9th class Physics, Chapter 7: Thermal Properties of Matter MCQs

1. How do the molecules in a solid behave?

1. (A) Move randomly
2. (B) Vibrate about their mean positions ✓
3. (C) Rotate and vibrate randomly at their own positions
4. (D) Move in a straight line from hot to cold ends.

2. What type of motion is of the molecules in a gas?

1. (A) Linear motion
2. (B) Random motion ✓
3. (C) Vibratory motion
4. (D) Rotatory motion

3. Temperature of a substance is:

1. (A) the total amount of heat contained in it
2. (B) the total number of molecules in it
3. (C) degree of hotness or coldness ✓
4. (D) dependent upon the intermolecular distance

4. Heat is the:

1. (A) total kinetic energy of the molecules
2. (B) the internal energy
3. (C) work done by the molecules
4. (D) the energy in transit ✓

5. In Kelvin scale, the temperature corresponding to melting point of ice is:

1. (A) zero
2. (B) 32
3. (C) -273
4. (D) +273 ✓

6. The temperature which has the same value on Celsius and Fahrenheit scale is:

1. (A) -40 ✓
2. (B) +40
3. (C) +45
4. (D) -45

7. Which one is a better choice for a liquid-in-glass thermometer?

1. (A) Is colourless
2. (B) Is a bad conductor
3. (C) Expand linearly ✓
4. (D) Wets glass

8. One disadvantage of using alcohol in a liquid-in-glass thermometer:

1. (A) it has large expansivity
2. (B) it has low freezing point (-112 °C)
3. (C) it wets the glass tube ✓
4. (D) its expansion is linear

9. Water is not used as a thermometric liquid mainly due to:

1. (A) colourless
2. (B) a bad conductor of heat
3. (C) non-linear expansion ✓
4. (D) a low boiling point (100 °C)

10. A thermometer has a narrow capillary tube so that it:

1. (A) quickly responds to temperature changes
2. (B) can read the maximum temperature
3. (C) gives a large change for a given temperature rise ✓
4. (D) can measure a large range of temperature

11. Which thermometer is most suitable for recording rapidly varying temperature?

1. (A) Thermocouple thermometer ✓
2. (B) Mercury-in-glass laboratory thermometer
3. (C) Alcohol-in-glass thermometer
4. (D) Mercury-in-glass clinical thermometer

12. According to kinetic molecular theory, matter is composed of very small particles called:

1. (A) cells
2. (B) crystals
3. (C) planets
4. (D) molecules ✓

13. The force of attraction between molecules is called the:

1. (A) gravitational force
2. (B) magnetic force
3. (C) frictional force
4. (D) intermolecular force ✓

14. The intermolecular force decreases with the:

1. (A) decrease of distance between the molecules
2. (B) increase of temperature only
3. (C) decrease of mass
4. (D) increase of distance between the molecules ✓

15. The molecules of a substance possess kinetic energy due to their:

1. (A) colour
2. (B) size
3. (C) motion ✓
4. (D) position

16. The molecules of a substance possess potential energy due to the:

1. (A) mass of the vessel
2. (B) force of attraction between them ✓
3. (C) speed of the molecules
4. (D) colour of the substance

17. The temperature of a substance depends upon the average of the molecules':

1. (A) volume
2. (B) kinetic energy ✓
3. (C) potential energy
4. (D) mass

18. A liquid has:

1. (A) neither a definite shape nor volume
2. (B) a definite volume but no definite shape ✓
3. (C) a definite shape but no definite volume
4. (D) both a definite shape and volume

19. A gas has:

1. (A) a definite shape only
2. (B) a definite volume only
3. (C) both a definite shape and volume
4. (D) neither a definite shape nor a definite volume ✓

20. A solid has a definite shape and volume because its molecules:

1. (A) are far apart
2. (B) move randomly in all directions
3. (C) are held at fixed positions by strong forces ✓
4. (D) slide over each other