Phasors: An ac source of period T and maximum voltage V is connected to a single unknown ideal element that is either a resistor, and inductor, or a capacitor. At time t = 0 the voltage is zero. At time t = T/4 the current in the unknown element is equal to zero, and at time t = T/2 the current is I = -I_max, where I_max is the current amplitude. What is the unknown element?

Question

Quizplus · Accepted Answer

The voltage leads the current by 90 degrees (T/4), which is characteristic of a capacitor in an AC circuit.

Phasors: an Ac Source of Period T and Maximum Voltage