Draw $$3$$ equipotential surface corresponding to a field that uniformly increases in magnitude but remains constant along Z-direction. How are these surface different from that of a constant electric field along Z-direction?
For constant electric field $$\underset{E}{\rightarrow}$$ For increasing electric field
Difference : For constant electric field, the equipotential surface are equidistant for same potential difference between surfaces; while for increasing electric field, the separation between these surfaces decreases, in the direction of increasing field, for the same potential difference between them.