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 of the following is a limitation of the ideal gas law in modeling real gases?

2. A gas expands from 1 L to 3 L against a constant external pressure of . Calculate the work done by the gas. (Take ).

3. The Kelvin scale is defined by which zero reference point?

4. The Carnot cycle efficiency is expressed as:

5. In a hydroelectric power plant, which conversion of energy occurs?

6. Which of the following is true for an adiabatic process?

7. Which thermodynamic cycle is the basis of most steam power plants?

8. Entropy is significant because it:

9. Entropy is related to probability as:

10. Why are equations of state like the ideal gas law important in thermodynamic analysis?

11. Entropy change of the universe in a reversible process is:

12. The Carnot efficiency depends on:

13. Heat is rejected in the Carnot cycle during:

14. The Second Law differs from the First Law because it:

15. Which of the following best describes a refrigerator in thermodynamic terms?

16. A room air conditioner extracts 5000 kJ of heat per hour while consuming 1500 kJ of work. Calculate its COP.

17. Why is calibration of thermometers necessary?

18. In an isobaric process, the work done is calculated as:

19. The relation is called:

20. One mole of an ideal gas at STP occupies:

21. A 1 kg block of iron at 400 K and a 2 kg block of water at 300 K are placed together in an insulated system. If and , the equilibrium temperature is:

22. An ideal gas expands isothermally at 400 K from volume 4 L to 12 L. If there are 2 moles of gas, calculate the work done. (Take ).

23. A mercury thermometer is placed in hot water at . If the thermometer initially reads , what happens over time?

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

25. The Otto cycle is the idealized cycle for:

26. Which of the following is an application of Carnot efficiency in thermodynamic analysis?

27. The evaporator in a refrigerator works as:

28. Temperature is defined as:

29. In real heat engines, efficiency is always less than Carnot efficiency because:

30. Which factor must be avoided to ensure accurate calibration of thermometers?

1. For thermal equilibrium to be established, the heat transfer must continue until:

2. An ideal gas expands adiabatically from to . (). Find final pressure .

3. The Third Law of Thermodynamics states that:

4. The evaporator in a refrigerator works as:

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

6. Which of the following is a limitation of the ideal gas law in modeling real gases?

7. A resistance thermometer works on the principle that:

8. Which condition ensures accurate temperature measurement using a thermometer?

9. Entropy change of the universe in a reversible process is:

10. A reversible engine rejects 600 J of heat to a sink at 300 K. If its efficiency is 40%, what is the temperature of the source?

11. Which of the following best describes the role of insulation in achieving thermal equilibrium in experiments?

12. Entropy change for mixing two different ideal gases is:

13. The Boltzmann entropy formula is:

14. In practice, why must a heat engine always reject some heat to a sink?

15. Which process in heat exchangers leads to entropy generation?

16. A Carnot engine works between reservoirs at 800 K and 400 K. If it absorbs 1200 J of heat per cycle, find the work done and heat rejected.

17. In refrigeration systems, the throttling process (expansion valve) is considered irreversible because:

18. A gas expands from 1 L to 3 L against a constant external pressure of . Calculate the work done by the gas. (Take ).

19. Convert into Kelvin.

20. Which of the following is correct for an isothermal process involving an ideal gas?

21. Air conditioners are practical applications of which thermodynamic system?

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

23. The entropy change of the universe in any real adiabatic process is:

24. The efficiency of a Carnot engine approaches 100% when:

25. Which 17th-century scientist first hinted at energy conservation through chemical processes?

26. A Carnot engine operates between a hot reservoir at 900 K and a cold reservoir at 300 K. If it absorbs 6000 J of heat from the hot reservoir, calculate (i) work done, and (ii) heat rejected.

27. The efficiency of a reversible heat engine working between two reservoirs depends on:

28. The SI unit of specific heat capacity is:

29. Which of the following statements best represents the First Law of Thermodynamics?

30. A 2 kg object is dropped from a height of 10 m. Ignoring air resistance, what is its kinetic energy just before hitting the ground? (Take ).

31. Which component is common in both refrigerators and heat pumps?

32. Why is the study of entropy important in physical sciences?

33. In a calorimeter experiment, a hot solid of mass 100 g at is dropped into 200 g of water at . If the final equilibrium temperature is , calculate the specific heat of the solid. (Specific heat of water = ).

34. Which of the following is an isolated system?

35. Who gave the First Law of Thermodynamics its modern form?

36. A real gas behaves most like an ideal gas under conditions of:

37. In which medical application does thermodynamics play a role?

38. Which statement about reversibility is correct?

39. The relation between COP of a refrigerator and heat pump is:

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

41. Which of the following is not a mechanism of heat transfer?

42. Why are all natural processes considered irreversible?

43. Which of the following processes is practically irreversible?

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

45. A 2 mole ideal gas is heated at constant volume from 300 K to 400 K. Find the heat supplied. (For a monoatomic gas, , ).

46. If the number of microstates of a system doubles, the entropy change is:

47. In an isobaric process, the work done is calculated as:

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

49. Heat transfer by radiation follows which law?

50. Heat in thermodynamics is defined as: