Thermodynamics – Class 11 Physics Chapter 11 MCQ Questions with Answers (Updated)

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Last Updated on June 5, 2025 by XAM CONTENT

Mastering the important concepts in Class 11 Physics Chapter 11 – Thermodynamics is essential for scoring high marks in your exams. That’s why we’ve put together chapterwise multiple-choice questions (MCQs) with answers to help you revise effectively and boost your confidence. It is a part of MCQ Questions for CBSE Class 11 Physics Series.

These multiple-choice questions will help you assess your knowledge, improve accuracy, and boost confidence for your exams. Whether you are preparing for school tests, online tests or competitive exams, these Thermodynamics MCQs will strengthen your conceptual clarity.

ChapterThermodynamics
BookPhysics for Class 11
Type of QuestionsMCQ Questions
Nature of QuestionsCompetency Based Questions
BoardCBSE
Class11
SubjectPhysics
Useful forClass 11 Studying Students
Answers providedYes
Difficulty levelMentioned
Important LinkClass 11 Physics Chapterwise MCQ Questions

MCQ Questions on Thermodynamics Class 11 Physics (PDF Download)

MCQs

Q1. In thermodynamics, which of the following is a path function?
(a) Internal energy
(b) Work
(c) Temperature
(d) Pressure

Show Answer

Answer: (b)
Explanation: Work depends on the path taken between two states and is therefore a path function.

Q2. Which law of thermodynamics introduces the concept of temperature?
(a) First law
(b) Second law
(c) Zeroth law
(d) Third law

Show Answer

Answer: (c)
Explanation: The Zeroth Law of Thermodynamics establishes the concept of thermal equilibrium and temperature.

Q3. In a cyclic process, the net change in internal energy is:
(a) Maximum
(b) Zero
(c) Equal to the work done
(d) Equal to the heat absorbed

Show Answer

Answer: (b)
Explanation: In a cyclic process, the system returns to its initial state; thus, ∆U = 0.

Q4. A Carnot engine operates between 500 K and 300 K. Its efficiency is:
(a) 40%
(b) 60%
(c) 25%
(d) 70%

Show Answer

Answer: (a)
Explanation: Efficiency η = 1 – (T2/T1) = 1 – (300/500) = 0.4 or 40%.

Q5. For an ideal gas undergoing isothermal expansion, the internal energy:
(a) Increases
(b) Decreases
(c) Remains constant
(d) Becomes zero

Show Answer

Answer: (c)
Explanation: Internal energy of an ideal gas depends only on temperature, which is constant in isothermal process.

Q6. In an adiabatic process, the system is:
(a) Perfectly conducting
(b) Thermally insulated
(c) Always at constant pressure
(d) Always at constant temperature

Show Answer

Answer: (b)
Explanation: In adiabatic processes, no heat is exchanged due to thermal insulation.

Q7. Which of the following quantities is NOT a state function?
(a) Work
(b) Pressure
(c) Temperature
(d) Volume

Show Answer

Answer: (a)
Explanation: Work depends on the process path and is not a property of the system.

Q8. During an isobaric process, the work done by a gas is proportional to:
(a) Change in temperature
(b) Change in volume
(c) Pressure
(d) Mass of the gas

Show Answer

Answer: (b)
Explanation: W = P∆V, so work done is proportional to volume change at constant pressure.

Q9. The internal energy of a monoatomic ideal gas is proportional to:
(a) T
(b) T²
(c) √T
(d) T1/3

Show Answer

Answer: (a)
Explanation: Internal energy U = (3/2)nRT, hence directly proportional to T.

Q10. Which process is both quasi-static and reversible?
(a) Rapid compression
(b) Free expansion
(c) Isothermal expansion with infinitesimal temperature difference
(d) Explosive chemical reaction

Show Answer

Answer: (c)
Explanation: Reversibility requires quasi-static changes with infinitesimal gradients and no dissipation.

Q11. According to the first law of thermodynamics, which of the following is true?
(a) ∆Q = ∆W – ∆U
(b) ∆U = ∆Q + ∆W
(c) ∆Q = ∆U + ∆W
(d) ∆U = ∆Q – ∆W

Show Answer

Answer: (c)
Explanation: First law: Heat supplied = Change in internal energy + Work done by system.

Q12. In a Carnot engine, the ratio of heat rejected to heat absorbed is equal to:
(a) T1/T2
(b) T2/T1
(c) 1 – T2/T1
(d) ln(T2/T1)

Show Answer

Answer: (b)
Explanation: For a Carnot cycle, Q2/Q1 = T2/T1.

Q13. Which thermodynamic process involves no change in volume?
(a) Isothermal
(b) Isochoric
(c) Isobaric
(d) Adiabatic

Show Answer

Answer: (b)
Explanation: Isochoric process means volume is constant.

Q14. For an adiabatic process in an ideal gas, PVγ = constant. What does γ represent?
(a) Ratio of pressure to volume
(b) Ratio of molar heat capacities Cp/Cv
(c) Universal gas constant
(d) Molar mass

Show Answer

Answer: (b)
Explanation: γ = Cp/Cv for an ideal gas.

Q15. Which statement best defines a reversible process?
(a) System does no work
(b) Process occurs without any change
(c) System and surroundings can return to initial state
(d) System remains at constant temperature

Show Answer

Answer: (c)
Explanation: A reversible process allows both system and surroundings to revert without any net change.

Q16. The efficiency of any real engine is always less than that of a Carnot engine due to:
(a) Ideal gas assumptions
(b) Practical limitations
(c) Friction and irreversibilities
(d) Low work output

Show Answer

Answer: (c)
Explanation: Real engines involve friction, losses, and non-quasi-static processes.

Q17. Which of the following pairs are both intensive properties?
(a) Volume and Temperature
(b) Mass and Pressure
(c) Pressure and Temperature
(d) Internal energy and Volume

Show Answer

Answer: (c)
Explanation: Intensive properties do not depend on the size of the system.

Q18. The Second Law of Thermodynamics prohibits:
(a) Conversion of energy
(b) Creation of energy
(c) Complete conversion of heat into work
(d) Absorption of heat

Show Answer

Answer: (c)
Explanation: It’s impossible for heat to be fully converted into work without losses.

Q19. Entropy is a measure of:
(a) Energy content
(b) Disorder in the system
(c) Work done
(d) Heat lost

Show Answer

Answer: (b)
Explanation: Entropy quantifies randomness or disorderness in a system.

Q20. A Carnot engine absorbs 500 J heat from a source at 600 K and rejects heat to a sink at 300 K. The work done is:
(a) 250 J
(b) 300 J
(c) 400 J
(d) 200 J

Show Answer

Answer: (a)
Explanation: η = 1 – T2/T1 = 0.5; work = η × Q1 = 0.5 × 500 = 250 J.

We hope the given mcq questions with Answers for Thermodynamics Class 11 helps you in your learning.

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Topics from which mcq questions may be asked

  • Zeroth and first law of thermodynamics
  • Heat engines
  • Specific heat and internal energy

Thermodynamics explains how energy transforms and flows in nature.

Frequently Asked Questions (FAQs) on Thermodynamics MCQ Questions

Q1: What is the best way to prepare for Class 11 Physics MCQ questions?

A1: The best way is to study NCERT concepts thoroughly, practice topicwise MCQs regularly, and focus on understanding fundamental principles rather than rote learning. Solving previous year MCQs and mock tests can boost accuracy and speed.

Q2: Are NCERT questions enough for Class 11 Physics MCQ-based exams?

A2: NCERT forms the base for all CBSE Physics MCQs. However, for better preparation, students should solve additional MCQs from reference books and practice HOTS and competency-based questions to develop deeper conceptual clarity.

Q3: Where can I find chapterwise Class 11 Physics MCQ questions with answers?

A3: You can find chapterwise MCQ questions with answers and detailed explanations on trusted educational platforms like xamcontent.com and physicsgurukul.com. These cover both basic and advanced-level questions.

Q4: Do CBSE Class 11 exams include MCQs?

A4: Yes, as per the latest CBSE exam pattern, objective questions, including MCQs, are part of the final exam paper. MCQs test conceptual understanding and application skills.

Q5: How to score high in Class 11 Physics MCQs?

A5: To score high, understand the theory from NCERT, solve a variety of MCQs (basic, conceptual, numerical), and regularly revise formulas and diagrams. Avoid guesswork and focus on time management during tests.

Q6: What are competency-based MCQs in Class 11 Physics?

A6: Competency-based MCQs assess a student’s ability to apply concepts in real-life or unfamiliar scenarios. These questions go beyond textbook definitions and require logical reasoning and application of physics principles.

Thermodynamics – Class 11 Physics Chapter 11 MCQ Questions with Answers (Updated)

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