When the power supply in a circuit is a DC battery (providing a constant potential difference ΔV, capacitors and inductors cause a quasi-steady state current where the current is different at different times (either exponentially increasing or decreasing). If the same circuit is connected to an AC power supply (where ΔV=ΔV max cos(at) with ΔVmax being the maximum potential) the current will generally exhibit a phase shift (1-Imax cos(at ± g), which is a different manifestation of the same physics principles at work in the DC circuit case.

For each situation, indicate the correct choice. (You can assume that the initial transient charging of the circuit has passed. Thus the circuit is in either quasi-steady state or steady state.)

(a) a circuit with a battery and a resistor

A. current is constant with time
B. current is exponentially increasing or decreasing with time
C. current is oscillating with no phase shift (φ = 0)
D. current is oscillating with a phase shift (φ 0)