Introduction to Electrodynamics · Problem 4.17

Electric Fields in Matter — David J. Griffiths

Physics · electric-displacement-bar-electret

Problem

For the bar electret of Prob. 4.11, make three careful sketches: one of

\mathbf{P}

, one of

\mathbf{E}

, and one of

\mathbf{D}

. Assume

L

is about

2a

. [Hint:

\mathbf{E}

lines terminate on charges;

\mathbf{D}

lines terminate on free charges.]