Ferromagnetic substances can be magnetized to saturation as long as they are under the action of a small magnetic field. Not only the magnetic susceptibility is >0, ond hefyd mae'r gwerth mor fawr â 10-106 gorchmynion maint. Mae'r berthynas rhwng y magnetization M a'r maes magnetig H yn swyddogaeth gymhleth aflinol. perthynas.
