NEET UG - Heat, work and internal energy, first law of thermodynamics, isothermal and adiabatic processes Online Test (MCQ Quiz)

1. What is the SI unit of heat?

A) Celsius B) Joule C) Watt D) Calorie

2. Which of the following is a measure of the internal energy of a system?

A) Temperature B) Pressure C) Volume D) Heat

3. Work done by a gas during expansion is considered:

A) Positive B) Negative C) Zero D) Dependent on temperature

4. According to the First Law of Thermodynamics, the change in internal energy of a system is equal to:

A) Heat supplied plus work done by the system B) Heat supplied minus work done by the system C) Work done by the system minus heat supplied D) Heat supplied multiplied by work done

5. In an isothermal process, the temperature of the system remains:

A) Constant B) Increasing C) Decreasing D) Zero

6. During an adiabatic process, there is no exchange of ______ between the system and its surroundings.

A) Work B) Heat C) Volume D) Pressure

7. For an ideal gas undergoing an isothermal process, the change in internal energy is:

A) Always positive B) Always negative C) Zero D) Dependent on pressure

8. In an adiabatic expansion of an ideal gas, the gas:

A) Warms up B) Cools down C) Maintains constant temperature D) Experiences no temperature change

9. The First Law of Thermodynamics is a statement of the conservation of:

A) Mass B) Momentum C) Energy D) Charge

10. If a system absorbs heat (Q > 0) and does work (W > 0), its internal energy change (ΔU) is given by:

A) ΔU = Q + W B) ΔU = Q - W C) ΔU = W - Q D) ΔU = -Q - W

11. In an isothermal process, PV = constant. If the volume of an ideal gas is doubled, its pressure becomes:

A) Double B) Half C) Four times D) One-fourth

12. For an adiabatic process, the relationship between pressure and volume is given by:

A) PV^γ = constant B) PV = constant C) V/T = constant D) P/T = constant

13. The term 'γ' (gamma) in the adiabatic process equation represents the ratio of:

A) Specific heat at constant volume to specific heat at constant pressure B) Specific heat at constant pressure to specific heat at constant volume C) Molar specific heat at constant volume to gas constant D) Molar specific heat at constant pressure to gas constant

14. If heat is supplied to a system and no work is done by the system, then the change in internal energy is equal to:

A) Zero B) The heat supplied C) The negative of the heat supplied D) The work done

15. When a gas expands adiabatically, its internal energy:

A) Increases B) Decreases C) Remains constant D) Becomes zero

16. Which thermodynamic process is characterized by constant volume?

A) Isothermal B) Adiabatic C) Isobaric D) Isochoric

17. In an isobaric process, the ______ remains constant.

A) Volume B) Temperature C) Pressure D) Internal energy

18. If a system does work on the surroundings and no heat is exchanged, its internal energy:

A) Increases B) Decreases C) Remains constant D) Becomes equal to the work done

19. For an ideal gas, the internal energy depends only on:

A) Pressure B) Volume C) Temperature D) Heat capacity

20. What is the work done by an ideal gas during an isothermal expansion from volume V1 to V2 at temperature T?

A) nRT ln(V2/V1) B) nRT (V2 - V1) C) nR(T2 - T1) D) 0

21. In a cyclic process, the net change in internal energy of the system is:

A) Always positive B) Always negative C) Zero D) Equal to the net heat exchanged

22. Which statement is true for an adiabatic process?

A) ΔQ = 0 B) ΔT = 0 C) ΔW = 0 D) ΔU = 0

23. The internal energy of a system increases if:

A) Heat is removed and work is done by the system B) Heat is supplied and work is done on the system C) Heat is removed and work is done on the system D) Heat is supplied and work is done by the system

24. In an isothermal compression, work is done ______ the system, and heat is ______.

A) by, absorbed B) on, released C) on, absorbed D) by, released

25. The equation of state for an adiabatic process for an ideal gas is:

A) PV^γ = constant B) PV = nRT C) V/T = constant D) P/T = constant

26. What happens to the temperature of a gas during adiabatic expansion?

A) It increases B) It decreases C) It remains constant D) It depends on the amount of gas

27. Which process involves no change in volume?

A) Isothermal B) Adiabatic C) Isobaric D) Isochoric

28. The First Law of Thermodynamics can be written as ΔQ = ΔU + ΔW. Here, ΔW represents:

A) Work done on the system B) Work done by the system C) Change in volume D) Change in pressure

29. If ΔU is positive and ΔW is negative (work done on the system), then ΔQ must be:

A) Positive B) Negative C) Zero D) Cannot be determined

30. In an isothermal process, the product of pressure and volume (PV) for an ideal gas is:

A) Variable B) Constant C) Zero D) Dependent on heat

31. During an adiabatic process, the ratio of work done to the change in internal energy is:

A) γ B) 1/γ C) γ-1 D) 1/(γ-1)

32. Which type of process requires the system to be perfectly insulated from its surroundings?

A) Isothermal B) Isobaric C) Isochoric D) Adiabatic

33. If 100 J of heat is supplied to a system and the work done by the system is 30 J, the change in internal energy is:

A) 70 J B) 130 J C) -70 J D) -130 J

34. An ideal gas is compressed isothermally. What happens to its internal energy?

A) Increases B) Decreases C) Remains the same D) Becomes zero

35. In an adiabatic process, if the volume decreases, the pressure:

A) Decreases B) Increases C) Remains constant D) Becomes zero

36. The specific heat capacity of a gas at constant volume is denoted by:

A) Cp B) Cv C) R D) γ

37. The specific heat capacity of a gas at constant pressure is denoted by:

A) Cp B) Cv C) R D) γ

38. For an ideal monatomic gas, the value of γ is approximately:

A) 1.4 B) 1.67 C) 1.33 D) 1.2

39. For an ideal diatomic gas, the value of γ is approximately:

A) 1.4 B) 1.67 C) 1.33 D) 1.2

40. In the First Law of Thermodynamics, if work is done on the system (W < 0) and heat is released by the system (Q < 0), then ΔU = Q - W becomes:

A) ΔU = (-Q) - (-W) B) ΔU = Q + W C) ΔU = Q - W D) ΔU = -Q + W

41. An isothermal process is a slow process because:

A) Heat transfer is rapid B) Work done is zero C) Temperature change is zero D) Heat transfer is slow enough to maintain constant temperature

42. A process in which no heat enters or leaves the system is called:

A) Isothermal B) Isobaric C) Isochoric D) Adiabatic

43. What is the work done when a gas expands from volume V1 to V2 at constant pressure P?

A) P(V2 - V1) B) P(V1 - V2) C) 0 D) P/(V2 - V1)

44. Which of the following correctly represents the relationship between Cp, Cv, and R for an ideal gas?

A) Cp - Cv = R B) Cv - Cp = R C) Cp + Cv = R D) Cp * Cv = R

45. The internal energy of a system is a function of:

A) Pressure only B) Volume only C) Temperature only D) Pressure, Volume, and Temperature

46. During an adiabatic process, the work done by the gas is given by:

A) nCv(T1 - T2) B) nCp(T1 - T2) C) nR(T1 - T2) D) 0

47. If heat is added to a system at constant volume, all the heat energy goes into increasing the:

A) Work done B) Internal energy C) Temperature D) Pressure

48. In an isothermal process, the change in internal energy of an ideal gas is zero because:

A) Pressure is constant B) Volume is constant C) Temperature is constant D) Heat exchanged is zero

49. Which process is represented by the equation P V^γ = constant?

A) Isothermal B) Isobaric C) Isochoric D) Adiabatic

50. When a gas undergoes an adiabatic expansion, its final temperature is:

A) Higher than the initial temperature B) Lower than the initial temperature C) Equal to the initial temperature D) Unrelated to the initial temperature

Heat, work and internal energy, first law of thermodynamics, isothermal and adiabatic processes - Online Test

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