Question

a) Calculate the electrostatic force on a uniformly charged rod of length 2l,and charge q which lies along the axis of a uniformly charged ring of radius R and charge q'. The centers of the charged rod and the rings are displaced by z = z0 . (b) Show that if z0 >>l,is satisfied, then the expression of calculated force reduces to that between point charges.

Answer 1

Radius of the ring = R, length of rod = 2L and angle theta is the tangent to the circle the tangent distance is (4L^2 + R^2)^1/2 the equation of force is F = Q^2/4 pi epsilon (4L^2 + R^2) F = 2Q^2 L/4 pi epsilon (4L^2 + R^2)^3/2 Z_0 is the distance from the center of the charge of the rod then force will be F = Q^2 Z_0/4 pi epsilon (4L^2 + R^2)^3/2