Which of these parts of a gold-leaf electroscope provides insulation to the gold leaves from external disturbances?

Options

A. Brass disc
B. Brass rod
C. Glass jar
D. Tin foils

Answer

To determine which part of a gold-leaf electroscope provides insulation to the gold leaves from external disturbances, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of a Gold-Leaf Electroscope**:
- A gold-leaf electroscope consists of several key components: a metal rod, gold leaves, a glass container, and a base.

2. **Identify the Role of Each Component**:
- The metal rod is used to conduct electricity.
- The gold leaves are used to detect charge.
- The glass container (or stick) is crucial for insulation.

3. **Focus on Insulation**:
- Insulation is necessary to prevent external electric fields or charges from affecting the gold leaves' behavior.

4. **Determine the Insulating Component**:
- The glass component of the electroscope is the part that provides insulation. Glass is a poor conductor of electricity, which means it effectively prevents external charges from influencing the gold leaves.

5. **Conclusion**:
- Therefore, the part of the gold-leaf electroscope that provides insulation to the gold leaves from external disturbances is the glass container or glass stick.

### Final Answer:
The glass container or glass stick of the gold-leaf electroscope provides insulation to the gold leaves from external disturbances.