Maxwell’s equations and electromagnetism
In this appendix, we summarize some of the more advanced concepts in electromagnetism that are needed at various points in the book.
D.1 Polarization of a material
When we apply an electric field to a material, we pull on the electrons and, in the opposite direction, on the positively charged nuclei of the atoms. The resulting movement1 of the electrons and nuclei in response to this electric field is the polarization of the material.2
To be more precise in the definition of polarization, we should first discuss the idea of dipole moment. A typical way in which we view a dipole moment is to imagine that we have a pair of equal and opposite charges, of value +q and –q. We can separate them by ...