a secondary concept that is introduced for computations of static magnetic fields (by analogy with an electric charge, which creates an electrostatic field). Unlike electric charges, magnetic charges do not actually exist, because a magnetic field has no special sources other than electric currents.

The hypothesis of P. Dirac (1931) on the existence of magnetic charges (magnetic monopoles) in nature has not been confirmed experimentally, although attempts to detect them are continuing. For magnetized bodies the concepts of volume magnetic charge density pm and surface magnetic charge density can be introduced. The former is associated with the nonuniform distribution of magnetization throughout the volume of the body, and the latter, with the discontinuity in the normal component of magnetization on the surface of a magnetic material. Magnetic charges are located in double layers on the surface where the discontinuity in the normal component of the magnetization occurs, and the elementary magnetic charges of opposite signs are linked in magnetic dipoles.