Electromagnetic Induction

Producing a magnetic field by flowing current through a conductor is a process that can be reversed. A magnetic field can be set up that will cause current to flow in a conductor. This is called inducing or generating electricity by magnetism.

To induce voltage in a conductor it is necessary to have relative motion between the conductor and the magnetic field. This motion can be in any one of three forms:

• The conductor moves or rotates in a stationary magnetic field as in a DC Generator.
• The magnetic field rotates in a stationary conductor producing voltage in the circuit as in an AC Generator or Alternator.
• The building or collapsing of a magnetic field across a stationary conductor, as in an Ignition Coil.