What do you mean by an equipotential surface?

Explanation

### Step-by-Step Solution:

1. **Definition of Equipotential Surface**: An equipotential surface is defined as the locus of points in an electric field where the electric potential is the same. This means that every point on this surface has the same electric potential value.

2. **Understanding Electric Potential**: Electric potential (often denoted as V) is the amount of electric potential energy per unit charge at a point in an electric field. When we say that the potential is the same across a surface, it implies that no work is done when moving a charge along that surface.

3. **Characteristics of Equipotential Surfaces**:
- **Perpendicular to Electric Field Lines**: Equipotential surfaces are always perpendicular to the electric field lines. This means that if you were to visualize electric field lines, they would intersect the equipotential surfaces at right angles.
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