V is used to denote a voltage. E is used to denote electromotive force, which is, of course, a force expressed in units called volts. This leads many people to think that E and V are the same. Because they are.


A load does not draw current based on its need. It draws current based in its impedance at the moment. I say "at the moment" only to be picky-correct. Since loudspeakers, our putative loads here, do not present the same load at all frequencies, the load at any moment depends on the particular frequencies being played.