Assertion :- For an isolated system q is zero.
Reason :- In an isolated system change in U and V is zero.

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 analyze the given assertion and reason, let's break down the statements step by step.

### Step 1: Understanding the Assertion
**Assertion:** For an isolated system, q is zero.

- An isolated system is defined as a system that does not exchange heat (q) or work (w) with its surroundings. Since there is no heat transfer in an isolated system, we conclude that \( q = 0 \).

### Step 2: Understanding the Reason
**Reason:** In an isolated system, change in U and V is zero.

- In an isolated system, since there is no heat or work exchange, the internal energy (U) remains constant. Therefore, the change in internal energy \( \Delta U = 0 \).
- Additionally, for an isolated system, the volume (V) does not change because there is no work done on or by the system. Thus, \( \Delta V = 0 \).

### Step 3: Connecting Assertion and Reason
- The assertion states that \( q = 0 \) for an isolated system, which is correct.
- The reason states that both \( \Delta U \) and \( \Delta V \) are zero, which is also correct.
- The reason provides a valid explanation for the assertion because if there is no change in internal energy and volume, it supports the conclusion that heat transfer is not occurring.

### Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion.

### Final Answer
- **Assertion:** True
- **Reason:** True
- **Explanation:** The reason is a correct explanation of the assertion.

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