Faraday's law of electromagnetic induction is used to calculate the EMF (electromotive force) that will be generated by the movement of a conductor through a magnetic field.

It states that ε, the induced EMF, is equal to


where Φ is the amount of magnetic flux linkage in the field, and t is time.

Δ, delta, means change, so the equation states that the magnitude of the induced EMF is equal to the rate of change of magnetic flux linkage.

It is significant that the magnitude of the EMF does not depend directly on how strong the magnetic field is, but on how quickly the level of flux surrounding the conductor is changing.