What term refers to the unwanted coupling of electric and magnetic fields?

The term electromagnetic interference (EMI) refers to the unwanted coupling of electric and magnetic fields, which can disrupt the normal operation of electronic devices and communication systems. EMI occurs when the electromagnetic fields from one device interfere with the signals of another, potentially causing issues such as poor performance or malfunction. This can arise from various sources, including motors, radios, and even low-quality cables.

In the context of the options provided, EMI is the most accurate choice, as it specifically addresses the interaction of electromagnetic fields that results in interference. Other terms like current, power loss, and signal degradation do not directly encompass the concept of unwanted coupling of electric and magnetic fields. Current refers to the flow of electric charge, power loss describes the decrease in power efficiency, and signal degradation pertains to the weakening or distortion of signals as they travel through a medium, but none of these terms specifically define the phenomenon of coupling between electric and magnetic fields as effectively as EMI does.