What do we call induced voltage that moves in the opposite direction as applied voltage in an inductor?

The term used to describe the induced voltage that moves in the opposite direction to the applied voltage in an inductor is known as counter electromotive force (EMF). This phenomenon occurs due to Lenz's Law, which states that the direction of induced current (and therefore the induced voltage) will always oppose the change in current that created it.

In practical terms, when the current in an inductor changes, it generates a magnetic field that, as it collapses or builds up, induces a voltage in a direction opposite to the applied voltage. This reaction helps resist changes in current and contributes to maintaining stability in electrical circuits, highlighting the inductor's role in energy storage and management in inductive components.

Inductive reactance refers to the opposition that inductors offer to the change in current, but it does not specifically describe the induced voltage itself. Electromagnetic interference pertains to external electromagnetic disturbances affecting electronic equipment, while back current generally refers to a current that flows in the reverse direction but does not encapsulate the specific concept of induced opposite voltage as counter EMF does. Hence, counter electromotive force is the most accurate term to capture this behavior in inductors.