Thermodynamics Mock Test – Class 11 Physics

1. The SI unit of the gas constant in is obtained as

2. A smooth - curve is normally drawn for a quasistatic process because

3. The differential form of the first law for a small thermodynamic change is commonly written as

4. A heat reservoir is best described as a body that

5. A working gas in a cycle absorbs on one part, rejects on another part, and has of work done on it during a compression step. The net work delivered by the gas over the whole cycle is

6. Consider the following statements about heat capacities.
I. is specific heat capacity.
II. is molar heat capacity.
III. The unit of is .

7. A student records the state of a fixed amount of gas as , , and . Which entry in the record is not a state variable for the gas state?

8. A Carnot refrigerator operates between a cold reservoir at and a hot reservoir at , where . Its coefficient of performance is

9. In a quasistatic expansion of a gas, the small work done by the gas is written as

10. A graph is described below.

As increases, the graph shows that

11. A fixed ideal gas is heated at constant volume until its pressure changes from to . If its initial temperature is , the final temperature is

12. A heat engine and a refrigerator are compared in terms of useful output. The correct pairing is

13. A Carnot engine and a Carnot refrigerator operate between the same reservoirs at and . The engine efficiency and refrigerator COP are respectively

14. The quantity has no unit because

15. A thermometer is first placed in a beaker of water and later in an oil bath. In both cases, the final steady reading is . What would happen if the water and oil were brought into thermal contact under these conditions?

16. Assertion: For gases, is greater than .
Reason: At constant pressure, part of the supplied heat is used in expansion work, but at constant volume no pressure-volume work is done.

17. A heat engine has in each cycle. Its efficiency is

18. Assertion: Internal energy is a state function.
Reason: The change in internal energy between two equilibrium states depends only on those states, not on the path joining them.

19. A Carnot refrigerator works between and . It removes of heat from the cold reservoir. The heat rejected to the hot reservoir is

20. A gas is taken through the following two-step process: Step P is isochoric heating from to , and Step Q is isothermal expansion at . For the whole two-step process, the internal-energy change of the ideal gas is determined by

21. A thermodynamic description becomes unreliable if a gas has no well-defined pressure or temperature throughout the chosen system. The main reason is that

22. A fixed amount of gas is enclosed in a cylinder fitted with a movable piston. For the gas as the system, the piston and outside air are part of the

23. A sealed piston-cylinder contains of gas. During heating, of energy enters as heat and the gas does of work on the piston, but no gas escapes. How should this system be classified, and what kind of transfers occur?

24. A reversible heat pump works between a cold outside region at and a warm room at . If it consumes of work, the heat delivered to the room is

25. Read the situation below and answer the question.

The total heat supplied in the two steps is closest to

26. For an ideal gas, and . The value of inferred from Mayer’s relation is closest to

27. A heat engine operating between and rejects of heat per cycle. If it were Carnot, the heat absorbed would be

28. A heat pump supplies heat to a warm room by taking heat from a cold outside region and using work . Its coefficient of performance as a heat pump is

29. For a fixed amount of ideal gas heated at constant pressure from to , its volume

30. In a constant-pressure heating process for an ideal gas, the heat supplied is , while the internal-energy change is . The expansion work is therefore

31. In a closed thermodynamic system,

32. A Carnot engine works between and . If a real engine between the same reservoirs claims efficiency, the claim is

33. A proposed cyclic heat engine receives from a hot reservoir, rejects no heat, and delivers of work. The proposal

34. A Carnot engine is required to have efficiency while operating with a hot reservoir at . The cold reservoir temperature must be

35. A claim says, “If the volume of an ideal gas changes, its internal energy must change.” The best response is:

36. An isothermal process is a process in which

37. A ideal gas with is taken from to at constant pressure and then cooled at constant volume back to . Taking , the net heat supplied in the two steps is

38. A process at constant volume is called

39. A claim says, “A Carnot engine between and can be made efficient if friction is completely removed.” The best response is:

40. A symbolic derivation uses and . The expression for in terms of and is

41. A gas in a container has molecules moving randomly at high speeds, yet a pressure gauge attached to the container shows one steady reading. This situation illustrates that

42. Friction makes a mechanical thermodynamic process irreversible because it

43. A refrigerator has coefficient of performance and rejects of heat to the room in each cycle. The heat removed from the cold chamber is

44. Free expansion of an ideal gas into vacuum in an insulated container has which idealized energy result?

45. A metal block at is placed in contact with another block at . Before thermal equilibrium is reached, heat transfer is mainly from

46. A small thermometer is put first in liquid P and later in liquid Q. The thermometer gives the same steady reading in both liquids. The best inference is that

47. A gas goes from state to state along Path 1 and then along Path 2 in a separate trial. The two paths have different areas under their - curves but the endpoints are the same. The quantity that must be the same in both trials is

48. The ratio of specific heats for a gas is defined as

49. A - graph is described below.

The described curve is best identified as

50. A fixed amount of ideal gas is taken from state P to state Q along two different paths. Path 1 is isochoric heating followed by isobaric expansion. Path 2 is isothermal expansion followed by isochoric heating. If both paths end at the same final temperature, the quantity that must be identical for the two paths is