Consider a uniform electric field in the `hat (z)` direction. The potential is a constant.

Options

A. in all space
B. for any `x` for a given `z`
C. for any `y` for a given `z`
D. on the `x-y` plane for a given `z`.

Answer

B, C, D

Explanation

As electric field in the `hat(z)` direction is uniform, equipotentail surfaces are in `XY` plane. Hence the potential for given `z_(1)` is constant (i) on `x-y` plane (ii) for any `x` in this plane and (iii) for any `y` in this plane.
Hence Choics (b), (c), (d) are correct.