Electricity and Magnetism

Magnet + Electricity = Motor

This exhibit demonstrates the principles by which a motor functions. Closing a switch permits electricity to flow through the coils of wire wound around the motor shaft, called an armature. Holding a magnet around the coil causes the motor to turn. All motors operate for the same basic reason: When electricity flows through a wire and a magnet is nearby, the magnet exerts a force on the wire. Without either the magnet or the electricity, there is no "push" to make the motor turn. Turning the magnet over—reversing its magnetic field—reverses the "push" and causes an opposite rotation.