A : For a given conductor , electric current does not vary even if its cross sectional area varies .
R : A conductor remains unchanged when current flows through it .

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark.
C. If Assertion is ture statement but Reason is false , then mark
D. If both Assertion and Reason are false statements then mark.

Answer

To analyze the given statements and determine their validity, we can break down the reasoning step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that for a given conductor, electric current does not vary even if its cross-sectional area varies.
- This is based on the principle of conservation of charge. In a steady-state current, the amount of charge entering a section of the conductor must equal the amount of charge leaving that section.

2. **Analyzing the Current in Varying Cross-Sections**:
- If the cross-sectional area of the conductor changes, the current (I) must remain constant throughout the conductor.
- This is because if the current were to change, it would imply that charge is accumulating in the conductor, which contradicts the steady flow of current.

3. **Understanding the Reason (R)**:
- The reason states that a conductor remains unchanged when current flows through it.
- This means that the conductor does not accumulate charge; instead, it allows charge to flow continuously without any build-up.

4. **Connecting the Assertion and Reason**:
- The assertion (A) is correct because the current remains constant regardless of changes in cross-sectional area.
- The reason (R) is also correct because the conductor does not store charge, allowing for a continuous flow of current.

5. **Conclusion**:
- Both the assertion and the reason are correct, and the reason provided explains the assertion adequately.

### Final Answer:
Both A and R are correct, and R is the correct explanation of A.

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