# MCQs for Physics Class 11 with Answers Chapter 11 Thermal Properties of Matter

Students of class 11 Physics should refer to MCQ Questions Class 11 Physics Thermal Properties of Matter with answers provided here which is an important chapter in Class 11 Physics NCERT textbook. These MCQ for Class 11 Physics with Answers have been prepared based on the latest CBSE and NCERT syllabus and examination guidelines for Class 11 Physics. The following MCQs can help you to practice and get better marks in the upcoming class 11 Physics examination

## Chapter 11 Thermal Properties of Matter MCQ with Answers Class 11 Physics

MCQ Questions Class 11 Physics Thermal Properties of Matter provided below have been prepared by expert teachers of grade 11. These objective questions with solutions are expected to come in the upcoming Standard 11 examinations. Learn the below provided MCQ questions to get better marks in examinations.

Question. A faulty thermometer reads freezing point and boiling point of water as –5 °C and 95 °C respectively. What is the correct value of temperature as it reads 60 °C on faulty thermometer?
(a) 60 °C
(b) 65 °C
(c) 64 °C
(d) 62 °C

B

Question. Three stars A, B, C have surface temperatures TA, TB and TC. A appears bluish, B appears reddish and C appears yellowish. We can conclude that
(a) TA > TC > TB
(b) TA > TB > TC
(c) TB > TC > TA
(d) TC > TB > TA

A

Question. The plots of intensity of radiation versus wavelength of three black bodies at temperatures  T1, T2 and T3 are shown. Then,

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

D

Question. Which of the following statement does not hold good for thermal radiation?
(a) The wavelength changes when it travels from one medium to another.
(b) The frequency changes when it travels from one medium to another.
(c) The speed changes when it travels from one medium to another.
(d) They travel in straight line in a given medium.

B

Question. Which one of the following is um – T graph for perfectly black body? um is the frequency of radiation with maximum intensity and T is the absolute temperature.

(a) A
(b) B
(c) C
(d) D

C

Question. Refer to the plot of temperature versus time showing the changes in the state of ice on  heating (not to scale).
Which of the following is correct?

(a) AB represents ice and water are not in the thermal equilibrium.
(b) At B water starts boiling.
(c) At C all the water gets converted into steam.
(d) CD represents water and steam in equilibrium at boiling point.

D

Question. If the temperature of hot black body is raised by 5%, rate of heat energy radiated would be increased by how much percentage?
(a) 12%
(b) 22%
(c) 32%
(d) 42%

B

Question. The coefficient of expansion of a crystal in one direction (x-axis) is 2.0 × 10–6 K–1 and that in the other two perpendicular (y-and z-axes) direction is 1.6 ×× 10–6 K–1. What is the coefficient of cubical expansion of the crystal?
(a) 1.6 × 10–6 K–1
(b) 1.8 × 10–6 K–1
(c) 2.0 × 10–6 K–1
(d) 5.2 × 10–6 K–1

D

Question. In the phase diagram shown, the point Q corresponds to the triple point of water. The regions I, II and III respectively correspond to phases

(a) liquid, solid, vapour
(b) solid, liquid, vapour
(c) liquid, vapour, solid
(d) solid, vapour, liquid

A

Question. A body A of mass 0.5 kg and specific heat 0.85 J g–1 K–1 is at a temperature of 60°C. Another body B of mass 0.3 kg and specific heat 0.9 J g–1 K–1 is at a temperature of 90°C. When they are connected through a conducting rod, heat will flow from
(a) A to B
(b) B to A
(c) heat can’t flow
(d) first from A to B, then B to A

B

Assertion & Reasoning Based MCQs :

Question. Assertion (A) : A body with large reflectivity is a poor emitter.
Reason (R) : Poor absorbers of heat are poor emitters.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

A

Question. Assertion (A) : In the upper part of the atmosphere the temperature of air is of the order of 1000 K, even then it is quite cold there.
Reason (R) : The heat density of upper atmosphere is very high.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

C

Question. Assertion (A) : When a solid iron ball is heated, percentage increase is its volume is largest.
Reason (R) : Coefficient of superficial expansion is twice that of linear expansion where as coefficient of volume expansion is three time of linear expansion.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

A

Question. Assertion (A) : The density of water is maximum at 4° C.
Reason (R) : The volume of water decreases while heating from 0°C to 4°C.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

B

Question. Assertion (A) : The coefficient of volume expansion has dimension K–1.
Reason (R) : The coefficient of volume expansion is defined the change in volume per unit volume per unit change in temperature.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

A

Question. Assertion (A) : For a perfectly black body, absorption coefficient and emission coefficient is  one.
Reason (R) : Perfect absorbers are perfect emitters.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

A

Question. Assertion (A) : Greater is the coefficient of thermal conductivity of a material, smaller is the thermal resistance of a rod of that material.
Reason (R) : Thermal resistance is the ratio of temperature difference between the ends of the conductor and rate of flow of heat.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

B

Question. Assertion (A) : A beaker is completely filled with water at 4°C. It will overflow, both when heated or cooled.
Reason (R) : There is expansion of water below and above 4°C.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

A

Question. Assertion (A) : Thermal conductivity depends on nature of material of the wall.
Reason (R) : When temperature difference across the two sides of a wall is increased, its thermal conductivity increases.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

C

Question. Assertion (A) : Snow is better insulator than ice.
Reason (R) : Snow contains air packet and air is good insulator of heat.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false

A

Case Based MCQs :

Specific Heat Capacity
Heat capacity of a substance is defined as H = ΔQ/ΔT = ms , where ΔQ is amount of head supplied to the substance to change its temperature from T to T + ΔT.
Specific heat capacity is the amount of heat per unit mass absorbed or given off to change its temperature by one unit. S = 1/m ΔQ/ΔT = H/m
It depends on the nature of substance and its temperature.

Question. Calorie is defined as the amount of heat required to raise the temperature of 1 g of water by 1°C and it is defined under which of the following conditions?
(a) From 14.5°C to 15.5°C at 760 mm of Hg
(b) From 98.5°C to 99.5°C at 760 mm of Hg
(c) From 13.5°C to 14.5°C at 76 mm of Hg
(d) From 3.5°C to 4.5°C at 76 mm of Hg

A

Question. Heat capacity of a substance is infinite. It means
(a) heat is given out.
(b) heat is taken in.
(c) no change in temperature whether heat is taken in or given out.
(d) all of these.

C

Question. Find the thermal capacity of 40 g of aluminum.
(s = 0.2 cal/g K)
(a) 168 J/°C
(b) 672 J/°C
(c) 840 J/°C
(d) 33.6 J/°C

D

Question. Which one of the following substances has highest specific heat capacity at room  temperature and atmospheric pressure?
(a) Water
(b) Ice
(c) Aluminium
(d) Mercury

A

Question. Water is used as a coolant because
(a) it has lower density.
(b) it has low specific heat.
(c) it has high specific heat.
(d) it is easily available.

C

The increase in the dimensions of a body due to the increase in its temperature is called thermal expansion. Thermal expansion is present in solids, liquids and gases. In the case of solids, the increase will be in length, area and volume. In liquids and gases, only expansion in volume is possible as they do not possess any fixed shape. In the case of gases, the state of a gas at any instant is dependent on its volume, pressure and temperature. Hence a gas can be heated at constant volume or at constant pressure. The property of thermal expansion of substance is different for different substances and it also depends on the state of the substance viz, solid, liquid or gas.
Relation between α, β and γ
The three coefficients of thermal expansion are related as α =β/2 = γ/3.

Question. There is a hole in the middle of a copper plate. When heating the plate, diameter of hole  would
(a) always increase
(b) always decrease
(c) remains the same
(d) none of these

A

Question. If a, b and g are coefficients of linear, superficial and volume expansion respectively, then

B

Question. Which of the following graphs correctly shows variation of coefficient of volume expansion of copper as a function of temperature?

C

Question. The coefficient of volume expansion of liquid is γ. The fractional change in its density for ΔT rise in temperature is
(a) γΔT
(b) ΔT/γ
(c) 1 + γΔT
(d) 1 – γΔT

A

Question. Two spheres A and B are made of the same material and have the same radius. Sphere A is hollow and sphere B is solid. Both the spheres are heated to the same temperature. Which of the following is correct?
(a) A expands more than B.
(b) A expands less than B.
(c) Both the spheres expand equally.
(d) Data is insufficient.