Faraday's law This simulation shows the classic example of Faraday's law of electromagnetic induction. You will recall that in a closed circuit immersed in a magnetic field, an emf is induced if the magnetic flux through the surface enclosed by the circuit varies with time. Specifically, Faraday's law says that

By varying the orientation of the circuit relative to the field, thus varying Bperp . The simulation below illustrates the first two possibilities. The circuit consists of a U-shaped wire and a moveable wire free to slide on the legs of the U. The magnetic field is uniform and perpendicular to the circuit, but can vary with time. The sign conventions are: