Question

Equipotential surface is a surface on which the electrical potential is the same at every point.

1. “Electric field lines are always parallel to Equipotential surfaces.” Correct the statement if there is any mistake.

2. Draw the equipotential for a single positive point charge.

3. A point charge +q is placed at the centre of a sphere of radius R. Another point charge +q is taken from a point A to another diametrically opposite point B on the surface of the sphere. Calculate the work done for this.

Answer 1

1. Electric field lines are always perpendicular to Equipotential surfaces.

2. Surface of the sphere is Equipotential in nature. So the potential difference between any points is zero. Since work done is the product of charge moving and the potential difference between the points, work done is equal to zero.