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. A Carnot engine works between 800 K and 400 K. Its efficiency is:

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

3. Why is the Carnot engine considered idealized?

4. A steam turbine receives steam at 500 °C and exhausts it at 40 °C. If Carnot efficiency is 61%, the actual turbine efficiency is usually:

5. A refrigerator removes of heat from its cold compartment and rejects of heat to the surroundings. How much work input is required?

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

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

8. A gas is compressed adiabatically with of work done on it. No heat exchange occurs. What is the change in internal energy?

9. A 500 g piece of aluminum () is supplied with of heat. What is the rise in its temperature?

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

11. The ideal gas law is expressed as:

12. The efficiency of a Carnot engine is always:

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

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

15. A reversible Carnot engine has efficiency 40% when operating between reservoirs at 500 K and . Find the sink temperature.

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

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

18. A 0.5 kg copper block at is placed in contact with a 1 kg aluminum block at . If and , the final equilibrium temperature is:

19. In a thermal power plant, why is condenser pressure kept very low?

20. Entropy is related to probability as:

21. Which of the following processes has zero entropy generation?

22. Which process appears as a vertical line on a TS diagram?

23. Why is the Carnot cycle not practically achievable?

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

25. Why is temperature measurement important in thermodynamics?

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

27. When an ice cube is placed in a glass of water, the system reaches thermal equilibrium when:

28. Which of the following is the best example of the Zeroth Law in action?

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

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

1. Which of the following is a correct statement about entropy change in an isolated system according to the Second Law?

2. A clinical thermometer is designed to measure human body temperature accurately because:

3. 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:

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

5. A 2 kg block of copper () is heated from to . How much heat is absorbed?

6. A Carnot engine has efficiency 40% when operating between 500 K and . Find the sink temperature.

7. The working substance in a heat engine is:

8. The Brayton cycle is used in:

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

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

11. A 2 kg block of copper (specific heat capacity ) at 500 K is placed in contact with a 1 kg block of aluminum (specific heat capacity ) at 300 K, in an insulated system. Find the final equilibrium temperature.

12. A 250 g aluminum block is heated to and then placed in 500 g of water at . If the final temperature is , calculate the specific heat of aluminum. (Specific heat of water = ).

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

14. For an isentropic process, the entropy change is:

15. Which of the following is the best example of the Zeroth Law in action?

16. Which heat transfer process is primarily responsible for sea and land breezes?

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

18. The Otto cycle is the idealized cycle for:

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

20. Which statement is correct about Carnot efficiency?

21. Why are Maxwell’s relations and property relationships important in practice?

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

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

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

25. On the Celsius scale, what are the two fixed reference points traditionally used for calibration?

26. Which quantity remains constant in an isothermal process?

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

28. A calorimeter contains 250 g of water at . A 100 g piece of metal at is placed in it. Final equilibrium temperature is . Find the specific heat of the metal. (Specific heat of water = ).

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

30. Which statement about reversibility is correct?

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

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

33. Heat is rejected in the Carnot cycle during:

34. Which among the following is not a state variable?

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

36. A system absorbs of heat and does of work. Calculate the change in internal energy.

37. If body A is in thermal equilibrium with body B, and body B with body C, then which parameter is the same for all three according to the Zeroth Law?

38. Which property is extensive in thermodynamics?

39. A Carnot refrigerator working between 270 K and 300 K extracts 540 J of heat from the cold reservoir. Find the work input required.

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

41. The method commonly used in laboratories to measure specific heat capacity is:

42. Which gas deviates least from ideal behavior?

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

44. What is the main reason the Zeroth Law is foundational in thermodynamics?

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

46. Which of the following is an isolated system?

47. Why is thermodynamic modeling essential in chemical engineering?

48. A gas does of work and its internal energy decreases by . Find the heat supplied.

49. In Boltzmann’s entropy formula, represents:

50. 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 = , ).