Engineering Physics

7.8 Hysteresis curve

Hysteresis means retardation or lagging of an effect behind the cause of the effect. In magnetism, hysteresis has been used between the applied magnetic field (H) and magnetization (M) of a magnetic material. Here, the effect is magnetization of a material and the cause of magnetization is the applied magnetic field. Usually, in magnetic materials, the magnetization of a material lags behind the applied magnetic field. This can be explained in detail, in the following way:

We start with an unmagnetized (M = 0) ferromagnetic specimen. With an increasing applied magnetic field on it, the magnetization of the specimen increases from zero to high values. The increase is non-linear. With small applied fields, the domains pointing ...