Faraday's Law of Induction

Faraday's law of induction states that a changing magnetic flux through a circuit induces an electromotive force in that circuit, with the magnitude of the induced electromotive force equal to the rate of change of the magnetic flux. English scientist Michael Faraday discovered the effect experimentally in 1831, finding that moving a magnet in and out of a coil of wire, or varying the current in one coil, could induce a current in a separate, unconnected coil. The law is often stated together with Lenz's law, formulated by Heinrich Lenz in 1834, which specifies that the induced current flows in the direction that opposes the change in magnetic flux that produced it, a consequence of the conservation of energy. Faraday's law is one of the four Maxwell's equations once James Clerk Maxwell incorporated it into his unified mathematical theory of electromagnetism in the 1860s, and the principle underlies the operation of electric generators, transformers, and induction motors.