Question

Define an equipotential surface,. Draw equipotential surfaces: In a constant electric field in Z - direction Why the equipotential surface about a single charge are not equidistant?

Answer 1

An equipotential surface is the surface with a constant value of potential at all points on the surface. Equipotential surface :
In case of electric field in Z -direction
Potential of a point charge at a distance $$r = \dfrac{1}{4\pi \varepsilon _{0}} \dfrac{q}{r}$$
$$\therefore V \alpha \dfrac{1}{r}$$
Hence equipotential surface about a single chrge are not equidistant.