Assertion: A heat engine is the reverse of a refrigerator.
Reason : A refrigerator cannnot work without some external work done on the system

Options

A. If both assetion and reason are true and reaasons is the correct expanation of assetion
B. If both assetion and reason are tur but reason is not the correct explanation of assetion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "A heat engine is the reverse of a refrigerator."
- A heat engine operates by converting heat energy into work. It absorbs heat from a high-temperature source, performs work, and then releases some waste heat to a low-temperature sink.

2. **Understanding the Reason**:
- The reason states that "A refrigerator cannot work without some external work done on the system."
- A refrigerator works by removing heat from a low-temperature reservoir and transferring it to a high-temperature reservoir. This process requires work input, typically done by a compressor or another mechanical device.

3. **Analyzing the Relationship**:
- The assertion claims a relationship between a heat engine and a refrigerator. Since a heat engine converts heat to work, while a refrigerator requires work to transfer heat from a cold to a hot body, we can see that they are indeed opposite processes.

4. **Verifying the Truth of Each Statement**:
- Both the assertion and reason are true statements based on the principles of thermodynamics.
- The assertion correctly describes the relationship between a heat engine and a refrigerator.
- The reason accurately describes the necessity of work input for a refrigerator to function.

5. **Conclusion**:
- Since both the assertion and the reason are true, and the reason provides a correct explanation for the assertion, we conclude that the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
Both assertion and reason are true, and the reason is the correct explanation of the assertion.

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