Question

Charges +q and -q are placed at points A and B respectively which are a distance 2L apart, C is the midpoint between,A and B. The work done in moving a charge +Q along the semicircle CRD is

Answer 1

Correct option (c)

Explanation:

Work done in moving charge +Q along the semicircle CRD is given by

Comments : Potential at C is zero because the charges are equal and opposite and the distances are the same.  Potential at D due to -q is greater than that at A (+q), because D is closer to B. Therefore it is negative.