Capacity of a conductor.

Explanation

### Step-by-Step Solution:

1. **Understanding the Concept of Capacity**:
- The capacity of a conductor refers to its ability to store electric charge. It is a fundamental property that helps in understanding how conductors behave in an electric field.

2. **Defining Potential Difference**:
- Potential difference (V) is the difference in electric potential between two points in a circuit. It is necessary for the flow of charge (current) through a conductor.

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