Chapter 11

Direct Current Circuits

In Chapter 9, we learned that an electrostatic field cannot be sustained within a
conductor: The source charges move to the surface and the conductor forms a single
equipotential. We will now look at conductors within which an electric field can
be sustained because a power source maintains a potential difference across the
conductor, allowing charges to continually move through it. This ordered motion of
charge through a conductor is called electric current.