Fundamentals of Engineering Electromagnetics 1st Edition by David Cheng

Exercise 52

A line charge of uniform charge density forms a circle of radius b that lies in the xy -plane in air with its center at the origin.
a) Find the electric field intensity E at the point (0, 0, h ).
b) At what value of h will E in part (a) be a maximum What is this maximum
c) Explain why E has a maximum at that location.