Thermodynamics Mock Test – Class 11 Physics

1. An isothermal process is a process in which

2. A table lists quantities associated with a gas. Identify the row in which both entries are state variables.

3. A ideal gas is heated at constant pressure by . If and , what heat is supplied?

4. A reversible adiabatic compression of an ideal gas reduces its volume to one-half of the initial volume. If , the pressure change is best described by

5. Assertion: Thermodynamics can describe an equilibrium gas sample without specifying the velocity of each molecule.
Reason: Macroscopic variables such as , , and can characterize the bulk state of the gas.

6. A fixed mass of gas has density , mass , and volume . Its density is written as . If the gas reaches the same final state through two paths, the final density is

7. A steam turbine has steam entering through one pipe and leaving through another while doing work on the blades. For the steam-flow region as the system, this is mainly an example of

8. A Carnot engine operates between and . A Carnot refrigerator operates between the same two reservoirs. The refrigerator COP and engine efficiency are respectively

9. A process record says: , , and the gas is ideal with . The temperature change of the gas is

10. A cyclic engine absorbs from a source and rejects to a sink, where and are positive magnitudes. The work output is

11. 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

12. A table compares two ideal-gas processes. Identify the row that is fully consistent.

13. Use the arrangement described below: a gas is inside a cylinder with a movable, frictionless piston. The cylinder wall is conducting, and the piston can move outward when the gas is heated. If the gas alone is the system, what can cross or act through the boundary?

14. 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

15. A statement says, “The heat of a gas at a state is .” The main problem with this statement is that

16. Read the situation below and answer the question.

Which formula-use decision is safest for the free-expansion step itself?

17. A fixed ideal gas has the same initial and final temperatures in two processes. Process P is isothermal expansion. Process Q is free expansion in an insulated rigid container. The correct comparison is

18. A gas initially has a pressure difference between two regions inside the same container. After some time, the pressure becomes uniform and there is no bulk motion. This change mainly shows approach toward

19. A claim says, “Since heat changes the temperature of a gas, heat must be a state variable like .” The best correction is:

20. A thermodynamics solution uses with and , giving . The correct conclusion is

21. A Carnot refrigerator removes of heat from the cold reservoir and has coefficient of performance . The required work input is

22. A fixed ideal gas first expands isothermally from to at temperature , then is compressed isobarically back to volume . The statement that is certainly true is

23. 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

24. A lab record gives the following for an ideal gas:

Starting from pressure , the final pressure after both steps is

25. Read the situation below and answer the question.

The work done by the gas and the heat supplied are respectively

26. A hot metal spoon is placed in colder water. The energy transfer from the spoon to the water takes place mainly because of

27. A reversible adiabatic expansion of an ideal gas changes the pressure from to . If , the ratio of final to initial temperature is

28. A statement says, “The gas has absorbed heat, so its internal energy must have increased by exactly the same amount.” The statement is not always valid because

29. The first law of thermodynamics can account for energy conservation in a process, but it does not by itself decide

30. A gas expands freely into an evacuated half of a rigid insulated vessel. Why is a regular - work-area calculation not suitable during the expansion?

31. A reversible adiabatic expansion of an ideal gas causes its volume to increase. According to , the pressure

32. Use the graph description below.

The slope of this graph is

33. The table compares two basic thermodynamic devices.

The entries P and Q are respectively

34. A triangular - cycle has vertices , , and . The cycle is traversed . The net heat supplied in one cycle is

35. A thermodynamic state variable is a quantity that

36. A thermodynamic process is reversible only if both the system and surroundings can be restored to their initial states. Which situation most clearly prevents this?

37. A heat engine absorbs from a hot reservoir at . It rejects to a cold reservoir at . The correct judgement is

38. The efficiency of a Carnot engine operating between hot reservoir temperature and cold reservoir temperature is

39. For a reversible refrigerator, reducing the temperature gap while keeping the cold reservoir temperature nearly fixed makes the coefficient of performance

40. A gas is heated at constant pressure, and its temperature rises. The relation for gases is mainly because

41. A closed system receives of heat. Its internal energy increases by . What work is done by the system?

42. Heat in thermodynamics is best described as

43. Study the table and identify the row in which both classifications are correct.

44. A thermodynamic path is drawn as a vertical line upward on a - graph. For a fixed ideal gas, the process represented is

45. A claim says, “If heat is supplied to a gas, its internal energy must increase.” The best correction is:

46. A sealed gas is taken from state P to state Q by two different processes. In one process, of heat enters the gas; in another, of heat enters it. What does this show about heat ?

47. A gas is compressed inside a thermally insulated cylinder. If of work is done on the gas, the change in internal energy is

48. In the symbol , the subscript indicates that the molar heat capacity is measured at

49. Assertion: For a gas, is usually greater than .
Reason: For gases, because constant-pressure heating includes expansion work.

50. A vertical line on a - graph represents an isochoric process because