Electric motors use electromagnetic force to produce movement. Magnetic forces — attraction and repulsion — cause the electromagnet inside an electric motor to spin. Motors with metal brushes perform this function by creating opposite charges that attract and repel as the rotor changes polarity. A brushless electric motor relies instead on a solid-state controller to do the same thing.
In magnetic motors, magnetic fields form in both the rotor and the stator. These two fields give rise to a force, producing instantaneous torque on the motor shaft. These fields must be made to change with the rotation of the motor — otherwise it would abruptly stop. This is done by switching the poles on and off at the right time or varying the strength of the pole.
