# Thermal Properties of Matter VBQs Class 11 Physics

VBQs Thermal Properties of Matter Class 11 Physics with solutions has been provided below for standard students. We have provided chapter wise VBQ for Class 11 Physics with solutions. The following Thermal Properties of Matter Class 11 Physics value based questions with answers will come in your exams. Students should understand the concepts and learn the solved cased based VBQs provided below. This will help you to get better marks in class 11 examinations.

## Thermal Properties of Matter VBQs Class 11 Physics

Question. How much amount of energy must be given to a mixture of 10 g hydrogen and 20 g of He to change the temperature by 30°C, while they are kept in a closed vessel?
(a) 500 R
(b) 600 R
(c) 300 R
(d) 400 R

B

Question. The following graph shows power of a black body radiation vs temperature at three temperatures. Then

(a) T1 > T2 > T3
(b) T3 > T2 > T1
(c) T1 = T2 = T3
(d) T2 > T1 > T3

A

Question. The shown rod is in steady state with T1 > T4 then which of the following statement is true

(a) Heat is flowing from T4 to T1
(b) T2, T3 are are increasing with time
(c) T2, T3 are constant with time
(d) T3 = T2

C

Question. When a room is heated upto a temperature 30°C,the outside temperature is –30°C and when it is heated upto 20°C, outside temperature is –60°C.
Then the temperature of heater used to heat the room is (Newton’s law of cooling is valid)(Assume same time duration of heating)
(a) 20°C
(b) 40°C
(c) 80°C
(d) 60°C

D

Question. A bullet having velocity V, collides against a wall and one-third of its kinetic energy is converted into heat.
If specific heat of bullet is S, then the temperature of the bullet rises by (Given, J=mechanical equivalent of heat)
(a) V2j /6s
(b) V2/6 jS
(c) V2/6 jS
(d) V2/3S

C

Question. Which of the following curve shows the behaviour of density of water with temperature accurately?

B

Question. A bimetallic strip is made of two metals M1 and M2 having coefficient of linear expansion α1 and α2, respectively (α1 > α2). When the strip is heated then shape of strip will be

D

Question. A calorimeter ‘A’ contains 100 g water at 50ºC and another calorimeter ‘B’ contains 150 g water at 20ºC.
If the water of both the calorimeters is mixed together, the temperature of the mixture will be
(a) 70ºC
(b) 35ºC
(c) 32.0ºC
(d) 15.0ºC

C

Question. Two identical cubes of metals are connected as shown in figure A. 50 cal heat flows through it in 2 minute. If the cubes are connected as figure B, then the same amount of heat will flow through the rods in

(a) 0.5 minute
(b) 1 minute
(c) 2 minute
(d) 8 minute

A

Question. A liquid kept in an open vessel cools according to Newton’s law of cooling. The temperature of the liquid (θ) is plotted with time (t). Which of the following graphs  correctly shows the variation of θ with t?

A

Question. A black body having temperature T K emits energy at the rate of E watt per minute. If the temperature is reduced to T/2 K , then rate of emission becomes
(a) 1/16 E
(b) 1/32 E
(c) 16 E
(d) 32 E

A

Question. Two rods having length l1 and l2 made by two material having thermal expansion coefficient α1 and α2. If the difference between their lengths is independent of temperature, then
(a) l1α1 = l2α2
(b) l1α2 = l2α1
(c) l12α1 = l12α2
(d) l2 + l1 = α2 + α1

A

Question. The heat energy is supplied to a 100 g solid with a rate of 200 cal/minute. The temperature (θ) versus time (t) plot is shown below. The latent heat of fusion of the substance is

(a) 30 cal/g
(b) 20 cal/g
(c) 10 cal/g
(d) 5 cal/g

A

Question. The three rods of identical dimensions and made of different materials are joined as shown in the diagram below. The temperatures of the ends A, B, C are given in the diagram itself. Which of the following is incorrect statement?

(a) The temperature at the junction O is 50ºC
(b) The heat current in the rod AO is from A to O
(c) The heat current in the rod BO is from O to B
(d) The heat current in the rod OC is from O to C

D

Question. Two spheres of radius r and R at temperature 1000 K and 1500 K respectively radiates energy at same rate then
(a) 16r2 = 81R2
(b) 16R2 = 81r2
(c) 2R2 = 3r2
(d) 3R2 = 2r2

D

Question. A steel meter scale is to be ruled so that the millimeter intervals are accurate upto 1 × 10–3 mm at certain temperature. The maximum temperature variation allowed during ruling is (α = 1 × 10–4/K)
(a) 5°C
(b) 2°C
(c) 10°C
(d) 4°C

C

Question. The mass of the cube of an unknown metal is 5 kg.
When 15,000 J of heat energy is supplied to it, its temperature rises by 3ºC. The heat capacity of the cube is
(a) 5000 J/ºC
(b) 1000 J/ºC
(c) 3000 J/ºC
(d) 3 J/ºC

A

Question. Ice starts forming on the surface of lake and takes 8 hours to form a layer of 1 cm thick. To increase the thickness of layer to 2 cm, it will take (assume water is at 0°C)
(a) 8 hours
(b) < 8 hours
(c) < 16 hours
(d) > 16 hours

D

Question. A rod of length L and cross sectional area A is subjected to a temperature difference ΔT at two ends and the rate of heat flow is Q. If the rod is cut in two pieces from the middle lengthwise and now the two rods are connected in series and subjected to same temper ature difference. Then new rate of heat flow is
(a) 4Q
(b) Q/4
(c) 2Q
(d) Q/2

B

Question. Which of the following graph correctly shows, the behaviour of volume of water (V) with temperature (T)?

D

Question. J is mechanical equivalent of heat, R is radius of earth, ω is angular velocity of earth and S is specific heat of earth. If earth suddenly stop the rotation about it’s polar axis, then the maximum change in temperature of earth will be
(a) Rω/5SJ
(b) R2ω2/5SJ
(c) 1/3 R2ω2/SJ
(d) Rω/3SJ

B

Question. A body cools in 10 minutes from 60oC to 40oC.
What will be its temperature after next 10 minutes, if surrounding temperature is 10oC (Assume Newton’s law of cooling valid)
(a) 29 oC
(b) 50 oC
(c) 28 oC
(d) 35 oC

C

Question. Temperature of water in a lake is at 0ºC and atmospheric temperature is –10ºC. If 1 cm thickness of ice formed on the lake takes 2 days, then time taken to form next 2 cm thickness of ice is
(a) 8 days
(b) 6 days
(c) 16 days
(d) 10 days

C

Question. A black-body has maximum wavelength λm at 2500 K. Corresponding wavelength at 4000 K will be
(a) 16/81 λm
(b) 3/2 λm
(c) 2/3 λm
(d) 5/8 λm

B

Question. The thermal conductivity of the combination of slabs

(a) K1 + K2
(b) (2K1K2) / (K1 + K2)
(c) K1K2
(d) (K1 + K2)/(2K1K2)

B

Question. Two rods of length l and 2l, thermal conductivities 2k and k are connected end to end. If cross-sectional area of the rods are equal, then equivalent thermal conductivity of the system is
(a) (5/6)K
(b) 1.5k
(c) 1.2k
(d) (8/9)K

C

Question. The temperature of spherical black body falls from 80ºC to 76ºC in 10 minutes and from 76ºC to 74ºC in next 10 minutes. Assuming that the body follows Newton’s law of cooling, the temperature of surroundings is
(a) 72ºC
(b) 74ºC
(c) 70ºC
(d) 65ºC

A

Question. A liquid of mass m and specific heat c is heated to a temperature θ. The temperature of another liquid of mass 2m and specific heat 2c is at temperature θ/2 . If the two liquids are mixed, the temperature of the mixture will be
(a) (5/3)θ
(b) (3/5)θ
(c) θ
(d) θ/2