What term describes the residual magnetism in electronic devices?

The term that describes the residual magnetism in electronic devices is hysteresis. Hysteresis refers to the lag between the input and output of a system, particularly in magnetic contexts. When a magnetic material is exposed to an external magnetic field, it can become magnetized and retain some of that magnetism even after the external field is removed. This residual magnetism is a result of the physical alterations in the material's magnetic domains, which don't completely return to their original alignment. Hysteresis is critical in understanding the magnetic behavior of various electronic components, such as transformers and magnetic recording media, where the presence of residual magnetism can impact performance and efficiency.

In contrast, the other terms, while related to magnetism, do not specifically denote the concept of residual magnetism in the same way. For example, magnetic flux refers to the total magnetic field passing through a given area, induction pertains to the phenomenon where a change in magnetic field induces an electromotive force, and magnetic reluctance describes the opposition that a magnetic circuit presents to the magnetic flux, rather than the residual magnetism itself.