Assertion :- Entropy is always constant for a closed system.
Reason :- Closed system is always reversible.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

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

**Assertion:** Entropy is always constant for a closed system.
**Reason:** Closed system is always reversible.

### Step-by-Step Solution:

1. **Understanding Entropy:**
- Entropy is a measure of the disorder or randomness in a system. It can change depending on the processes occurring within the system.

2. **Analyzing the Assertion:**
- The assertion states that "Entropy is always constant for a closed system." This is incorrect. In a closed system, entropy can increase, decrease, or remain constant depending on the processes (reversible or irreversible) that the system undergoes. Therefore, the assertion is **false**.

3. **Analyzing the Reason:**
- The reason states that "Closed system is always reversible." This statement is also incorrect. A closed system can undergo both reversible and irreversible processes. Thus, the reason is also **false**.

4. **Conclusion:**
- Since both the assertion and the reason are false, the correct answer is that both statements are incorrect.

### Final Answer:
Both assertion and reason are false. The correct option is **D**.

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