Electrical engineers and electromechanical engineers work incessantly to develop motors, transformers, and transmission lines, that will save power by reducing eddy currents.
To greatly oversimplify, EDDY CURRENTS are "stray voltages" induced as part of the transmission and use of electromotive force.
Note how eddy currents form in this device.
Another loss we face is Hysteresis: stray voltage we develop in windings that can overheat motors, transformers, and transmission lines.
(Diagram courtesy Wikipedia.)
Rocmik you can google and copy and paste. I will give you that.