1. The SI unit of heat is:
A) Calorie
B) Joule
C) Watt
D) Kelvin
Answer: B) Joule
2. Temperature is a measure of:
A) Total heat energy
B) Average kinetic energy of molecules
C) Total potential energy
D) Heat capacity
Answer: B) Average kinetic energy of molecules
3. Instrument used to measure temperature is:
A) Barometer
B) Thermometer
C) Calorimeter
D) Hygrometer
Answer: B) Thermometer
4. Heat transfer by direct contact is called:
A) Radiation
B) Convection
C) Conduction
D) Insulation
Answer: C) Conduction
5. Heat transfer in liquids and gases mainly occurs by:
A) Conduction
B) Radiation
C) Convection
D) Reflection
Answer: C) Convection
6. The temperature scale having the lowest possible temperature is:
A) Celsius
B) Fahrenheit
C) Kelvin
D) Rankine
Answer: C) Kelvin
7. Absolute zero on Kelvin scale is:
A) 0°C
B) -100°C
C) -273°C
D) -32°C
Answer: C) -273°C
8. Metals are good conductors of heat because they have:
A) High density
B) Free electrons
C) High melting point
D) High color intensity
Answer: B) Free electrons
9. Which material is a good insulator of heat?
A) Copper
B) Aluminum
C) Glass
D) Silver
Answer: C) Glass
10. The transfer of heat without a medium is called:
A) Conduction
B) Convection
C) Radiation
D) Diffusion
Answer: C) Radiation
11. Heat always flows from:
A) Cold to hot body
B) Hot to cold body
C) Solid to liquid
D) Liquid to gas
Answer: B) Hot to cold body
12. The unit of temperature on Celsius scale is:
A) °F
B) K
C) °C
D) J
Answer: C) °C
13. A clinical thermometer is used to measure:
A) Room temperature
B) Boiling point
C) Human body temperature
D) Freezing point
Answer: C) Human body temperature
14. The normal human body temperature is:
A) 35°C
B) 36°C
C) 37°C
D) 38°C
Answer: C) 37°C
15. The boiling point of water at sea level is:
A) 90°C
B) 95°C
C) 100°C
D) 110°C
Answer: C) 100°C
16. The freezing point of water is:
A) 0°C
B) 10°C
C) 32°C
D) 100°C
Answer: A) 0°C
17. A calorimeter is used to measure:
A) Temperature
B) Heat energy
C) Pressure
D) Density
Answer: B) Heat energy
18. Dark-colored objects absorb heat:
A) Less
B) More
C) Same as white
D) Not at all
Answer: B) More
19. Light-colored objects:
A) Absorb more heat
B) Reflect more heat
C) Produce heat
D) Store heat
Answer: B) Reflect more heat
20. The process of heat transfer from Sun to Earth is by:
A) Conduction
B) Convection
C) Radiation
D) Evaporation
Answer: C) Radiation
21. Expansion of solids on heating is generally:
A) Very large
B) Moderate
C) Very small
D) Unlimited
Answer: C) Very small
22. Liquids expand on heating more than:
A) Gases
B) Solids
C) Plasma
D) Vacuum
Answer: B) Solids
23. Gases expand on heating:
A) Least
B) Moderately
C) Most
D) Not at all
Answer: C) Most
24. Heat required to change solid into liquid is called:
A) Sensible heat
B) Latent heat of fusion
C) Latent heat of vaporization
D) Specific heat
Answer: B) Latent heat of fusion
25. Heat required to change liquid into gas is called:
A) Latent heat of fusion
B) Specific heat
C) Latent heat of vaporization
D) Thermal heat
Answer: C) Latent heat of vaporization
26. The amount of heat required to raise temperature of unit mass by 1°C is called:
A) Heat capacity
B) Latent heat
C) Specific heat capacity
D) Thermal conductivity
Answer: C) Specific heat capacity
27. Water has high specific heat, so it:
A) Heats quickly
B) Cools quickly
C) Changes temperature slowly
D) Boils fast
Answer: C) Changes temperature slowly
28. Mercury is used in thermometers because it:
A) Is cheap
B) Is colorful
C) Expands uniformly
D) Freezes easily
Answer: C) Expands uniformly
29. The degree of hotness or coldness of a body is called:
A) Heat
B) Energy
C) Temperature
D) Pressure
Answer: C) Temperature
30. The rate of heat flow depends on:
A) Color only
B) Mass only
C) Temperature difference
D) Shape only
Answer: C)