Draw an equipotential surface for a uniform electric field.

(N/A) For a uniform electric field,the electric field lines are parallel to each other and equally spaced.
An equipotential surface is defined as a surface where the electric potential is the same at every point.
For a uniform electric field directed along the $x$-axis,the equipotential surfaces are planes parallel to the $yz$-plane.
These planes are perpendicular to the direction of the electric field lines.
Thus,for a uniform electric field,the equipotential surfaces are a family of parallel planes.