The phase difference between current and voltage in an AC circuit reveals the dominant component. This difference, measured in radians, clarifies the circuit's nature.
A current leading the voltage by \(\frac{\pi}{2}\) radians signifies a specific circuit behavior:
1. Purely Resistive Circuit: Current and voltage are in phase (\(\phi = 0\)).
2. Purely Inductive Circuit: Voltage leads current by \(\frac{\pi}{2}\) radians.
3. Purely Capacitive Circuit: Current leads voltage by \(\frac{\pi}{2}\) radians.
4. Resistance Equal to Reactance: This describes a resonant RLC circuit, where impedance is minimal. Phase differences here depend on component values and frequency.
Given that the current leads the voltage by \(\frac{\pi}{2}\) radians, the circuit is unequivocally purely capacitive.