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

2. Entropy change of an ideal gas can also be written in terms of and as:

3. The SI unit of entropy is:

4. Work done by gas in isothermal expansion is given by:

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

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

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

8. A 0.5 kg ball is rolling with velocity 4 m/s. Its kinetic energy is:

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

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

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

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

13. The gas constant has the value:

14. A thermometer placed in boiling water reads 100 °C. Why does it stop rising after reaching that value?

15. A cylinder contains 2 moles of an ideal gas at 300 K. Using the ideal gas law, calculate the pressure if the volume is 5 L. (Take ).

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

17. Maxwell’s relation derived from Helmholtz free energy is:

18. In thermodynamics, which of the following is a path function?

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

20. In practice, why can’t refrigerators or heat pumps achieve infinite COP as predicted when ?

21. A reservoir at 500 K supplies 2000 J of heat to a reversible engine. Calculate the entropy change of the reservoir.

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

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

24. The Carnot cycle is based on which principle?

25. Why are property relations between useful in thermodynamics?

26. For an ideal gas, the ratio of specific heats is defined as:

27. A system absorbs of heat and performs of work. Which statement is correct?

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

29. The ideal gas law is expressed as:

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

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

2. Why are all natural processes considered irreversible?

3. One mole of a diatomic ideal gas () is compressed adiabatically from 10 L at 300 K to 5 L. Find the final temperature.

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

5. Which of the following applications is directly based on the concept of thermal equilibrium?

6. The gas constant has the value:

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

8. 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 = ).

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

10. One mole of diatomic ideal gas at has internal energy: (Take ).

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

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

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

14. A reservoir at 500 K supplies 2000 J of heat to a reversible engine. Calculate the entropy change of the reservoir.

15. The concept of reversibility in thermodynamics refers to:

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

17. Which of the following represents work transfer in thermodynamics?

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

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

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

21. Which of the following processes has zero change in entropy?

22. A calorimeter of mass 150 g contains 200 g of water at . A 100 g hot solid is dropped into it, and equilibrium is reached at . If the solid was initially at and specific heat of calorimeter copper = , calculate the specific heat of the solid. (Specific heat of water = )

23. In a Rankine cycle, the component that converts liquid water into high-pressure steam is:

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

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

26. Which Maxwell relation directly relates entropy with pressure and volume with temperature?

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

28. The statistical definition of entropy was given by:

29. Which quantity remains constant in an isothermal process?

30. Calculate the pressure of 1 mole of gas at 300 K in 10 L using Van der Waals equation, given , , .

31. Which of the following engines is used in nuclear power plants for converting steam energy into electricity?

32. The Otto cycle is the idealized cycle for:

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

34. In the Carnot cycle, work is produced during:

35. Which type of system exchanges both energy and matter with surroundings?

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

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

38. Which of the following is a limitation of the Carnot engine?

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

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

41. In an air conditioning system, the evaporator coil is responsible for:

42. The efficiency of a Carnot engine operating between 1000 K and 400 K is:

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

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

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. The entropy of an isolated system:

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

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

49. Which statement correctly describes the Fahrenheit scale?

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