I understand that in an circuit with only an inductor, neglecting resistance, the applied AC voltage must, at all points in time, be infinitesimally greater and opposite to the induced emf for a steady current. My question is - since both the emfs are (almost) equal and opposite - is the net PD in the circuit constant (~0V neglecting resistance)? If it is, how is it that the current fluctuates? (i.e. shouldn't flow as a DC with a constant magnitude?) I know this might be a really simple question...but the teacher who was supposed to teach us chapter this decided not to (because of 'bad attendance').