Chapter 12

Magnetic Forces and Fields

In Chapter 9, we learned that electric charges are the source of electric fields and
that other charges experience an electric force in those fields. The charges
generating the field were assumed to be at rest. Electric charges that move are the
source of magnetic fields, and other charges that move can experience a magnetic
force in these fields. As you may recall, magnetic forces and fields make up a
significant portion of the SAT Physics Subject Test; they are the focus of this
chapter.