Question

Define an equipotential surface. Draw equipotential surfaces :

(i) in the case of a single point charge and
(ii) in a constant electric field in Z-direction.

Why the equipotential surfaces about a single charge are not equidistant ?
(iii) Can electric field exist tangential to an equipotential surface ? Give reason.

Answer 1

An equipotential surface is the surface which has same potential at its every point.


(i)

(ii)
The electric field due to single charge is not constant, this is the reason why the equipotential surfaces about a single charge are not equidiatant.
(iii) No, electric field cannot exist tangential to an equipotential surface. If it happen then a charged particle will experience a force along the tangential line and can move along it. As a charged particle can move only due to the potential difference i.e., along the direction of charge of potential, this contradicts the concept of an equipotential surface.