Electromagnetic Induction

The core concept relies on magnetic flux, which is a measure of the total magnetic field passing through a given area. Faraday's breakthrough law states that whenever the magnetic flux linked with a closed circuit changes over time, an electromotive force (EMF), or voltage, is induced in the circuit. This change can be achieved by moving a magnet toward a coil, moving the coil itself, or changing the strength of the magnetic field.

The direction of this induced current is dictated by Lenz’s Law, a manifestation of the conservation of energy. It states that the induced current will always flow in such a way that its own magnetic field opposes the original change in flux that created it. EMI finds its most powerful application in AC generators, where mechanical energy is used to continuously rotate a coil inside a magnetic field, producing the alternating current that powers our homes and industries today.