The Faraday-Neumann-Lenz law, also known as Faraday’s law of induction or law of electromagnetic induction, is one of the basic principles of electromagnetism. It specifies how a magnetic field can interact with an electric circuit so that it can produce an electromotive force, that is, a phenomenon known as electromagnetic induction. It is considered as the basis of the operation of transformers, alternators, dynamos, inductors and other types of electric motors, generators and solenoids.
Michael Faraday can be attributed to the discovery of electromagnetic induction and the name of the law relating to this phenomenon, as proved by experiments by Faraday, although his explanation is limited to the concept of power lines.
The first formulation of Faraday’s law was made by Franz Ernst Neumann in 1845, in which the electromotive force generated in a circuit by induction should be expressed by the negative of the magnetic flux derivative over time by the area delimited by that circuit. The negative sign refers to the direction of the circuit and the electric current, which can be expressed through the so-called Lenz Law, developed by Heinrich Lenz in the year 1834.