Introduction to Electrodynamics · Problem 2.49

Electrostatics — David J. Griffiths

Physics · energy-sphere-nonuniform-charge

Problem

A sphere of radius

R

carries a charge density

\rho(r) = kr

(where

k

is a constant). Find the energy of the configuration. Check your answer by calculating it in at least two different ways.

[Answer: \pi k^2 R^7/7\epsilon_0]