Equipotential Surface - Practice Questions & MCQ

A real or imaginary surface in an electric field that has the same potential at every point is called an equipotential surface.

Equipotential surfaces can be of any shape.

For example for a point charge of having charge q the potential at a distance, r is given as $V=\frac{k q}{r}$

So For V=constant, we get r=constant means for a point charge of having charge q, the equipotential surfaces are the concentric spherical surfaces having a charge q at their center as shown in the below figure.

All points on the spherical surface of radius r centered on q have the same V.

Properties of the equipotential surface-

• The potential difference between any two points on the Equipotential surfaces is zero.
• No work is done by the electric force to move the charge from one point to another point on an equipotential surface.
• Equipotential surfaces can never cross each other, otherwise potential at a point will have two values which is not possible.
• An equipotential surface is always perpendicular to electric lines of force.

          For example, An equipotential surface for a uniform electric field is shown below.

          From the figure, it is clear that the Direction of the electric field is perpendicular to the equipotential surface.