What does hysteresis in a magnetic context refer to?

Hysteresis in a magnetic context refers to the phenomenon where the output of a material depends not only on its current input but also on its past input. This is particularly evident in magnetic materials, where the magnetization of the material lags behind the applied magnetic field. When a magnetic field is applied to a material, it becomes magnetized, but when the field is removed, the material does not immediately return to its original state. Instead, it retains some magnetization due to the internal structure and arrangement of magnetic domains. This lag or delay in the response is what defines hysteresis.

The characteristic loop created when graphed demonstrates how the magnetic properties change during the application and removal of the magnetic field, illustrating that the material exhibits a certain history of magnetization. This behavior has significant implications in various applications, such as transformers and magnetic storage devices, where the efficiency and energy loss are critical considerations, highlighting why understanding hysteresis is essential for technicians in the field.