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

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

3. Which of the following is the reversibility criterion for a thermodynamic process?

4. A body of mass 1 kg is thrown vertically upwards with velocity 20 m/s. Ignoring air resistance, what maximum height will it reach? (Take ).

5. The Carnot cycle consists of which processes?

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

7. A gas expands adiabatically and does of work. What is the change in internal energy?

8. Why is the Carnot engine considered a standard of comparison for real engines?

9. If a Carnot engine absorbs 2000 J of heat from a source at 600 K and rejects heat to a sink at 300 K, how much work does it do?

10. One mole of an ideal gas expands isothermally from 2 L to 10 L at 300 K. Calculate the entropy change. (Take )

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

12. Why can no real engine achieve Carnot efficiency?

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

14. A 2 kg block of water at 300 K is mixed with 3 kg of water at 350 K in an insulated container. Find the final temperature. (Specific heat of water ).

15. The efficiency of a Carnot engine between 800 K and 300 K is:

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

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

18. The change in entropy () for a reversible process is given by:

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

20. The Zeroth Law of Thermodynamics allows us to define:

21. 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:

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

23. 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:

24. In aerospace engineering, thermodynamics is essential for:

25. The principle of calorimetry is based on:

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

27. Which of the following processes is practically irreversible?

28. A system undergoes a reversible isothermal expansion at 350 K, absorbing 3500 J of heat. Calculate entropy change of system, surroundings, and universe.

29. A hot cup of tea placed in a cooler room eventually cools down. When does thermal equilibrium occur?

30. A steel ball of mass 0.2 kg at is dropped into 0.5 kg water at . If and , the equilibrium temperature is:

1. A refrigerator absorbs 1200 J of heat from the cold reservoir and requires 400 J of work input. Find its COP.

2. Why is entropy analysis important in practical power cycles?

3. Thermodynamics helps in chemical engineering mainly by:

4. Which of the following correctly converts 0 °C into Fahrenheit?

5. One mole of an ideal gas at 300 K is heated at constant pressure until its volume doubles. Find the entropy change. ()

6. The Second Law of Thermodynamics introduces the concept of:

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

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

9. Which of the following is a necessary condition for achieving thermal equilibrium between two bodies?

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

11. If a Carnot engine absorbs 2000 J of heat from a source at 600 K and rejects heat to a sink at 300 K, how much work does it do?

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

13. Which equation represents conservation of energy in the First Law of Thermodynamics?

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

15. Which cycle is used as a practical alternative to Carnot in gas turbine power plants?

16. Heat is rejected in the Carnot cycle during:

17. The statistical definition of entropy was given by:

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

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

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

21. The Boltzmann constant has the value:

22. Which statement about heat and work is correct?

23. The Celsius scale is calibrated such that:

24. A 2 kg block of water at 300 K is mixed with 3 kg of water at 350 K in an insulated container. Find the final temperature. (Specific heat of water ).

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

26. The SI unit of entropy is:

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

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

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

30. A hot cup of tea placed in a cooler room eventually cools down. When does thermal equilibrium occur?

31. A steel ball of mass 0.2 kg at is dropped into 0.5 kg water at . If and , the equilibrium temperature is:

32. A 1 mole ideal gas expands isothermally at 400 K from volume 5 L to 10 L. Calculate entropy change. (Take )

33. A gas undergoes isochoric heating where its temperature increases by 50 K. Which statement is correct?

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

35. In the equation , what does the term represent?

36. The SI unit of heat is:

37. Which of the following represents the efficiency of a heat engine?

38. Why is entropy important in heat transfer processes?

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

40. The practical implication of entropy increase in real thermodynamic systems is:

41. A gas undergoes an isothermal expansion from 2 L to 8 L at 300 K. Calculate the heat absorbed if 1 mole of the gas is used. (Take ).

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

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

44. Which of the following best explains the First Law of Thermodynamics?

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

46. The principle of a heat pump is:

47. A practical application of Maxwell’s relation in engineering is:

48. The change in entropy () for a reversible process is given by:

49. A system of 1 mole of ideal gas expands from 2 L to 4 L at 300 K reversibly. Calculate entropy change. (Take )

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