A ring of radius a contains a charge q distributed. uniformly ober its length. Find the electric field at a point. on the axis of the ring at a distance x from the centre.

Explanation

`V_(P) = (1)/(4 pi in_(0)) .(Q)/(sqrt(R^(2) + x^(2))) = (Q)/( 4 pi in_(0)) .(R^(2) + x^(2))^((1)/(2))`
`E_(P) = -(del V_(P))/(del x) = - (dV_(P))/(dx)= -(Q)/(4 pi in_(0)) . (1)/(2) (R^(2) + x^(2))^(-(1)/(2) - 1) (2x)`
`= (1)/(4 pi in_(0)) (Qx)/((R^(2) + x^(2))^((3)/(2)))`