I think the main problem is the lack of proper terminology practice. I use the term to label the induced EMF of the higher value and reverse polarity than the voltage of the source inducing the original current flow (and thus magnetic field) that manifests itself when the conductance of the coil circuit goes suddenly to zero and the magnetic field collapses very fast. Now look at this very vague definition that is somewhat contradictory in itself Counter-electromotive force - Wikipedia, the free encyclopedia

When I think of it I cannot remember a proper term used in electronics. The phenomena is mostly labeled as detrimental as it might burn out the semiconductor devices (and thus all the protective snubber circuitry usually engineered in the circuitry) and simply calls it "transient phenomena". While that term is appropriate because it is transient phenomena it's at the same time very vague so no luck there. Just look at here Snubber - Wikipedia, the free encyclopedia In relation to the transil diodes it's only mentioned that they protect circuit from the "voltage spikes". Transient voltage suppression diode - Wikipedia, the free encyclopedia


So what would be the proper terminology for that fast transient phenomena?