A unit charge moves on an equipotential surface from a point A to point B, then

Draw an equipotential surface for a point charge.

Nature of equipotential surface for a point charge is

Nature of equipotential surface for a point charge is

Nature of equipotential surface for a point charge is

Draw equipotential surface for a point charge (Qlt0)

Sketch two equipotential surfaces for a point charge.

Show that for any charge configuration, equipotential surface through a point is normal to the electric filed at that point.