Consider a uniform electric field in the direction. The potential is a constant
a) in all space
b) on the x-y plane for a given z
c) for any y for a given z
d) for any x for a given z
The electric field in z-direction implies that equipotential surfaces are in x-y plane.
The answer is the option (b) on the x-y plane for a given z; (c) for any y for a given z; and (d) for any x for a given z.
The answer is the option (b)for any x for a given z; (c) for any y for a given z; and (d) for any x for a given z.