In a purely inductive circuit, how does the current behave in relation to the applied source voltage?

In a purely inductive circuit, the current lags the applied source voltage due to the properties of inductance. Inductors resist changes in current flow, and as a result, when an AC voltage is applied, the magnetic field generated by the inductor takes time to build and collapse, causing a delay in the current flow.

This lag can be explained through the relationship between voltage and current in an inductor, typically represented mathematically as ( V = L \frac{di}{dt} ), where V is the voltage across the inductor, L is the inductance, and ( \frac{di}{dt} ) is the rate of change of current over time. As a result, when the voltage wave reaches its peak, the current wave reaches its peak after a certain time period, illustrating that the current lags behind the voltage.

The phase relationship can be represented visually on a voltage-current graph, where it’s clear that the peak of the current waveform occurs later than the peak of the voltage waveform. This important characteristic of inductive circuits is crucial for understanding AC circuit dynamics and plays a significant role in analyzing and designing electrical systems.