Determine magnitude of the electric field at the point P shown in the figure(Figure 1) . The two charges are separated by a distance of 2a. Point P is on the perpendicular bisector of the line joining the charges, a distance x from the midpoint between them.

Determine the direction of the electric field. Assume that the positive x and y axes are directed to the right and upward respectively.

 

+Q a a -Q P.