Flashing Pendulum

The pendulum bob has a magnet at the end. On each swing, the magnet crosses a coil of copper wire assembly. The LED (light emitting diode) bulbs light up as the magnet passes the coil.
The exhibit demonstrates the phenomenon of inducing a current by changing the magnetic field in a coil of wire. This phenomenon called Electromagnetic Induction is the basis for the design of all electric generators.