In its simplest terms, electromagnetic induction can be defined as the process where a conductor placed in a changing magnetic field causes the production of voltage across the conductor. This, in turn, causes or ‘induces’ an electric current.
Many electrical devices that we see daily work on the principle of electromagnetic induction. A common use of this can be seen in electrical generators, transformers, induction cookers, musical instruments etc. The concept of electromagnetic induction was put forth in the early 1830s by the English physicist Michael Faraday.
He conducted many experiments to study the idea. In one of it, he used a coil of wire, a permanent magnet and a device to detect voltage in the wire. When Faraday passed the magnet through the coil of wire, he saw there was a voltage induced and therefore current too. But it soon disappeared when the magnet stopped moving. From this, Faraday made a few observations. The most important one was that the induced voltage is the result of a changing magnetic field.
In other words, Faraday discovered a way to produce electrical current by using the force of a magnetic field.
The voltage induced is known as the electromotive force, or emf.
Faraday’s findings led to a law linking electricity and magnetism known as the Faraday’s Law of Electromagnetic Induction.