Assertion : When the length of a conductor is doubled, its resistance will also get doulbed.
Reason : Resistance is direclty proportional to the length of a conductor.

Options

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

Explanation

To solve the question, we will analyze the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that when the length of a conductor is doubled, its resistance will also get doubled.

### Step 2: Understand the Reason
The reason states that resistance is directly proportional to the length of a conductor. This is a fundamental principle in physics.

### Step 3: Recall the Formula for Resistance
The resistance \( R \) of a conductor can be expressed using the formula:
\[ R = \rho \frac{L}{A} \]
where:
- \( R \) is the resistance,
- \( \rho \) is the resistivity of the material,
- \( L \) is the length of the conductor,
- \( A \) is the cross-sectional area of the conductor.

### Step 4: Analyze the Effect of Doubling the Length
If the length \( L \) of the conductor is doubled (i.e., \( L' = 2L \)), the new resistance \( R' \) can be calculated as:
\[ R' = \rho \frac{L'}{A} = \rho \frac{2L}{A} = 2 \left( \rho \frac{L}{A} \right) = 2R \]
This shows that when the length of the conductor is doubled, the resistance also doubles.

### Step 5: Conclusion
Both the assertion and the reason are true. The assertion is correct because it follows directly from the reason, which states that resistance is directly proportional to the length of the conductor.

### Final Answer
- Assertion: True
- Reason: True
- Conclusion: The assertion is correct because the reason is valid.

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