A pure capacitor is connected to an ac power supply. In this circuit, the current
A) lags the voltage by $90 ^ { \circ }$.
B) leads the voltage by $90 ^ { \circ }$.
C) is in phase with the voltage.
D) lags the voltage by $180 ^ { \circ }$.
E) None of the given answers are correct.

Question

A pure capacitor is connected to an ac power supply. In this circuit, the current 
A) lags the voltage by $90 ^ { \circ }$.
B) leads the voltage by $90 ^ { \circ }$.
C) is in phase with the voltage.
D) lags the voltage by $180 ^ { \circ }$.
E) None of the given answers are correct.

Quizplus · Accepted Answer

In a purely capacitive circuit, the current leads the voltage by $90^\circ$. This is because the capacitor charges and discharges ahead of the voltage changes, causing the current to peak before the voltage does.

A Pure Capacitor Is Connected to an Ac Power Supply 90∘90 ^ { \circ }90∘

A Pure Capacitor Is Connected to an Ac Power Supply $90 ^ { \circ }$