Two charges 2 μC and -2 μC are placed at points A and B 6 cm apart. (a) Identify an equipotential surface of the system

Question

Two charges 2 μC and -2 μC are placed at points A and B 6 cm apart.
(a) Identify an equipotential surface of the system.
(b) What is the direction of the electric field at every point on this surface?

Answer 1

(a) For the given system of the two charges, the equipotential surface will be a plane normal to the line AB joining the two charges and passing through its mid-point O. At any point on this plane, the potential is zero.

(b) The electric field is in a direction from point A to point B i.e. From the positive charge to negative charge and normal to the equipotential surface.