TABLE OF CONTENTS In Chapter 3 we were mainly concerned with the forces between charges at rest. In this chapter, we discuss the motion of charges in a conducting medium under the influence of electrostatic fields. More specifically, we will devote most of our attention to the motion of charges in a conductor when an electric field is maintained within the conductor.
We have already discussed that when an isolated conductor is placed in an electric field, the interior of the conductor remains a charge-free region and the charges rearrange themselves on the surfaces of the conductor. The electric field intensity within the isolated conductor vanishes when the conductor attains its electrostatic equilibrium.
Now suppose we suddenly deposit equal but opposite amounts of charged particles on the opposite ends of a conductor. The conductor loses its equilibrium, and an electric field is established within the conductor by these charges. The electric field forces these charges to move toward each other. As soon as the oppositely charged particles come in contact, they cancel. The process continues until all the charges disappear. When that happens the electric field within the conductor also disappears, and the conductor regains its equilibrium.
In this chapter, we intend to show that for conductors the approach to equilibrium is very fast. The time required for a good conductor to achieve equilibrium is a very small fraction of a second. During this very short time the charges rearrange themselves within the conductor. The motion of charges is said to...
