The title describes my guesses as to what is happening in this problem, but I don't really understand it. Moderators, please do not delete this... I would give a non-dangerous example if I understood the problem well enough to actually know what the physics is. In class today, my physics professor, for a demo (please do not try this at home: it is dangerous!) plugged a pickle into an electrical outlet. It is a demo he does every year in his E&M class. The pickle starts on fire. Again, I did not do this, and will not do this, and you should not either. But it is what the professionally done demo was. What I do not understand is the following: he said that the end connected to the "hot" terminal of the outlet is the side on which the fire always starts. I do not understand why that should be, given that this is an alternating current source. Both sides are effectively exactly the same thing. My thought, then, is that this must have something to do with the fact that neutral is held at approximately ground potential, but I can't quite figure out how this works. Thanks!