What term describes the induced emf that opposes the applied emf in an electric circuit?

The term that describes the induced emf which opposes the applied emf in an electric circuit is referred to as "back emf." This phenomenon primarily occurs in inductive components like coils and transformers, where a change in current induces an electromotive force that acts in the opposite direction to the current flow.

The concept can be understood through Lenz's Law, which states that the direction of induced current (and hence the induced emf) will always oppose the change in magnetic flux that produced it, thereby resisting the applied emf. This property is crucial in the operation of devices such as electric motors, where the back emf is a factor in limiting the current as the motor speeds up.

In contrast, forward emf, dynamic emf, and counter emf either do not specifically describe this opposing behavior or apply in different contexts or definitions that are not directly related to the opposing nature described in the question. Thus, back emf is the most appropriate term for this specific interaction in electric circuits.