Last Updated on April 25, 2025 by XAM CONTENT
Hello students, we are providing assertion reason questions for class 11. Assertion Reason questions are the new question format that is introduced in CBSE board. The resources for assertion reason questions are very less. So, to help students we have created chapterwise assertion reason questions for class 11 Physics. In this article, you will find assertion reason questions for CBSE Class 11 Physics Chapter 11 Thermodynamics. It is a part of Assertion Reason Questions for CBSE Class 11 Physics Series.
| Chapter | Thermodynamics |
| Type of Questions | Assertion Reason Questions |
| Nature of Questions | Competency Based Questions |
| Board | CBSE |
| Class | 11 |
| Subject | Physics |
| Useful for | Class 11 Studying Students |
| Answers provided | Yes |
| Difficulty level | Mentioned |
| Important Link | Class 11 Physics Chapterwise Assertion Reason |
Assertion Reason Questions on Thermodynamics
Assertion Reason Questions
Directions:
Each of the following questions consists of two statements: an Assertion (A) and a Reason (R). Answer them by selecting the correct option:
(a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true.
Q1. Assertion (A): Internal energy of a system increases when heat is supplied to it.
Reason (R): According to the first law of thermodynamics, $\Delta Q=\Delta U+\Delta W$.
Answer: Option (a) is correct.
Explanation: The first law of thermodynamics directly relates heat added to a system to changes in internal energy and work done. If no work is done, all heat goes into internal energy.
Difficulty Level: Moderate
Q2. Assertion (A): In an adiabatic process, no heat is exchanged between the system and its surroundings.
Reason (R): The temperature of the system remains constant during an adiabatic process.
Answer: Option (c) is correct.
Explanation: Adiabatic processes involve no heat exchange ( $Q=0$ ), but the temperature does change because internal energy changes due to work.
Difficulty Level: Moderate
Q3. Assertion (A): In an isothermal process, the internal energy of an ideal gas remains unchanged.
Reason (R): Internal energy of an ideal gas depends only on temperature.
Answer: Option (a) is correct.
Explanation: Since temperature is constant in an isothermal process, and internal energy $U$ of an ideal gas depends only on temperature, $\Delta U=0$.
Difficulty Level: Moderate
Q4. Assertion (A): The efficiency of a Carnot engine depends on the nature of the working substance.
Reason (R): The Carnot engine is the most efficient engine possible between two heat reservoirs.
Answer: Option (d) is correct.
Explanation: Efficiency of a Carnot engine depends only on the temperatures of the heat reservoirs, not on the substance used. So A is false, R is true.
Difficulty Level: Tough
Q5. Assertion (A): The second law of thermodynamics states that heat can be completely converted into work.
Reason (R): No engine can be 100% efficient.
Answer: Option (d) is correct.
Explanation: The second law forbids complete conversion of heat into work; it actually supports the idea that no engine is 100% efficient. So the assertion is incorrect, while the reason is correct.
Difficulty Level: Tough
Also check
- Kinetic Theory Class 11 Assertion Reason Questions Physics Chapter 12
- Thermodynamics Class 11 Assertion Reason Questions Physics Chapter 11
- Thermal Properties of Matter Class 11 Assertion Reason Questions Physics Chapter 10
- Mechanical Properties of Fluids Class 11 Assertion Reason Questions Physics Chapter 9
- Mechanical Properties of Solids Class 11 Assertion Reason Questions Physics Chapter 8
- Gravitation Class 11 Assertion Reason Questions Physics Chapter 7
- System of Particles and Rotational Motion Class 11 Assertion Reason Questions Physics Chapter 6
- Work, Energy, and Power Class 11 Assertion Reason Questions Physics Chapter 5
- Laws of Motion Class 11 Assertion Reason Questions Physics Chapter 4
- Motion in a Plane Class 11 Assertion Reason Questions Physics Chapter 3
- Motion in a Straight Line Class 11 Assertion Reason Questions Physics Chapter 3
- Units and Measurements Class 11 Assertion Reason Questions Physics Chapter 2
Topics from which assertion reason questions may be asked
- First law of thermodynamics
- Second law and entropy
- Carnot engine and heat engines
The second law of thermodynamics states that entropy of an isolated system always increases — defining the direction of natural processes.
Assertion reason questions from the above given topic may be asked.
Frequently Asked Questions (FAQs) on Thermodynamics Assertion Reason Questions Class 11
Q1: What is the importance of Thermodynamics in Class 11 Physics?
A1: It forms the basis for various real-life applications and is crucial for JEE/NEET level conceptual clarity.
Q2: Are assertion reason questions asked in CBSE exams?
A2: Yes, CBSE has introduced competency-based formats which include assertion reason questions to test conceptual understanding.
Q3: How to prepare assertion reason questions from Thermodynamics?
A3: Focus on key definitions, cause-effect relationships, and conceptual reasoning instead of just memorizing facts.
Q4: Can numerical topics appear in assertion reason format?
A4: Yes, concepts from numerical topics like laws, formulas, or effects of parameter change are often asked.
Q5: Where can I find more assertion reason questions on Thermodynamics?
A5: Visit xamcontent.com and physicsgurukul.com for chapterwise assertion reason question collections.
