Topicwise - Heat and Temperature

1. Which of the following is the fastest process of heat transfer?

  1. conduction
  2. convection
  3. radiation
  4. insolation

2. The factors directly proportional to the amount of heat conducted through a metal rod are -

  1. Time of flow of Heat
  2. Area of cross section
  3. Temperature gradient
  4. All the above

3. 1 gm of ice at 0° C is mixed with 1 gm of steam at 100° C. After thermal equilibrium, the temperature of the mixture is

  1. 0° C
  2. 50° C
  3. 80° C
  4. 100° C

4. What would be the thermal resistance of an ideal conductor?

  1. Zero
  2. One
  3. Infinity
  4. Ten

5. Why does the bottom of a lake not freeze in severe winter even when the surface is all frozen?

  1. The water has large specific heat
  2. The conductivity of ice is low
  3. The water has large latent heat of fusion
  4. The temperature of the earth at the bottom of the lake is high.

6. A cooking pot is coated black because -

  1. black substances absorb more heat
  2. black substances reflect more heat
  3. black surfaces are easier to clean
  4. the material of the pot would not be damaged

7. Specific heat is -

  1. the specific temperature at which the substance is in solid state.
  2. the energy needed to increase the temperature of 1 gram of a substance by 1 degree Celsius.
  3. the amount of heat conducted in 1 minute.
  4. the heat needed to increase the temperature of 1 gallon of water by 1 degree Fahrenheit.

8. How will a metal container full of hot water in vaccum lose heat?

  1. by conduction
  2. by convection
  3. by radiation
  4. will stay hot for ever

9. A block of ice

  1. cannot radiate heat
  2. can radiate heat but cannot absorb heat
  3. can absorb heat but cannot radiate heat
  4. can radiate as well as absorb heat

10. As a solid undergoes a phase change to a liquid state, it

  1. releases heat while remaining at a constant temperature.
  2. absorbs heat while remaining at a constant temperature.
  3. releases heat as the temperature decreases.
  4. absorbs heat as the temperature increases.

11. A cup of hot tea on a metal table in a room loses heat by

  1. Conduction
  2. Convection
  3. Radiation
  4. All the above

12. Which among the following is true of a sphere, a cube and circular plate of same material and same mass heated to same temperature?

  1. Sphere cools the slowest
  2. Circular plate cools the fastest
  3. Cube cools the fastest
  4. Circular plate cools the slowest

13. At what temperature are the Celsius and Fahrenheit equal?

  1. + 40o
  2. - 40o
  3. - 0o
  4. + 100o

14. What would happen to a hole in a metal sheet when the sheet is heated?

  1. It decreases in size
  2. It increases in size
  3. No change is seen
  4. First increases and then decreases

15. Which of the following is equivalent of a calorie?

  1. the specific heat of water.
  2. the energy needed to increase the temperature of 1 gram of water 1 degree Celsius.
  3. equivalent to a little over 4 joules of mechanical work.
  4. all of the above.

16. In which of the following processes of heat transfer no medium is required?

  1. Conduction
  2. Convection
  3. Radiation
  4. All

17. In which of the following processes is heat transferred directly from molecule to molecule?

  1. conduction
  2. convection
  3. radiation
  4. all of the above

18. When a solid, liquid, or a gas changes from one physical state to another, the change is called

  1. melting
  2. enthalpy
  3. a phase change
  4. sublimation

19. The surface which radiates more heat at a given temperature is

  1. Black and Polished
  2. White and polished
  3. White and Rough
  4. Black and Rough

20. Compared to warm air, cool air can hold

  1. more water vapour
  2. less water vapour
  3. the same amount of water vapour
  4. temperature is unimportant here

21. The change of state directly from solid to gas is called

  1. evaporation
  2. sublimation
  3. condensation
  4. deposition

22. Which of the following is used for measurement of high temperatures?

  1. vapour thermometer
  2. energy meter
  3. resistance thermometer
  4. pyrometer

23. If boiling water is taken to the dark side of the moon it will

  1. immediately vaporize
  2. immediately freeze
  3. continue to boil
  4. stop boiling but remain hot

24. Which two liquids are used in the construction of minimum and maximum thermometers?

  1. mercury and water
  2. water and alcohol
  3. mercury and alcohol
  4. mercury and bromine

25. Which one among the following statements about thermal conductivity is correct?

  1. Steel > Wood > Water
  2. Steel > Water > Wood
  3. Water > Steel > Wood
  4. Water > Wood > Steel

26. A hot object loses heat to its surroundings in the form of heat radiation. The rate of loss of heat depends on the

  1. temperature of the object
  2. temperature of the surroundings
  3. temperature difference between the object and its surroundings
  4. average temperature of the object and its surroundings

27. Body A of mass 2 kg and another body B of mass 4 kg and of same material are kept in the same sunshine for some interval of time. If the rise in temperature is equal for both the bodies, then which one among the following in this regard is correct?

  1. Heat absorbed by B is double because its mass is double
  2. Heat absorbed by A is double because its mass is half
  3. Heat absorbed by Both A and B is equal because the quantity of heat absorbed does not depend upon mass
  4. Heat absorbed by B is four times than the heat absorbed by A because the quantity of heat absorbed is proportional to square of the mass

28. A glass of water does not turn into ice as it reaches 0° C. It is because

  1. water does not solidify at 0° C
  2. a certain amount of heat must be supplied to the glass of water so as to solidify
  3. a certain amount of heat must be taken out from the glass of water so as to solidify
  4. water solidifies at 0° K only

29. Thermometer A and B have ice points marked at 15° and 25° and steam points at 75° and 125° respectively. When thermometer A measures the temperature of a bath as 60° the reading of B for the same bath is

  1. 60°
  2. 75°
  3. 90°
  4. 100°

30. Which one among the following waves are called waves of heat energy?

  1. Radio waves
  2. Infrared waves
  3. Ultraviolet waves
  4. Microwaves

31. In a pressure cooker cooking is faster because the increase in vapour pressure

  1. increases the specific heat
  2. decreases the specific heat
  3. decreases the boiling point
  4. increases the boiling point

32. If a heater coil is cut into two equal parts and only one part is used in the heater, the heat generated will be:

  1. doubled
  2. four times
  3. one-fourth
  4. halved

33. The best and the poorest conductors of heat are respectively

  1. silver (Ag) and lead (Pb)
  2. copper (Cu) and aluminium (Al)
  3. silver (Ag) and gold (Au)
  4. copper (cu) and gold (Au)

34. Which one of the following is the mode of heat transfer in which warm material is transported so as to displace a cooler material?

  1. Conduction only
  2. Convection only
  3. Radiation
  4. Both conduction and convection

35. Which one among the following denotes the smallest temperature?

  1. 1° on the Celsius scale
  2. 1° on the Kelvin scale
  3. 1° on the Fahrenheit scale
  4. 1° on the Reaumur scale

36. Which among the following thermometers is preferred for measuring temperature around 1250° C?

  1. Mercury thermometer
  2. Constant volume gas thermometer
  3. Optical pyrometer
  4. Platinum resistance thermometer