Potential and the Electric Field

Abstract

• To ensure the concepts and definitions of potential and potential difference are understood.

• To describe the potential gradient within a current-carrying conductor.

• To introduce the electric field as force on a charge and show that it is equivalent to the potential gradient.

• To develop the ideas of equipotential surfaces and field lines as illustrations of the field inside a current-carrying conductor.

• To relate electric field and current density with Ohm’s equation, to introduce charge mobility and to apply these ideas to photo-resistive devices.

• To extend the ideas of potential gradient and electric field from within a conductor into the space between conductors and to introduce the line integral.

• To show how equipotential surfaces lead to the concept of a conservative field and how this can be described using a loop integral.

• To show how electric fields can accelerate charged particles, and to apply this to gas-discharge tubes.