Important to inductors, transformers, generators, motors, magnetic fields, inductive heating, magnetic storage, permanent magnets

A changing electrical field produces a magnetic field. These magnetic fields can be used to store and transfer energy, as in an inductor or transformer. Proper mechanical application of the generated magnetic field can apply force or torque to create motion, as in a motor. Reverse application of the same principle can use mechanical action to generate electricity, as in a generator. Information can be stored in magnetic domains, as in a hard disk or magnetic tape.