electromagnetic induction

(electromagnetism) The production of an electromotive force either by motion of a conductor through a magnetic field so as to cut across the magnetic flux or by a change in the magnetic flux that threads a conductor. Also known as induction.

For more information on electromagnetic induction, visit Britannica.com.

The production of an electromotive force either by motion of a conductor through a magnetic field in such a manner as to cut across the magnetic flux or by a change in the magnetic flux that threads a conductor. See also Electromotive force (emf).

If the flux threading a coil is produced by a current in the coil, any change in that current will cause a change in flux, and thus there will be an induced emf while the current is changing. This process is called self-induction. The emf of self-induction is proportional to the rate of change of current.

The process by which an emf is induced in one circuit by a change of current in a neighboring circuit is called mutual induction. Flux produced by a current in a circuit A threads or links circuit B. When there is a change of current in circuit A, there is a change in the flux linking coil B, and an emf is induced in circuit B while the change is taking place. Transformers operate on the principle of mutual induction. See also Transformer.

The phenomenon of electromagnetic induction has a great many important applications in modern technology. See also Coupled circuits; Generator; Induction heating; Microphone; Motor; Servomechanism.

Production of an electric current by changing the magnetic field enclosed by an electrical circuit. The most common use of electromagnetic induction is in the electric generator.

Voltage produced in a coil due to relative motion between the coil and magnetic lines of force.