Two identical point charges of +Q coul are separated by a distance of 10 cm. (a) Calculate the work done per unit change to bring up another charge from far

away along the perpendicular bisector of the line joining the two charges to

the point point midway between the charges.

(b)If one of the two charges in part(a) is changed from +Q to –Q, calculate the

work done per unit charge to bring up a charge to the same position as

above.