Magnetic moment per unit volume (occasionally per unit mass), a vector quantity. Also called magnetic polarization or intensity of magnetization. Designated by symbols M or I. A measure of the effect of the medium on the magnetic field B when subject to a magnetizing force H:
where μo is the permeability of free space. The proportionality between magnetization and H is the magnetic susceptibility (q.v.), k or k′. See Figure M-1.