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.