# Field is not zero

**Electricity and Magnetism**Level pending

A point charge \(q\) is located at the center of a thin ring of radius \(r\) with uniformly distributed charge \(-q\). Find the magnitude of the electric field strength vector at the point lying on the axis of the ring at distance \(x\) from its center with \(x >> r\).

If the answer is in the form of \( \frac {aq r^b}{c\pi} \epsilon(x^d) \) for positive integers \(a,b,c,d\) with \(a\) and \(c\) coprime, give your answer as \(a+b+c+d\).