Human Generator

The Demonstration: Students turn a crank to generate electricity and light up a bulb.

The Physics:

The human generator is very similar to an emergency generator you may have at your home or school. In order to make electrons move through a circuit, they must receive a push. This usually comes from a battery or electrical socket. But when the lights go out, we need another way to generate electricity.  When you turn the crank, you are turning a magnet and causing a magnetic field to spin around. The changing magnetic field pushes the electrons around and creates a current in the wires. The human generator is kind of like the opposite of an electromagnet, which uses electricity to make a magnet; the generator uses a magnet to create electricity. As you turn the crank, you are turning a magnet that pushes on the electrons. An emergency generator also has an electromagnet that spins to create electricity. Electricity can also be generated from other forms of motion such as windmills and hydroelectric plants.