Field and Wave Electromagnetics 2nd Edition by David Cheng

Exercise 92

Assume that the outer conductor of the cylindrical capacitor in Example 3-16 is grounded and that the inner conductor is maintained at a potential V 0.
a) Find the electric field intensity, E ( a ), at the surface of the inner conductor.
b) With the inner radius, b, of the outer conductor fixed, find a so that E ( a )is minimized.
c) Find this minimum E ( a ).
d) Determine the capacitance under the conditions of part (b).