In a uniform electric field directed along the Z-axis, the equipotential surfaces are parallel planes perpendicular to the Z-axis.

Explanation:

1. Uniform Electric Field: The field lines are straight and parallel along the Z-axis.
2. Equipotential Surfaces: These surfaces are always perpendicular to the direction of the electric field.
3. Resulting Shape: Since the field is uniform in the Z direction, the equipotential surfaces must be horizontal planes (parallel to the XY-plane).
4. Spacing of Surfaces: The potential difference between two equipotential surfaces is constant, so they are equally spaced along the Z-axis.

Diagram Representation:

The equipotential surfaces can be drawn as a series of horizontal planes (XY-planes) stacked at different Z-values, like this:

(z = V1)  ------------------  (higher potential)
(z = V2)  ------------------  
(z = V3)  ------------------  (lower potential)