A 60 Hz single-phase source v (t) (shown below) is applied to a circuit element. For each circuit determine the current phasor I, the instantaneous current i(t), plot the voltage and current phasors and determine whether the current is in phase, leading or lagging the voltage.
v(t) = 392cos(\omega t + 30°)
(a) A 20 Ohms resistor
(b) A inductor of 3.77 Ohms
(c) A capacitor of 25 Ohms