lhystérésis

Lhysteresis is a phenomenon observed in various physical systems where the output of a system depends not only on the current input but also on its past history. This means that the path taken by the system as the input changes can differ depending on whether the input is increasing or decreasing. The term "hysteresis" itself comes from the Greek word "hysteresis," meaning "lagging behind."

A classic example of hysteresis occurs in magnetism. When a ferromagnetic material is exposed to a magnetic field, it becomes magnetized. If the external magnetic field is then reduced, the material may retain some of its magnetization. This residual magnetism is a form of hysteresis. Similarly, the relationship between the applied magnetic field and the magnetization in a ferromagnetic material forms a hysteresis loop when plotted.

Hysteresis is also prevalent in other areas, such as the behavior of mechanical systems with friction, the electrical properties of certain materials like ferroelectrics, and even in biological systems. Understanding hysteresis is crucial for accurately modeling and predicting the behavior of these systems, as ignoring its effects can lead to significant inaccuracies. The presence of hysteresis often implies energy dissipation within the system.