Capacitors in AC The following diagram shows a circuit with an AC power source, a capacitor and a resistor with connections to the channels of an oscilloscope indicated. ' C '7 .1 0 Channel 1 Channel 3 F.' Given an AC current Ht) = Icosct) and source voltage VG) = Vcos{wt + $5) and that V05) 2 \"at\" + VR[t],the following relationship is found for the circuit above: Vcos[a1f+ (3.5) = 1; sinwt] + IRcos(wt) W1 It can be shown that the following relationship holds for the amplitudes of each term in the above: V3 = (f); + (IR)2