Practice portal › Electric Potential and Capacitance › Electric Potential

For any charge configuration, the equipotential surface through a point is ______ to the electric field at that point.

Asked in GSEB Board July 2021 · Equipotential surfaces and V-r graphs

Answer: (3) Normal

Step-by-step solution

Idea: V is the same everywhere on an equipotential surface, so no work is done in moving a charge along it.

For a step Δ s along the surface, W = qE Δ s cos θ, where θ is the angle between ⃗E and the step.

This vanishes for every direction lying in the surface only if ⃗E has no component along the surface, i.e. θ = 90°.

So the equipotential surface through any point is normal to the electric field there.

Why the other options are wrong

More Electric Potential questionsAll Electric Potential questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer