Hysteresis Loop

Hysteresis loop is the term commonly used in branch of science called physics. Hysteresis Loop shows relation between Magnetic Flux Density and Magnetizing Force as shown in above diagram. Hysteresis can be used  in sciences to filter signals. Hysteresis occurs when we repeatedly cycle the field up and down. We can say in other way that need of retraceability of the magnetization curve is the property called hysteresis and it is concerned with presence of magnetism in the material. Hysteresis phenomena occur in magnetic and ferromagnetic materials, as well as in the elastic and electromagnetic behavior of materials. When we magnetize a ferromagnetic material in a particular direction, there will be no zero magnetization when the applied magnetizing field is out. It must be equal to zero by a field in the reverse direction. If an alternating magnetic field is applied to the material, its magnetization will make  a loop which we call hysteresis loop.

Example, a device regulating temperature of system managing a electronic heater may turn the heater on when the temperature drops below X degrees, and keeping it on till the temperature rises above Y degrees.