Magnetic Circuit

—The path of magnetic flux in a magnetic substance or in electric or magnet ice apparatus. The greater part of such a circuit is usually in magnetic material, but there are often one or more air gaps included. The magneto-motive force may be supplied by coils of. wire carrying electric current or by permanent steel magnets. The law of the magnetic circuit is as follows: M Z in which, N is the magnetic flux, M, the magnetomotive force and Z, the reluctance.