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 100 g piece of metal at is dropped into 200 g of water at . Final temperature is . Calculate the specific heat of the metal. (Specific heat of water = )

2. A gas undergoes a reversible adiabatic compression from volume 4 L to 1 L. The entropy change is:

3. Convert normal human body temperature into Celsius.

4. 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.

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

6. The Coefficient of Performance (COP) of a refrigerator is defined as:

7. Internal energy of a system includes:

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

9. Which of the following is NOT a component of a heat engine?

10. Which of the following is NOT an example of conservation of energy in action?

11. The gas constant has the value:

12. 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?

13. Which statement about heat and work is correct?

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

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

16. If the temperature of the sink in a Carnot engine is lowered, its efficiency will:

17. A cylinder with 1 mole of a diatomic ideal gas is compressed adiabatically from 10 L to 2 L. If initial temperature is 300 K, calculate the final temperature. ()

18. In climate control systems, why is humidity control important?

19. Which property equalizes when two systems are in thermal equilibrium according to the Zeroth Law?

20. Entropy is a:

21. Calculate the molar specific heat at constant volume () for a diatomic ideal gas at room temperature.

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

23. A Van der Waals gas has constants , . For 1 mole of gas at 300 K and volume 10 L, calculate pressure using Van der Waals equation. (Take ).

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

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

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

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

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

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

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

1. A reversible heat engine absorbs 500 J from a reservoir at 400 K and rejects 300 J to a sink at 300 K. Find the total entropy change of the universe.

2. Why is calibration of thermometers necessary?

3. Which principle is the basis of calorimetry?

4. In an isothermal expansion of an ideal gas, the work done is given by:

5. A system has microstates. Calculate its entropy. (Take ).

6. The principle of a heat pump is:

7. The efficiency of the Carnot engine is independent of:

8. Which statement correctly explains entropy change in natural processes?

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

10. Why is Kelvin scale preferred in scientific thermodynamics?

11. A heat engine absorbs of heat and rejects to the sink. Find its efficiency.

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

13. What does the Zeroth Law of Thermodynamics state?

14. Which statement about reversibility is correct?

15. The Carnot theorem states that:

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

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

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. The working substance in a Carnot engine can be:

20. 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 = ).

21. A reversible process is defined as one which:

22. A 0.1 kg piece of iron at is placed in 0.2 kg water at . If and , the final equilibrium temperature is:

23. The SI unit of specific heat capacity is:

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

25. A Carnot refrigerator operates between 250 K and 300 K. If it requires 500 J of work per cycle, find the heat absorbed from the cold reservoir.

26. Which relation is true for a perfect gas?

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

28. The unit “calorie” is defined as:

29. Which of the following is an isolated system?

30. 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 = , ).

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

32. Which of the following is an intensive property in thermodynamics?

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

34. Which refrigerant was widely used in older air conditioners but phased out due to ozone depletion?

35. Calibration of thermometers requires reference points. Which two are most commonly used?

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

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

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

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

40. Which quantity remains constant in an isothermal process?

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

42. A resistance thermometer works on the principle that:

43. Maxwell’s relations are derived from which thermodynamic principle?

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

45. A Carnot engine absorbs 1000 J of heat from a reservoir at 600 K and rejects heat to a sink at 300 K. How much work is produced?

46. In convection, heat transfer occurs due to:

47. The entropy change when 2 kg of ice at 0 °C melts to water at 0 °C is (latent heat of fusion ).

48. 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 ).

49. Which modern technology improves the efficiency of air conditioners and climate control systems?

50. Two bodies A and B, with heat capacities and , are initially at and . If they are placed in contact in an isolated system, the final equilibrium temperature is: