d) 1.21

143

II. Choose the most appropriate one. 5. The capacitance of a varactor diode can be changed by

(a) increasing its doping level (b) changing its forward bias (c)

changing the

barrier potential (d) changing the reverse voltage

6. The colour of light emitted by a LED depends on

(a) its forward bias (b) its reverse bias (c) the amount of forward

current

(d) the type of semiconductor material used

7. Improper biasing of a transistor circuit leads to

(a) excessive heat production at collector terminal (b) distortion in output

signal

(c) faulty location of load line (d) heavy loading of emitter terminal

8. In a single stage CB amplifier, a smaller load resistance RL will produce

(a) high current gain (b) low voltage gain (c) better frequency

response

(d) higher power gain


9. ...…………. diode is often referred to as hot carrier diode.

10. A photodiode is essentially a --------- biased P-N junction which is illuminated

with radiation.

11. The leakage currents in a transistor are due to ---------------- carriers.

12. Voltage gain of an emitter follower is nearly ---------------.


13. A sine wave can be converted into a square wave with the help of zener diodes.

14. The voltage regulation of a p filter is inferior to that of an L-C filter.

15. If Q-point is located near the cut-off point, the negative signal swing gets

clipped first.

16. Of all the h parameters, ho has the smallest magnitude.

144


17. What is a low-pass filter? Draw the simple circuit of a low-pass filter.

18. What is a tunnel diode? Draw its I-V characteristic.

19. What are thermistors? Mention their applications.

20.Show that the maximum rectification efficiency of a half wave rectifier is 40.6 %

21. Obtain the relationship between a and ß of a transistor.

22. Define stability factor. Which biasing circuit has maximum stability factor?

23. What do you understand by thermal runaway in a power transistor?

24. State the ß rule of a transistor circuit.

25. What is a load line? Distinguish between DC load line and AC load line.

26. Write down the procedures for drawing AC equivalent circuit of a transistor

amplifier.

27. Explain the effect of source resistance on voltage gain.

28. What are h parameters? Why are they called so?


29. An RLC circuit consists of R = 80 ? , L = 40µH and C = 0.0783 pF. Find its

(i) resonant frequency (ii) Q-factor and (iii) band width.

30. Draw the circuit of a transistor shunt voltage regulator and explain its working.

31. A single phase half wave diode rectifier supplies power to a 2 k? resistive load. The input

ac supply voltage has a peak value of 300 V. Neglecting forward drop of the diode, calculate

(a) Vdc (b) Idc (c) power delivered to the load (d) ripple voltage (rms value).

32. The following measurements are made in a transistor: IC = 5.202 mA, IB = 50 µA,

ICO = 2µA. Compute the values of a, ß and IE.

145

33. In a controlled half wave rectifier, peak supply voltage is 200 V and the value of the load

resistance is 1 k? . Calculate the power delivered to the load for firing angles of (a) 0?,

(b) 45?, (c) 90? and (d) 135?.

34. In a CE amplifier circuit with voltage divider bias arrangement, the various parameters are

RL = 1 k? , RE = 2 k? , R1 = 10 k? , R2 = 5 k? , VCC = 12 V and VBE = 0.7 V. Find the

operating point.

35. For the circuit shown in figure, calculate (i) IC(sat), (ii) actual IC, VCE and draw the DC load

line.

36. A junction transistor has re = 50 ? , rb = 1 K, rc = 1 M and a = 0.98. It is used in common

base circuit with a load resistance of 10 K. Calculate the current, voltage and power gains

and the input resistance.


37. Explain a full wave bridge rectifier. Derive equations for ripple factor and efficiency.

146

38. Explain the input and output characteristics of a transistor in common emitter configuration and the determination of ß, Rin and Rout of the transistor from these.

39. Define h -parameters for a linear circuit. Explain how they are calculated for an ideal common emitter amplifier.


Model Question Paper

EL1331- Electronics III (For Physics Main only)



1. CE amplifier is characterized by

(a) low voltage gain (b) moderate power gain (c) signal phase reversal

(d) very high output impedance

2. The common mode-rejection ratio of an ideal differential amplifier is

(a) zero (b) infinity (c) less than unity (d) greater than unity

3. Which semiconductor device acts like a diode and two resistors?

(a) SCR (b) triac (c) diac (d) UJT

4. One of the serious disadvantages of FM is its

147

(a) limited line-of-sight distance (b) expensive equipment

(c) adjacent channel interference (d) high static noise

II. Choose the most appropriate one. 5. The outstanding characteristic of a direct coupled amplifier is its

(a) temperature stability (b) avoidance of temperature-sensitive

components

(c) utmost economy (d) ability to amplify direct current and low frequency

signals

6. A JFET has the disadvantage of

(a) being noisy (b) having small gain-bandwidth product

(c) possessing positive temperature coefficient (d) having low input

impedance

7. A relaxation oscillator is one which

(a) produces non-sinusoidal output (b) relaxes indefinitely

(c) has two stable states (d) oscillates continuously

8. For sustaining oscillations in an oscillator

(a) feedback factor should be unity (b) phase shift should be 0° or np

(c) both (a) and (b) (d) feedback should be negative


9. A Darlington pair provides a very high value of ------------ not provided by any

single transistor.

10. In a JFET, drain current is --------------- when VGS = 0.

11. Positive feedback is often used in ------------- circuits.

12. The Schmitt trigger is often called a ---------------- circuit


13. A class B amplifier has highest output impedance and lowest input impedance.

148

14. Coupling and bypass capacitors of an amplifier determine its lower cut-off

frequency.

15. A crystal oscillator needs no tuned circuit.

16. In AM transmission, bandwidth is determined by carrier frequency.


17. What is cross-over distortion in class B push-pull operation?

18. Explain noise and noise factor.

19. Write any two advantages of transformer coupling.

20. What are the characteristics of the decibel system?

21. Explain Miller effect.

22. Define gain bandwidth product.

23. Sketch the circuit diagram of a current series feedback amplifier.

24. Define transconductance and AC drain resistance of a JFET.

25. Draw the characteristics of a UJT and explain the negative resistance region.

26. What is piezo-electric effect?

27. What are the advantages of frequency modulation over amplitude modulation?

28. Diode detectors are extensively used in AM broadcast receivers. Why?


29. A class A power amplifier has a transformer load. If the transformer has a primary to

secondary turns ratio of 10 and a secondary load of 16 ? , calculate the maximum a. c.

output power. Given that ICQ = 100 mA.

30. What is RC coupling? Draw the circuit of a two stage RC-coupled amplifier. Mention the

advantages of RC coupling?

149

31. A certain radio receiver delivers an output power of 3.6 W. (i) What would be the decibel

gain if power output is increased to 7.2 W? (ii) What power output would be required to

produce a power gain of 10 dB?

32. An amplifier has a gain of 1000 without feedback. Find the feedback factor required to

reduce the gain to 400.

33. For an N-channel JFET, IDSS = 8.7 mA, VP = – 3 V, VGS = – 1 V. Evaluate ID, gmo

and gm.

34. A silicon UJT has an interbase resistance of 10 K. It has RB1 = 6 K with IE = 0. Find UJT

current if VBB = 20 V and VE is less than VP. Find also ?, the intrinsic stand-off ratio.

35. In a Colpitt’s oscillator, the following component values are given; C1 = 0.01 µF, L = 15 µH.

The oscillating frequency is 7500 Hz. Find the value of capacitor C2.

36. An audio signal of 3 kHz is used to modulate a carrier wave. Calculate the frequency of the

carrier wave, upper side band frequency and bandwidth, if the lower side band frequency is

497 kHz.


37. What is a Darlington pair? Obtain expressions for current gain, voltage gain input

impedance. Also enlist its advantages.

38. What are multivibrators? Explain the working of an astable multivibrator with a neat diagram. Deduce the expression for frequency.

39. What is the need of modulation? Explain the principle of amplitude modulation. Derive an equation for amplitude modulated wave.

150


Model Question Paper

EL1431- Electronics IV (For Physics Main only)



1. The binary addition 1 + 1 +1 gives

(a) 111 (b) 10 (c) 110 (d) 11

2. Which of the following is not an octal number?

(a) 19 (b) 77 (c) 15 (d) 101

3. Noise margin is expressed in

(a) decibel (b) watt (c) volt (d) phon

151

4. Amongst different types of fibres, single-mode step-index fibre has

(a) highest data rate (b) lowest attenuation

(c) highest thickness (d) both (a) and (b)

II. Choose the most appropriate one.

5. When an input electrical signal A = 10100 is applied to a NOT gate, its output

signal is

(a) 01011 (b) 10101 (c) 10100 (d) 00101

6. An XOR gate produces an output only when its two inputs are

(a) high (b) low (c) different (d) same

7. The operation of a Q-meter is based on

(a) Self-induction (b) series resonance

(c) Mutual induction (d) eddy currents

8. The main energy losses in an optical fibre consist of

(a) material loss (b) loss due to light scattering (c) bend loss (d) all of

the above


9. The open-loop gain of an ideal Op-amp is ---------------.

10. The decimal fraction of 0.75 corresponds to the binary fraction of ------------.

11. The ---------------- gate is also called any-or-all gate.

12. A microphone is an example of --------------- transducer.


13. In binary numbers, shifting the binary point by one place multiplies or divides it

by 2.

14. A bubbled OR gate is equivalent to a NAND gate.

15. As in ordinary algebra Boolean variables can also take on any value including

zero.

16. Current sensitivity of a meter depends on the current passing through it.

152


17. What are the merits and demerits of integrated circuits?

18. What is common mode rejection ratio of an Op-amp?

19. Find the 1’s and 2’s complement of binary number 11101100.

20. Convert 105.1510 to binary using the double-dabble method.

21. Draw the circuit of a half adder and give its truth table.

22. State and explain De Morgan’s theorems.

23. Explain fan-in and fan-out of a of a logic family.

24. What is a strain gauge? What is its working principle?

25. What are the advantages of VTVM over multimeter?

26. What is a linear variable differential transformer (LVDT)?

27. What is meant by dispersion in optical fibres?

28. What are the applications of optic fibres?


29. Find the output voltage of the inverting Op-amp adder with the values indicated as

input.

30. Convert the hexadecimal number AF9.BOD into octal form.

31. What is a NOR gate? Give its symbol and truth table. Explain why it is often

referred to as a universal gate.

32. Prove the following identities (i) AB + A = A (ii) A + = A + B

153

33. A metallic strain gauge with a gauge factor K = 2 is bonded to a steel member

which is subjected to a stress of 10.5 × 109 N/m2. If the modulus of elasticity for

steel is 21 × 1012 N/m2, calculate the fractional change in the resistance of the

gauge due to the applied stress.

34. A meter has 20 ? internal resistance and gives full scale deflection for 5 mA. The

meter is to be converted into a 5 A ammeter. Calculate the multiplying factor of

the shunt and the value of the shunt.

35. If the refractive index of the core of an optical fibre is 1.56 and that of cladding is

1.48, calculate the numerical aperture, critical angle and angle of acceptance.

36. An optical communication system uses a fibre having a loss of 5.6 dB/km. The

system uses a 100 km length fibre. Calculate output power, if the input power is

750 µW.


37. Draw the circuit diagrams of a differentiator and integrator using Op-amp and

explain their working. Also mention their uses.

38. Draw the block diagram of a CRO and explain the major subsystems. Write down

the expression for deflection sensitivity of CRT, in terms of tube parameters.

39. Discuss light propagation through an optical fibre. Also distinguish between

step-index and graded-index fibres.

Physics Question paper

Documents

section b

increases b

section c answer

maximum b minimum c

beam c thickness

beam d load

nsm2 b ns2m c nsm d

youngs modulus b breadth