Electromagnetic induction is the production of an electromotive force across a conductor when it is exposed to a varying magnetic field. It is described mathematically by Faraday's law of induction, named after Michael Faraday who is generally credited with the discovery of induction in 1831.
Electromagnetic induction was discovered independently by Michael Faraday and Joseph Henry in 1831; however, Faraday was the first to publish the results of his experiments.[4][5] In Faraday's first experimental demonstration of electromagnetic induction (August 29, 1831[6]), he wrapped two wires around opposite sides of an iron ring or "torus" (an arrangement similar to a modern toroidal transformer). Based on his assessment of recently discovered properties of electromagnets, he expected that when current started to flow in one wire, a sort of wave would travel through the ring and cause some electrical effect on the opposite side. He plugged one wire into agalvanometer, and watched it as he connected the other wire to a battery. Indeed, he saw a transient current (which he called a "wave of electricity") when he connected the wire to the battery, and another when he disconnected it.[7] This induction was due to the change in magnetic flux that occurred when the battery was connected and disconnected.
STATEMENT
The induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic fluxthrough the circuit.
The law of physics describing the process of electromagnetic induction is known as Faraday's law of induction and the most widespread version of this law states that the induced electromotive force in any closed circuit is equal to the rate of changeof the magnetic flux through the circuit. Or mathematically,
,
where is the electromotive force (EMF) and ΦB is the magnetic flux. The direction of the electromotive force is given byLenz's law. This version of Faraday's law strictly holds