Electromagnetic induction is the creation of an electro-motive force (EMF) by way of a moving magnetic field around an electric conductor and, conversely, the creation of current by moving an electric conductor through a static magnetic field. Electromagnetic interference (EMI) is also known as electric current and electromagnetic induction and may also be called magnetic induction, as the principle remains the same whether the process is carried out through electromagnet or static magnet.
Electromagnetic induction was discovered by Michael Faraday in 1831 and, independently and almost simultaneously, by Joseph Henry in 1832. Faraday discovered electromagnetic induction and demonstrated it with a copper coil around a toroidal piece of iron, a galvanometer (a gauge-based device to show current) and a magnet. When the magnet was moved towards the coil, an EMF is created moving the gauge on the galvanometer. If it is the north end of the magnet that is drawn closer, current flows one way; if the south is drawn closer, then current flows in the opposite direction.
The discovery of electromagnetic induction was a fundamental principle in understanding and harnessing electricity. James Clerk Maxwell formulated the mathematical description as Faraday’s Law of induction, later known as the Maxwell-Faraday Equation.
The principle of electromagnetic induction is used in electronic components such as inductors and transformers. Electromagnetic induction is the basis of all types of electric generators and motors used to generate electricity from motion and motion from electricity.