Thermodynamics – Objective Questions
Page 3 : Numerical & Trap-Based (Q21–Q30)
Q21. An ideal gas absorbs 500 J of heat and does 200 J of work. The change in internal energy is:
- A) +700 J
- B) +300 J
- C) −300 J
- D) −700 J
Answer: B
Explanation: ΔU = Q − W = 500 − 200 = 300 J.
Q22. 1 mole of monoatomic ideal gas is heated at constant volume by 100 K. Change in internal energy is:
- A) 3/2 R × 100
- B) 5/2 R × 100
- C) R × 100
- D) Zero
Answer: A
Explanation: ΔU = (f/2) nRΔT = (3/2)R × 100.
Q23. Work done in an isochoric process is:
- A) Maximum
- B) Minimum
- C) Zero
- D) Depends on temperature
Answer: C
Explanation: Isochoric ⇒ ΔV = 0 ⇒ W = 0.
Q24. For an isothermal expansion of ideal gas, internal energy change is:
- A) Positive
- B) Negative
- C) Zero
- D) Depends on pressure
Answer: C
Explanation: For ideal gas, U depends only on temperature.
Q25. In an adiabatic process for ideal gas:
- A) Q = 0
- B) ΔU = 0
- C) W = 0
- D) T = constant
Answer: A
Explanation: Definition of adiabatic process.
Q26. If pressure doubles during an isothermal process, volume becomes:
- A) Double
- B) Half
- C) Same
- D) Four times
Answer: B
Explanation: PV = constant ⇒ V ∝ 1/P.
Q27. Which quantity remains constant in an isothermal process?
- A) Pressure
- B) Volume
- C) Temperature
- D) Internal energy
Answer: C
Explanation: Isothermal ⇒ temperature constant.
Q28. For an ideal gas, which statement is always true?
- A) ΔU = Q
- B) ΔU = W
- C) ΔU depends only on T
- D) ΔU depends on P and V
Answer: C
Explanation: Internal energy of ideal gas depends only on temperature.
Q29. A cyclic process has:
- A) Zero work
- B) Zero heat
- C) Zero internal energy change
- D) Zero entropy change
Answer: C
Explanation: State returns to initial ⇒ ΔU = 0.
Q30. Which process gives maximum work for given initial and final volumes?
- A) Isochoric
- B) Isobaric
- C) Isothermal
- D) Adiabatic
Answer: C
Explanation: Area under P–V curve is maximum for isothermal expansion.
Focus: Calculations + IIT trap concepts
📚 IIT–JEE PHYSICS MASTER LIBRARY (ADVANCED)
One-stop structured learning hub for JEE Advanced Physics
Concepts • Objective Questions • Final Revision • Complete Libraries
🔥 Thermodynamics – Objective Final Revision
Set 2
Set 3
Set 4
Set 5
Set 6
Set 7
Set 8
Set 9
Set 10
Set 11
Set 12
Set 13
Set 14
Set 15
Set 16
Set 17
Set 18
Set 19
Set 20
Set 21
Set 22
Set 23
Set 24
Set 25
Set 26
Set 27
Set 28
Set 29
Set 30
Set 31
Set 32
Set 33
Set 34
Set 35
Set 36
Set 37
Set 38
Set 39
Set 40
Set 41
Set 42
Set 43
Set 44
Set 45
Set 46
Set 47
Set 48
Set 49
Set 50
Set 51
Set 52
Set 53
Set 54
Set 55
Set 56
Set 57
Set 59
📘 Complete Physics Libraries
- SHM – Complete Library
- Waves – Objective Library
- Gravitation – Complete Library
- Momentum & Collisions
- Centre of Mass
- Work, Energy & Power
- WEP – Intermediate Notes
- Motion in a Plane
🔗 Learning Hubs & Community
- IIT–JEE Physics Master Library
- Physics Mega Library
- Advanced Stage-5 Material
- Shaktimatha Learning Resource Hub
- WhatsApp Learning Channel
© Mind Grow Magazine | Structured for Serious IIT–JEE Aspirants
No comments:
Post a Comment