Mohammed Asif Name : Roll No. : Topic : Ph : 9391326657, 64606657 2. MEASUREMENT OF PHYSIAL QUANTITIES 1. If a physical quantity P. is given by P = x + y i.e., % error in P = m. % error in x + n. % error in y. 4. Significant figure i) all non-zero digits are Significant Ex. 23.56 No. of s. f – 4 ii) Zero in between two nonzero digits are Significant Ex. 230405 No. of s. f – 6 iii) All zeros to the left of the first nonzero are not Significant Ex. 002356, 0.002356 No. of s. f – 4 Flat No.301, Rukkus & Yellus Arcade, Fever Hospital Road, Barkathpura, Hyd-00065. Ph: 040 – 64606657, 9391326657. www.asifiitphysics.vriti.com 1
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Mohammed Asif
Name :
Roll No. :
Topic : Ph : 9391326657, 64606657
2. MEASUREMENT OF PHYSIAL QUANTITIES
1. If a physical quantity P. is given by P = x + y
i.e., % error in P = m. % error in x + n. % error in y.4.
Significant figurei) all non-zero digits are Significant Ex. 23.56 No. of s. f – 4ii) Zero in between two nonzero digits are Significant Ex. 230405 No. of s. f – 6iii) All zeros to the left of the first nonzero are not Significant Ex. 002356, 0.002356 No. of s. f – 4iv) All zeros to the right of the last nonzero digit in a measured value are SignificantEx. 235600 m No. of s. f – 6
M – VIII: Application of triangle law:Boat and river:If the man wants to reach the exactly opposite point on the other bank (or) to cross the river along the shortest path, he has to swim along AC.
2. If the man wants to cross the river in shortest time.
a) Direction of motion of boat → Along the normal (or) 900 with direction of flow.
Rain and umbrella:Rain is falling vertically down wards with a velocity Vr and a man is moving horizontally with a velocity Vm (or wind is flowing with a velocity Vm). To protect himself from rain the man has to hold his umbrella at an angle Ө with vertical
Change in velocity:are the initial and final velocities of a body and Ө is the angle between
Relative velocityare the velocities if two bodies A and B respectively then
M – I: Freely falling body:1. Equations of motion:
M – II: Vertically projected body:1. Equations of motion:
(a) v = u – gt (b) h = ut - ½ gt2 (c) V2 = u2 – 2gh d) Sn =
2. Time of ascent.
5. A body thrown vertically upward with a velocity U crosses a point p in its path after
t1 sec while going up and after t2 sec while coming down, then
M – III: Body projected vertically upwards from the top of a tower:1. Equations of motion:(a) v = -u + gt (b) H = -ut + ½ gt2 (c) V2 = u2 + 2gH (d) Sn =
2. A balloon is moving upwards with uniform velocity U. A body is dropped from it
when it is it at a height H above the ground then,a) Velocity of the body after t sec V = -U + gtb) Time taken by the body to reach ground cane be found from H = -ut + ½
gt2
c) Separation between body and balloon after t sec = ½ gt2
d) Height reached by the body above ground =
3. A body thrown vertically upwards with a velocity u from the top of a tower reaches the ground in t1 sec. Another body thrown vertically downwards with
System like a rocket. 2. a) When a lift moves upwards with acceleration a (or) downwards with a
deceleration a then apparent weight of a body in the lift w = m (g + a). b) When a lift moves upwards with deceleration a (or) downwards with an
acceleration a, then apparent weight of a body in the lift w = m (g - a). c) When the lift is stationary or moving with uniform velocity the w1 = mg.
d) Percentage change in weight
e) If h is the depth of water in a bucket placed in the lift then pressure at the bottom of the bucket is P = hd (g a).
3. When a machine gun fires ‘n’ bullets in a time t then the force required to hold the gun is
.
4. a) When a metallic plate of mass m is held in mid air by firing ‘n’ shots/second with a
velocity u, if the bullets stop dead after striking the plate, then mnu = mg. b) If the shot comes back with a velocity V then nm (v+u) = mg.5. If water from a narrow pipe hits a wall horizontally with a velocity v and stops dead,
force acting on the wall
(volume flow rate).A = area of cross section of the piped = density of water.If water bounces back with same speed F = 2 Adv2
6. If a ball hits a wall normally with a velocity v and rebounds with same velocity change
in momentum = 2 mv.
Force acting on the wall where ‘t’ is the time of collision.
7. a) A body of mass m, moving with a velocity v hits wall and rebounds with same
velocity, then change in momentum perpendicular to the wall force
on the wall
b) Change in momentum parallel to wall = 0.8. Extra force required to keep the conveyor belt moving with a velocity V when
9. If hot gases are coming out of the rocket at the rate of with a velocity V
then
a) Thrust on the rocket
b) If the rocket moves up with uniform velocity then F = MgM → mass of the rocket.
c) If the rocket moves up with uniform acceleration a then F = M(g + a).If gravity is neglected then F = Ma
d) Acceleration of the rocket after t sec a
LAW OF CONSERVATION OF LINEAR MOMENTUM AND COLLISIONS
M – I: Law of conservation of momentum:A body of mass m1 moving with a velocity u1 collides with another body of mass m2 moving with a velocity u2, if v1 and v2 are their final velocities then According to law of conservation of momentumm1 u1 + m2 u2 = m1 v1 + m2 v2
If the two bodies stick together after collision then common velocity
1. If bodies are moving in mutually perpendicular directions before collision then
common Velocity
2. In case of obliquic collision i.e., after collision, if the direction of motion of bodies
makes an angle with initial directiona) = (
b) 3. If a bullet of m come out with a velocity from a gun of mass M the Recoil velocity
4. If a stationary shell breaks into two fragments, they will move in opposite directions, with velocities in the inverse ratio of their masses.
5. In the above case, the Kinetic energy of the two fragments is inversely proportional
to their masses.
6. The total energy released in the explosion
7. If a shell at rest explodes into three fragments having masses in the ratio m1 : m2 : M3 if first two fragments travel in mutually perpendicular direction with velocities v1 and v2 then the velocity of the third fragment is given by
8. If a shell of mass m moving with a velocity explodes into two fragments having
masses m1 and m2 and if are the velocities of the fragments then
M – II: Elastic collision:1. For one dimensional elastic collision v2 – v1 = u1 – u2.
Special casesa) When m1 = m2; v2 = u1, v1 = u2.b) If u2 = 0, (i.e. second body is at rest)then
If m1 = m2 fraction of KE transferred is maximum and that is 100 %.M – III: In elastic collision:1. a) =
b)
Final velocity can be found by using above two equations
2. If u2 = 0 i.e., if the second body is at rest ratio of final velocities
4. A block of mass M is suspended freely. A bullet of mass m is fired in to the block with a velocity . If the bullet gets embedded in to the block then
a) Velocity of block after collision
b) Height rised by the block
c) Maximum angle made by the block with vertical cos
d) Loss of K.E
M – IV: Coefficient of Restitution:
1. Coefficient of restitution
a) When a body falls from a height h, and rises to a height h1 after first collision
M – I: Work:1. a) If a force ‘F’ acts on a body making an angle with horizontal and
displaces the body through a distance ‘S’ work done,
(If F and S are same).
(If F and t are same).2. Work done against gravity W = mgh.
3. Work done in imparting velocity to a body
4. Work done against friction on a level surface.
5. Work done in compressing or elongating a spring
K – spring constant x – elongation6. Work done in moving a body up on to a smooth inclined plane is W = (mg sin
) S.7. Work done to compress or expand a gas at constant pressure.8. a) Work done in pulling the bob of a simple pendulum aside through an angle
from the vertical is
m – mass of the bob l- length of pendulum b) Work done in displacing the pendulum from an angle to an angle is
9. Work done in pulling aside a bar through an angle from the vertical is
m – mass of the rod l- length of the rod10. The work done in lifting a body of mass ‘m’ and density ‘ds’ in a liquid of density ‘d1’ through a height ‘h’ under gravity is
11. Work done by external resultant force on a body is equal to change in KE of the body
12. Work done in lifting water from a well from a well of depth h is
m→ Mass of water m0→ Mass of rope13. A rod of mass m and length l lies horizontally on a ‘floor’. The work done in rotating
the rod through an angle about one edge in a vertical plane is given W = ½ mgl sin .
14. In the above point, the work done in bringing the rod to vertical position is W = ½ mgl.15. A uniform chain of length l and mass m is placed on a friction less table such that
1/nth of its length hanging over the edge. The work done in pulling the hanging part
on to the table is
M – II: Power:1. Average power P = W/t.2. Instantaneous power = F x V = 3. The power of machine gun firing ‘n’ bullets, each of mass ‘m’ in one second with
velocity ‘v’ is
4. A motor sends a liquid with a velocity ‘V’ in a tube of cross section ‘A’ and ‘d’ is the
density of the liquid, then the power of the motor is
5. A motor lifts m kg of water to a height h in t sec. Then the power of the motor is
.
If is the efficiency of the motor then
If the water comes at of the pipe with a velocity then
6. Extra power required to keep a conveyor belt moving with constant velocity if
gravel is falling the belt at a rate of dm/dt is
7. A vehicle moves with a constant velocity V on a rough horizontal road. The frictional
force acting on the vehicle is f then the power o f the engine P= f x v.
M – III: Energy:1. KE = ½ mv2.2. PE = mgh.3. PE of a liquid in a capillary tube PE = (d) (ah) g h/2 = dagh2 / 2.
d – density of liquida – area of cross section of the capillary tube.h – height of the liquid in the capillary tube.
4. PE of a block placed on the ground =
5. P.E in a spring = ½ kx2 .M – IV: Law of conservation of energy:1. A body is dropped freely from a height h, during collision with ground it looses x %
of energy and then rises to a height ‘h’ then
(100-x) remaining energy;
2. In the above question if the body is thrown vertically downwards with a velocity V
then
3. A body of mass m is dropped from a height h on to a spring of spring constant K.
If x is the compression produced in the spring then
If x < < < h mgh = ½ kx2
4. A body of mass m moving with a velocity V collides with a spring of spring constant
K and comes to rest. If x is the compression produced in the spring then½ mv2 = ½ kx2
M – V: Work – Energy theorem:1. Work done = Change in KE;
F x S = ½ m (V2 - u2 ).2. A body of mass m is dropped from a height h it reaches the ground with a velocity
work done by air resistance W = mgh – ½ mv2 .
3. A knife edge of mass m is dropped from a height h on to a table. It penetrates a
M – I: Coordinates of center of mass:1. Particles distributed in space. If (x1y2z1) - (x2y2z2) – are the position coordinates
of particles of masses m1, m2 – the position coordinates of their center of mass
are
2. In vector notation. If r1, r2, r3….. Are the position vectors of particles of masses m1, m2, m3…… Then the position vector of their center of mass is
M – II: Velocity Center of Mass:3. a) Velocity of center of mass
If are the velocities of particle of masses.m1, m2, m3…… mn the velocity of their center of mass is
i.e., total momentum of the system is the product of mass
of the whole system and the velocity of the center of mass.c) If V1 and V2 are the magnitudes of velocities of two particles of masses
d) If two particles of masses m1 and m2 are moving with velocities V1 and V2 at
right angles to each other, then the velocity of their center of mass is given
by
M – III: Acceleration of center of mass:4. a) if a1, a2, a3 ….an are the acceleration of particles of masses m1, m2, m3…… mn
Then the acceleration of their centre of mass is
If a1 and a2 are the magnitude of acceleration of two particles of masses m1 and m2 then the magnitude of acceleration of their centre of mass.
(If they are moving at right angles to each other)
M – IV: Two particle system:5. Position of centre of mass:
Two particles of masses m1 and m2 are separated by a distance ‘d’. If x1
and x2 are the distance of their center of mass from m1 and m2 thenm1 x1 = m2 x2
If m1 is moved through a distance towards the c.m and m2 is also moved
through a distance towards the c.m the position of c. m remains same if
m1 = m2
6. Out of a uniform circular disc of radius R, if a circular sheet of radius r is removed, the centre of mass of the remaining part shits by a distance
if r =R/2 then x = R/6
7. Out of a uniform solid sphere of radius R, if a sphere of radius r is removed, the
M – I: Motion on the horizontal plane:1. Limiting friction = fL = fs (max) =
Normal reaction N = mgKinetic friction fk = Rolling friction fR = . FL > fK > fR
2. If F = 0, f = fs = 0 → Body does not slide.F < fL f = fs = F→ Body does not slide.F = fL f = fL = F – Body is just ready to slideF>fL f = fk – Body slides.
Here F = applied force (or) force that tries to displace the body, f = frictional force.3. Minimum force required to displace a body = fL= .4. minimum force required in displacing a body placed in a lift moving with
acceleration. if the lift is falling freely f = 0
5. If a body is moving with uniform velocity then F = fk
6. Work done against frictional force = fk x S = x S7. When applied force makes an angle with horizontal (pulling).Normal reaction N = mg – F sinFrictional force f = [mg - Fsin ]
Acceleration of body
Minimum pulling force required to displace the body
14. A chain of uniform length ‘L’ is placed on a rough horizontal table. The coefficient of friction between the chain and table is then the maximum fractional length of chain that can be hung freely from the edge of the table is.
Minimum fraction of length of chain that can be on the table is
15. Block on a lorry:a) The maximum acceleration of the lorry for which block beings to slide
on the floor of the lorry is
b) If a block of mass m is placed on a lorry moving with uniform acceleration a
The force acting on the block F = ma.c) If a g block does not slide and friction force on the block is f = ma.
If block slips or slides on the floor. Frictional force on the block
The acceleration (a) of the block relative to lorry is
16. Car moving on an umbanked circular road:a) When a car goes around an unbanked circular road, the static frictional
force between the wheels and the road provides the necessary centripetal
force. b) Maximum speed with which curve can be negotiated without skidding is
coefficient of static frictional between wheels and the road.c) The maximum angular velocity is
17. a) If a block having initial velocity u slides on a rough horizontal surface and
comes to rest, the acceleration of the block is
b) Distance traveled by the block before coming to rest is
Body on vertical surface.18. When a body of mass m is pressed against a vertical surface with a force P then
a) Normal reaction N =P.b) Limiting frictional force c) Frictional force between the body and surface or mg which ever is
less.d) Minimum force required to slide the body upwards.
F = mg + e) Minimum force required to prevent the body from sliding down F = mg-
19. A book of mass m is pressed between two hands by applying a horizontal force P
with each hand the book does not slide if
20. A vehicle is moving on a horizontal surface. A block of mass ‘m’ is stuck on the front part of the vehicle. The coefficient of friction between the truck and the block is The minimum acceleration with which the truck should travel, so that the body does not slide down is
[mg = ma]
Smooth inclined plane:
21. Block on a smooth inclined plane:a) N = mg cosb) Acceleration of sliding block a = g sinc) If 1 is the length of the inclined plane, h is the height and x is base. The time
taken to slide down starting from rest from the top is
e) Velocity of the block at the bottom of the inclined plane is same as the speed attained if block falls freely from the top of the inclined plane.
f) If a block is projected up the plane with a velocity u, the acceleration of the block is
g) Distance traveled up the plane before its velocity becomes zero is
h) Time of ascent is
i) Horizontal force required to prevent the body from sliding down F = mgtan .j) The minimum acceleration of the inclined plane so that a body placed on it does not
slide down is given by a = gtan .Rough inclined plane:
22. A body of mass m is placed on a rough inclined plane of inclination . If is angle
of repose. N = mgcos .
d) If the body is sliding down with uniform velocity then
23. If the block slide down from the top of the inclined plane. Velocity at the bottom of the plane is
24. In the above case time of descent is
25. The time taken by a body to slide down on a rough inclined plane is ‘n’ times the time taken by it to slide down on a smooth inclined plane of same inclination and length, then coefficient of friction is
26. If a block is projected up a rough inclined plane, the acceleration of the block is
27. a) The distance traveled by the block up the plane before the velocity becomes
zero is
b) The time of ascent is
c) If the body slides down with uniform velocity on the same plane, then
28. In the above case if time of decent is n times the time of ascent, then
29. a) Force needed to be applied parallel to the plane to move the block up with
g) Angle with vertical at which the tension h) Tension in the string at an angular displacement with vertical is
14. Safe speed of a car going on a convex bridge to travel in contact with the bridge
is
15. A ball of mass ‘m’ is allowed to slide down from rest, from the top of a incline of height ‘h’. For the ball to loop in a loop of radius ‘r’
a) Minimum height of incline h = 5r/2.b) ‘h’ is independent of mass of the ball.
16. A ball of mass ‘M’ is suspended vertically by a string of length ‘l’. A bullet of mass ‘m’ is fired horizontally with a velocity ‘u’ on to the ball sticks to it. For the system to complete the vertical circle, the minimum value of ‘u’ is given by
17. If the bob of the simple pendulum is given an initial displacement then
a) Velocity at the lowest position
b) Tension at the lowest position 18. A body is placed on the top of a hemispherical bowl and it is given a
horizontal velocity v then a) Thrust on the bowl when the radius vector turns through an angle
The body looser contact at
b) If v = 0 then N = mg [2 – 3 cos ]. The body looser contact at
Also w = 2 n (if n is r.p.s)W= 2 n/60 (if n is in rpm).
20. Torque
21. Work done w =22. Power P = 23. KE = ½ Iw2.
24. Work done
25. If a body of mass m is revolving in a circular path of radius r, with a velocity v then angular momentum of the body about origin is
L = mvr = mr2 w = Iw where I = mr2
26. A body of mass m is moving with a velocity v along a straight line p represented by ax + by + c = 0 then the angular momentum of the body about origin
27. Angular momentum of a projectile about point of projection when it is at its highest point.
28.
29. Moment of inertial
Parallel axes theorem
Perpendicular axes theorem30. For a uniform circular ring.
33. Rolling of a body without slipping on a horizontal surface.a) The body possesses both transnational and rotational kinetic energy.b) Total energy of the body
Transalational KE of the body.
c) Fraction of energy associated with translation motion
d) Fraction of energy associated with rotational motion
34. Rolling of a body down an incline without slipping.a) Acceleration of the body
b) Velocity acquired by body on reaching the bottom
h - height of the incline.c) Time taken to reach the bottom
35. When a body rolls down without sliding on an inclined plane with an inclination and height ‘h’.
M – I: Kepler’s Laws: 1. If T is the time period of plant and R is average distance of the planet from Sun Then
2. If v1 is the velocity of the planet when its distance from Sun is d, and v2 is the velocity when the distance is d2 then according to law of conservation of angular momentum.
M – II: Newton’s Law of gravitation:3. Gravitational force between two bodies of manes m1 and m2 separated by
distance
d is given by.
4. When two similar spheres each of radius r are in contact then the gravitation force between then F
5. Gravitational force acting on a body of mass m placed at a distance x distance x
from the centre (x < R) is given by
M – III: Relation between g and G:
6. Density of earth
M – IV: Variation of g with height:7. Acceleration due to gravity at a height h above the surface of the earth is
given By
a)
b) Percentage change in weight of a body or (% change in g value).
8. Acceleration due to gravity at a depth d below the surface of the earth is given by
Percentage change in weight of a body
M – VI: Variation of g with latitude:
9. a) Acceleration due to gravity at a latitude is given by W angular velocity of earth.At equator So due to rotation of the earth the value of g at equator decreases
by Rw2 = 0.034 ms-2. If earth stops rotating the value of g at equator increase by Rw2.
At poles So at poles rotation rotation of earth does not have any effect on g
value.b) If the weight of a body at equator becomes zero then
16. If the simple pendulum is in a cart moving horizontally with an acceleration
a then time period
If the cart is moving along a circular path of radius r with a speed v then a = v2/r
If the cart is sliding down an inclined plane, inclined at angle with the
horizontal,
17. When two simple pendulum of lengths 1 and 2 are get into vibration in the same direction at the same instant with same phase.Again they will be in same phase after he shorter pendulum has completed
n oscillations. To find the value of n,
n Ts = (n - 1) T1 and T
S = shorter; = longer18. Two pendulum of lengths l1 and l2 (l1 > l2) start vibrating from the mean
position in the same phase. They will be again in the same phase at the mean position after larger pendulum completes n oscillations and the shorter one completes (n + 1) oscillations. Then
19. Two simple pendulum of time period, T1 and T2 start vibrating from the mean position in same phase. The phase difference between them after t sec. is given by
They will be in same phase after a time
M – IV: Time period of a loaded spring:
20. Time period of a loaded spring where k = F/x.
Taking the mass of the spring m into consideration
When two wires are connected in parallel and same force is applied thena) Strain is same in both the wiresb) Ratios of the stresses = Y1/Y2
c) Total force F = F1 + F2
5. When a rubber cord is suspended vertically from a support it elongates under its own weight.
6. Breaking stress
Breaking force
Maximum possible elongation
Length of a wire required to break under its own weight
Rigidity modulus
7. Rigidity modulus
Shearing strain8. A tangential force F is applied on a cube of side a. if a is the lateral
displacement of the top face w.r.t the bottom face
Then Shear stress
Shear strain
M – II: Bulk Modulus:
9. Bulk Modulus
i) If a block of coefficient of cubical expansion V is heated through a rise in temperature of the pressure to be applied on it to prevent its expansion
where K is its bulk modulus.ii) When a rubber ball of volume V bulk modulus K is taken to a depth h in
water
decrease in volume
(d = density of material)10. When a pressure is applied on a substance its density changes. New
2. a) Force in addition to weight required to lift a thin wire of length l from liquid surface is F = 2l x T = 2Tl.b) Force required to lift a think circular plates of radius R from liquid surface is
c) Force in addition to weight required to pull a circular ring from water surface is r1 and r2 are internal and external radius.If it is a thin ring then .d) Force required to pull a think rectangular plate of length 1 and breadth b is from liquid surface is e) Force required to pull a think rectangular frame from liquid surface is
f) Force required to pull a capillary tube from water surface is 3. If a small drop of water is squeezed between two plates the force required
to separate the plates
A= Area of water lawyer. d= Thickness of water layer.4. A metallic wire of density d floats horizontal in water. The maximum radius
of the wire so that the wire may not sink, will be (surface tension of water = T).
5. A metallic wire of density d is laying horizontal on the surface of water. The maximum length of wire so that it may not sink, will be (surface tension of water = T)
7. a) Work done in forming a liquid drop of radius b) Work done in forming an air bubble of radius r is c) Work done in increasing the radius of a liquid drop from R1 to R2
d) Work done in forming of a soap film of size l x b is = 2T lbe) Work done in increasing the radius of a soap bubble from R1 to R2
8. When a big drop of radius R is split in to n identical drops each of radius r.
a) R = n1/3 r.
b) Increase in surface area
c) Work one in splitting the drop
d) If this process takes place under adiabatic conditions, the temperature
of ` the drop decreases by
9. When n identical small drops each of radius r combine to from a big drop of radius R thena) R = n1/3 r.
b) Decrease in surface area
c) Energy released in this process
d) If this process takes place under adiabatic conditions then the temperature
of the drop increases by
e) If the energy converts into KE then
10. Two drops of radii r1 and r2 combine in vacuum under isothermal conditions. Then if r is the radius of the drop formed,
11. When two bubbles of radii r1 and r2 in vacuum combine, under isothermal
conditions, the radii of the bubbles formed
A film of water is formed between two straight parallel wires each of length 1. The work done in increasing the separation between then by xm is w = 2Tlx.
M – III: Capillary rise:9. When a capillary tube of radius r is dipped in a liquid of surface tension T
and density d then height of the liquid in the capillary tube is given by
Note: in gravity free space the liquid rises to the full lengths of the capillary to be but it will not over flow.
10. When a capillary tube is dipped vertically the capillary rise is h. when it is
inclined by an angle to the vertical, capillary rise =
If is taken with horizontal capillary rise
Weight of liquid in capillary tube = force due to surface tension.11. Weight of the liquid in the capillary tube 12. A vessel has a small hole of radius r at the bottom. The maximum height
to which water can be poured inside the vessel without leakage in
13. A U tube has two vertical limbs of radii r1 and r2 when liquid is poured in to
it the difference in levels in
M – IV: Excess of pressure:
14. Excess of pressure inside a liquid drop of radius
Excess of pressure inside a soap bubble
Where
Excess of pressure inside a bubble in a liquid
If P0 is outside pressure, total pressure inside =P0 + excess pressure
15. If two bubbles of radii r1 and r2 are in contact, the radius of curvature of the
interface is
16. An air bubble of radius r is at a depth h is water.
18. A bubble of radius r1 is inside another bubble of radius r2. The radius of a single bubble whose excess pressure is equal to difference in pressure between inside of inner bubble and out side the outer bubbles is
19. A long capillary tube of radius r is filled with water and placed vertically.
The height of water column remaining the capillary tube
% change in length % change in area % change in Volume
2. Loss or gain of a pendulum clock due to a change in temperature per day is
3. If two rods of different material have equal lengths of 1 and at temperature T1 as the temperature is increased to T2 different in their final length is
4. For an anisotropic substance if are the coefficients of linear
expansion in three perpendicular directions then 5. When a bimetallic strip is heated it bends. Then the radius of curvature of
the bimetallic strip
Where d is the thickness of each strip. is change in temperature,
are coefficients of linear expansion of the two metals.
6.
7. Thermal stress developed in a rod heated, when it is prevented from expansion is called thermal stress
Force developed
8. A wire is bent in the form of a ring with a small gap of length on
heating to if the gap increase to x2 in length, then the coefficient of linear expansion of the wire material
9. If two rods of different materials have the difference between their lengths at all temperatures, then
10. The change in moment of inertia of a body due to rise in temperature
11. Metal tapes:a) Metal tape shows correct reading only at a temperature at which it is
constructed.b) A metal tape is graduated at and is used at
i) distance between the divisions decreases, thena) Observed reading L is less than actual valueb) Correction to be applied, c) Correct reading ii) It t2 < t1, distance between the divisions decreases, thena) Observed reading L is greater than actual valueb) c) Correct reading
12. Variation of density with temperature
13. A mercury barometer has a metal scale which is calibrated at 00C, the pressure as read by it at t0C is Ht. Then the pressure at 00C will be given by
is coefficient of real expansion of mercury is coefficient of linear expansion of metal
12. Difference forms of ideal gas equation.a) PV = nRTb) PV = (m/M)RTc) P = (dRT)/Mm – mass of the gas, d – density of the gas, M – molecular weight. For a given gas.
(if V and T are constant).
(if V is constant).
If T is constant
If P is constant 13. % change in T = % change P + % change in V.14. When n1 moles of a non reacting gas in the state (P1 V1 T1) is mixed with n2
moles of gas in state (P2 V2 T2), if the resultant mixture is in the state (P, V, T).
15. If two different gases of same mass occupy same volume at same pressure then M1/T1 = M2/T2 (M1, M2 are molecular weights)
18. THERMODYNAMICS
M – I: Joule’s law:1. The work done on a system (w) is directly proportional to heat produced in
the system.
2. A body of mass falls from height h and if it is potential energy converts into heat then