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

2. What does thermal equilibrium mean for two bodies in contact?

3. A heat engine absorbs of heat from a source and rejects to the sink. What is the work output?

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

5. Which of the following factors reduces efficiency of real thermodynamic systems?

6. 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.

7. The device that reduces pressure of the refrigerant before entering the evaporator is called:

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

9. For an irreversible adiabatic process, entropy change of the system is:

10. Which cycle is commonly used in steam power plants as a practical alternative to Carnot?

11. Why are fixed points like the freezing and boiling points of water important in thermometer calibration?

12. Which statement is correct regarding COP of real systems?

13. Which of the following is the Clausius statement of the Second Law?

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

15. A metal rod of length 1 m and cross-sectional area has thermal conductivity . If its ends are maintained at and , the rate of heat conduction is:

16. A mole of ideal gas expands isothermally at 300 K from 5 L to 10 L. Calculate the work done. (Take ).

17. Heat transfer by radiation follows which law?

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

19. Which of the following is an example of a reversible process?

20. One mole of ideal gas expands isothermally from volume to at temperature . Calculate the work done. (Take ).

21. An isothermal process on a PV diagram appears as:

22. A 200 g block of copper at is dropped into 300 g of water at . If and , find the equilibrium temperature.

23. A Carnot engine operates between and . If the engine delivers 1200 J of work per cycle, calculate the heat absorbed .

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

25. The SI unit of internal energy is:

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

27. Why is the ideal gas law often used in preliminary thermodynamic analysis instead of the Van der Waals equation?

28. The basic principle of a refrigerator is:

29. In an isothermal process, which parameter remains constant?

30. The concept of reversibility in thermodynamics refers to:

1. Why can’t all absorbed heat energy be converted into work in energy conversion devices?

2. Carnot’s theorem states that:

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

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

5. Which component of an air conditioner circulates refrigerant between the condenser and evaporator?

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

7. Heat transfer by radiation follows which law?

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

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

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

11. One mole of an ideal gas expands isothermally at 400 K from 2 L to 20 L. Calculate the work done and entropy change. (Take ).

12. What is the condition for no net heat transfer between two systems?

13. In a reversible adiabatic process of an ideal gas, entropy change is:

14. Why are fixed points like the freezing and boiling points of water important in thermometer calibration?

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

16. Which statement is true for all heat engines?

17. A 500 g block of unknown metal is heated to and placed in 200 g of water at . Final temperature becomes . Find the specific heat of the metal. (Specific heat of water = ).

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

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

20. A Carnot engine operates between a source at 600 K and sink at 300 K. Find its efficiency.

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

22. Why is the Carnot cycle not practically achievable?

23. Entropy is best described as:

24. The Third Law of Thermodynamics states that:

25. A gas is compressed by doing of work on it. During compression, the gas loses of heat to the surroundings. What is the change in internal energy?

26. Which of the following is a major application of heat pumps in climate control?

27. Which Maxwell relation helps in calculating change in entropy with respect to volume?

28. Entropy change for an ideal gas in terms of and is:

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

30. Which of the following is an example of a reversible process?

31. If in the First Law of Thermodynamics, which relation holds true?

32. In convection, heat transfer occurs due to:

33. A 500 g block of aluminum at is mixed with 200 g of water at . If and , calculate the final equilibrium temperature.

34. Which of the following is the Clausius statement of the Second Law?

35. The Carnot engine is based on the principle of:

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

37. Which statement best summarizes the applications of Carnot efficiency?

38. A 50 g ice cube at is dropped into 200 g of water at . Find the final temperature after thermal equilibrium is reached. (Latent heat of fusion of ice = , specific heat of water = ).

39. Which of the following processes is practically irreversible?

40. Which scientist introduced the concept of entropy?

41. A metal rod of length 1 m and cross-sectional area has thermal conductivity . If its ends are maintained at and , the rate of heat conduction is:

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

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

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

45. 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.

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

47. In calorimetry experiments, why is a calorimeter usually made of copper?

48. Which of the following conditions must be ensured for accurate calorimetry measurement?

49. A resistance thermometer works on the principle that:

50. Two objects, A and B, are in thermal equilibrium. Object B is also in thermal equilibrium with object C. According to the Zeroth Law: