Electric motors

A wire carrying a current makes its own magnetic field, so in another magnet's field it is pushed sideways; reverse the current and it is pushed the other way. A simple motor is a rectangular coil that can turn on an axle between the north and south poles of a magnet: current flows one way along one side and the other way along the opposite side, so one side is pushed up and the other down, and the coil turns. A split ring, the commutator, reverses the current in the coil every half turn so it keeps turning the same way. More current, a stronger magnet or more turns make a stronger motor. A motor turns electrical energy into kinetic energy, with some lost as heat. Fans, coolers, washing machines, drills and electric cars all run on motors.