Question

Figure shows, in cross section , two solid spheres with uniformly distributed charge throughout their volumes. Each has radius R. Point O lies on a line connecting the centers of the spheres, at radial distance `R//2` from the center of sphere 1. If the net electric field at point P is zero, and `Q_1 is 64muC` and `Q_2 = 8xmuC`, what is the value of x.

Answer 1

`E_(P)=(kQ_(2))/(((3R)/(2))^(2))-(kQ_(1)(R)/(2))/(R^(3))=0`
or `(4)/(9)Q_(2)=(Q_(1))/(2)` or `(Q_(2))/(Q_(1))=(9)/(8)`
`thereforeQ_(2)=(9xx64)/(8)=72muC=8xx9muC`