Assertion:In an electric bulb , the filament is in the form of a coiled coil
Reason:A coiled coil filament occupies less space and is therefore not cooled significantly by the convection currents in the bulb

Options

A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
B. Both Assertion and Reason are true but Reason is not a correct explanation of Assertion
C. Assertion is true but Reason is false
D. Assertion is false but Reason is true

Answer

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

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "In an electric bulb, the filament is in the form of a coiled coil."
- This is true because the filament in a bulb is designed to maximize the amount of light produced while minimizing the space it occupies. A coiled coil structure allows for a longer filament length in a compact space.

2. **Understanding the Reason**:
- The reason states that "A coiled coil filament occupies less space and is therefore not cooled significantly by the convection currents in the bulb."
- This is also true. The coiled design reduces the surface area exposed to the surrounding air, which in turn minimizes the heat loss due to convection.

3. **Analyzing the Relationship**:
- The reason explains why the assertion is true. The coiled coil design indeed occupies less space, which contributes to reduced cooling by convection currents.
- The assertion and reason are both correct, and the reason provides a valid explanation for the assertion.

4. **Conclusion**:
- Since both the assertion and reason are true, and the reason correctly explains the assertion, we conclude that the correct answer is:
- **Both assertion and reason are true, and the reason is the correct explanation of the assertion.**

### Final Answer:
- The answer is option A: Both assertion and reason are true, and the reason is the correct explanation of the assertion.