The AC voltage across a pure inductance is said to __________.

In an AC circuit involving a pure inductor, the relationship between voltage and current is characterized by a phase difference. Specifically, the voltage across a pure inductance lags behind the current by 90 degrees. This means that when the current reaches its peak value, the voltage across the inductor is still increasing, and it does not reach its peak until a quarter cycle (90 degrees) later.

This lagging behavior occurs due to the inductive reactance, which resists changes in current. When the current changes direction, the inductor generates an opposing voltage due to its magnetic field, which in turn affects how the voltage relates to the current. This phase relationship is critical in understanding the behavior of AC circuits and is fundamental to the operation of devices that rely on inductive load.

Recognizing that the voltage lags rather than leads, remains in phase, or opposes current is essential for analyzing AC circuits and for predicting how inductors will behave within larger electrical systems.