Now that we’ve seen how electric currents produce magnetism, and magnetism produce electricity, we can make electric motors and generators.
Kinetic energy of a waterfall or other energy source can be turned into electricity by a generator. The electricity can be transported by a copper wire to a distant location. An electric motor can in turn be set moving.
In the above circuit diagram, we have a generator consisting of a spinning magnet. This induces an alternating current into the live wire by sending electrons moving one way when the north pole of the magnet sweeps past the wire, and sending electrons moving the opposite direction when the south pole sweeps past the wire.
As long as the switch to the electric motor is open, nothing much happens. The electrons in the wire are pushed back and forth, but there’s no load on the generator. Very little energy is consumed.
However, once the switch is closed, electricity starts flowing past the magnet in the motor. The magnetic field induced by the free flow of electrons sets the magnet in the motor spinning.
The gaps between magnet and wire for both generator and motor are bridged by strong magnetic fields. The load on the motor is thus passed onto the generator.