Foucault's current

Foucault's currents are the electric currents intentionally or unintentionally induced in a flat conductor. It is a physical phenomenon that occurs when, for example, a changing magnetic field is in a metal plate. This could be an alternating field from an electric coil, but it could also be the result of movement that causes the plate to cut through the field lines. When a conductor cuts through magnetic field lines, a current is introduced in the conductor. 

For more information see eddy current on this page.