Which of the following is a good conductor of heat but a bad conductor of electricity ?

Options

A. Celluloid
B. Rubber
C. Asbestos
D. Mica

Answer

To determine which material is a good conductor of heat but a bad conductor of electricity, we can analyze the properties of each option provided: Celluloid, Abastor, Rubber, and Mica.

### Step-by-Step Solution:

1. **Understanding Conductivity**:
- Conductors of heat are materials that allow thermal energy to pass through them easily.
- Conductors of electricity are materials that allow electric current to flow through them easily.

2. **Analyzing Each Option**:
- **Celluloid**: This is a type of plastic that is generally an insulator for both heat and electricity.
- **Abastor**: This is a less common material, but it is often used in electrical insulation, indicating it is not a good conductor of electricity.
- **Rubber**: Rubber is known to be a very good insulator for both heat and electricity.
- **Mica**: Mica is known for its excellent thermal conductivity, meaning it can conduct heat well. However, it does not have free electrons, which makes it a poor conductor of electricity.

3. **Conclusion**:
- Among the options, Mica is the only material that is a good conductor of heat while being a bad conductor of electricity.

### Final Answer:
**Mica** is a good conductor of heat but a bad conductor of electricity.