Define an equipotential surface. Draw equipotential surfaces :
`(i)` in the case of 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 ? Given reason.

Explanation

(i) An equipotential surface is that at every point of which electric potential is the same. Due to a single point charge, equipotnetial surfaces are centred at the
charge, As `V prop (1)/(r )`, the equipotential surfaces
about a single charge cannot be equidistant.
(ii) In a constant electric field in Z- direction, equipotential surfaces lie in XY plane perpendicular to Z-direction as shown in Fig.

(iii) As electric fied is perpendicular to the equipotential surface, the field cannot exist tangenital to the equipotential surface.