What term describes the induced voltage in a coil that opposes the original voltage?

The term that best describes the induced voltage in a coil that opposes the original voltage is "Counter or Back EMF." This phenomenon occurs due to Lenz's Law, which states that the direction of induced current is such that it opposes the change causing it. In the case of a coil or inductor, when the current flowing through the coil changes, a voltage is induced in the opposite direction to that of the original current. This opposing voltage is what is referred to as back electromotive force (Back EMF). It is an essential concept in understanding inductors and is particularly significant in electrical circuits where inductance plays a key role.