# Equipotential Line

Show/Hide Sub-topics (Electric fields | A Level)

An equipotential line is a line joining points having the same potential.

• If an object is moved from one point on a line of equipotential to another point on the same line, there is no change in its potential. Hence, no work is done.
• Equipotential Lines are always perpendicular to electric field lines.

Distance between lines for equal increment of potential for electric field due to point charges is always increasing.

Distance between lines for equal increment of potential for electric field due to parallel plate is always the same.

A positive test charge will tend to move to a lower potential while a negative test charge will tend to move to a higher potential.

The field strength at a point is numerically equal to the potential gradient at that point.

$E = \, – \frac{dV}{dr}$

$E = \, – \frac{\Delta V}{\Delta r}$

, only applicable for parallel plates