Electromagnetic Induction

Making Electricity (Also seen at GCSE Physics 3)

An e.m.f. can be induced across the ends of a conducting wire in two ways:

1) Move the wire through a magnetic field           or        2) Move a magnet through a coil of the wire

In both cases magnetic field lines and wires are cutting through each other. We say that the wire is cutting through the magnetic field lines (although it is fair to say that the field lines are cutting through the wire).

If the conductor is part of a complete circuit a current will be induced through it as well as an e.m.f. across it.

There are two laws that describe the induced e.m.f…

Faraday’s Law – Size of induced e.m.f.

The magnitude of the e.m.f. induced in a conductor equals the rate of change of flux linkages or the rate at which the conductor cuts a magnetic flux.