Suppose that there are two solid spheres with uniformly distributed charge throughout their volumes. Each has a radius R. The point P lies on a line connecting the centre of the spheres, with radial distance R/2 from the left sphere (sphere 1). If the net electric field is 0 at P, what is the ratio q2/q1 of the total charge q2 of sphere 2 to total charge q1 of sphere 1? (please explain in detail)
