Induced Electric Fields: Applications

An important distinction exists between the electric field induced by a changing magnetic field and the electrostatic field produced by a fixed charge distribution. Specifically, the induced electric field is nonconservative because it does not work in moving a charge over a closed path. In contrast, the electrostatic field is conservative and does no net work over a closed path. Hence, electric potential can be associated with the electrostatic field but not the induced field. The following equations represent the distinction between the two types of electric fields:

When the magnetic flux through a circuit changes, a nonconservative electric field is induced, which drives current through the circuit. However, when there is no conducting path in free space, it can be treated as if a conducting path were present; that is, nonconservative electric fields are induced wherever the magnetic flux through a circuit changes, whether or not a conducting path is present.