Class 11 Physics — Chapter 12: Thermodynamics Online Test

1. The relation is called:

2. Maxwell’s relation expresses relationship between:

3. The entropy change of surroundings during a reversible adiabatic process is:

4. Why can no real engine achieve Carnot efficiency?

5. A heat engine absorbs 2000 J of heat at 500 K and rejects 1500 J at 300 K. Does it violate the Second Law?

6. If a refrigerator has a COP of 4, what does it mean?

7. The Brayton cycle is used in:

8. The constant in Van der Waals equation accounts for:

9. A 100 g piece of steam at is passed into 500 g of water at . Find the final temperature when equilibrium is reached. (Latent heat of vaporization = , ).

10. A heat engine absorbs from a source at and rejects to the sink. Find its efficiency.

11. A system absorbs of heat and performs of work. Which statement is correct?

12. Which law of thermodynamics introduces the concept of temperature?

13. Which law of thermodynamics sets the ultimate limit for the efficiency of heat engines?

14. Why is the Zeroth Law significant in thermodynamics?

15. Convert into Kelvin.

16. A system does of work on surroundings and its internal energy decreases by . How much heat was supplied?

17. If a system absorbs of heat and its internal energy increases by , how much work has the system done?

18. Two bodies with masses and , specific heats and , and initial temperatures and , are brought in thermal contact. The final equilibrium temperature is given by:

19. A resistance thermometer works on the principle that:

20. Two objects with heat capacities and are at 500 K and 300 K respectively. What is the final equilibrium temperature?

1. Which practical device relies directly on the Zeroth Law?

2. Why is thermodynamic modeling essential in chemical engineering?

3. Entropy in thermodynamics is defined as:

4. A heat pump delivers of heat to a room while consuming of work. What is the COP of the heat pump?

5. In a reversible isothermal compression of an ideal gas from 4 L to 2 L at 300 K with 1 mole, calculate entropy change.

6. The function of the condenser in a steam engine is:

7. In a power cycle, heat supplied is 3000 J and work obtained is 1200 J. Calculate the entropy generated if the source is at 600 K and the sink at 300 K.

8. The efficiency of a heat engine is given by:

9. Temperature is defined as:

10. The molar heat capacity at constant volume is related to specific heat by:

11. How does the Zeroth Law ensure consistency in temperature measurement?

12. Why can’t the Carnot cycle be used directly in power plants?

13. In a TS diagram, the cycle efficiency can be calculated as:

14. Which of the following is a state variable in thermodynamics?

15. The Coefficient of Performance (COP) of a heat pump is defined as:

16. The SI unit of entropy is:

17. A steam turbine in a thermal power plant produces 2000 kJ of work while receiving 5000 kJ of heat from the boiler. Calculate its efficiency.

18. Which of the following is an irreversible process?

19. Maxwell’s relation expresses relationship between:

20. An isobaric process on a PV diagram is represented by:

21. A cylinder contains 1 mole of an ideal gas undergoing a reversible adiabatic expansion. If the initial temperature is 600 K and final temperature is 300 K, calculate entropy change.

22. The work output of a Carnot cycle is equal to:

23. Which Maxwell relation connects entropy with volume and pressure with temperature?

24. Which of the following statements about internal energy is correct?

25. How many independent Maxwell’s relations exist?

26. Work done by gas in isothermal expansion is given by:

27. The principle of a heat pump is:

28. A Carnot engine rejects 1200 J of heat at 300 K and operates with 40% efficiency. Calculate the source temperature.

29. Which experiment directly established the mechanical equivalent of heat?

30. A gas expands reversibly and isothermally from 2 L to 6 L at 400 K. Calculate the entropy change for 1 mole of the gas. (Take ).

1. Which of the following processes are part of the Carnot cycle?

2. In a cyclic process, the system returns to its initial state. What is the change in internal energy after one cycle?

3. A gas initially at pressure , volume , and temperature . If it changes to pressure , volume , temperature , which of the following remains unchanged?

4. The First Law of Thermodynamics is mathematically expressed as:

5. Which thermodynamic device is most directly linked to refrigeration and air conditioning systems?

6. A refrigerator transfers heat from 270 K space to 300 K surroundings. Which law governs this requirement of external work?

7. A system absorbs 1200 J of heat reversibly at a constant temperature of 300 K. Calculate the change in entropy.

8. For an isothermal reversible expansion of an ideal gas, entropy change is:

9. A heat pump delivers of heat to a room while consuming of work. What is the COP of the heat pump?

10. Entropy is a:

11. Which principle is the basis of calorimetry?

12. A digital thermometer works on the principle of:

13. Two objects with heat capacities and are at 500 K and 300 K respectively. What is the final equilibrium temperature?

14. A Carnot heat pump operates between 280 K (inside) and 320 K (outside). If it consumes 1000 J of work, find the heat delivered to the room.

15. Which process is represented by a vertical line on a PV diagram?

16. In thermodynamics, what does the term "surroundings" mean?

17. In thermodynamic relationships, entropy is considered useful because:

18. A steam turbine in a thermal power plant produces 2000 kJ of work while receiving 5000 kJ of heat from the boiler. Calculate its efficiency.

19. A bullet of mass 0.02 kg is moving at 200 m/s. What is its kinetic energy?

20. A piece of iron of mass 500 g at is dropped into 200 g of water at . If and , the equilibrium temperature is closest to:

21. Which practical device relies directly on the Zeroth Law?

22. Why is entropy considered a measure of energy quality?

23. What is the entropy change when 1000 J of heat is absorbed reversibly at 500 K?

24. Why is the concept of thermal equilibrium important in defining temperature?

25. A Carnot refrigerator extracts 500 J of heat from a cold reservoir at 270 K and rejects it to a hot reservoir at 300 K. Calculate the work input required.

26. For an ideal gas undergoing an isothermal expansion, entropy change can be expressed as:

27. Which of the following best illustrates the significance of the Zeroth Law?

28. The SI unit of internal energy is:

29. In a Rankine cycle, the component that converts liquid water into high-pressure steam is:

30. Which of the following is a path function in thermodynamics?

31. In physical sciences, thermodynamics is significant because it:

32. A thermometer is placed in a liquid at . After some time, the thermometer reads . What does this indicate according to the Zeroth Law?

33. On a PV diagram, which cycle appears as a rectangle?

34. In a reversible isothermal process, the entropy change of an ideal gas is:

35. A gas is compressed adiabatically from 8 L at 1 atm to 2 L. If , find the final pressure.

36. For a reversible adiabatic process of an ideal gas, the relation between temperature and volume is:

37. A gas in a cylinder absorbs of heat and performs of work. What is the change in its internal energy?

38. When ice melts at 0°C, what happens to entropy? (Latent heat of fusion = 334 J/g).

39. Why are all natural processes considered irreversible?

40. In thermodynamics, which of the following is a path function?

41. Which statement correctly describes the Fahrenheit scale?

42. The significance of the Carnot engine in thermodynamics is that:

43. Why is Kelvin scale preferred in scientific thermodynamics?

44. The function of the compressor in a refrigerator is:

45. In an isochoric process, the work done is:

46. A sample of gas has volume , pressure , temperature . Calculate the number of moles. (Take ).

47. Two bodies with masses and , specific heats and , and initial temperatures and , are brought in thermal contact. The final equilibrium temperature is given by:

48. A refrigerator extracts of heat from its cold body and requires of work input. What is its coefficient of performance (COP)?

49. Which statement about reversibility is correct?

50. Why is temperature measurement important in thermodynamics?