Answer to Question #189209 in Electric Circuits for Fakeomj

Question

Why are there at least two prongs on every electrical plug? If power is traveling in one direction (from the wall to the appliance), why can't there be just one wire carrying it? And don't just say "because circuits need to be closed' - after all, current can flow through a capacitor, and that's an open circuit.

Answer 1

Current is the rate of flow of charges (dq/dt). The charges flow from higher potential to lower potential. In the plug sockets one is the phase line with higher potential and the other is neutral line with lower potential (ideally zero potential) in case of AC circuits, In the case of DC circuits the scenario changes and it becomes positive to negative terminals. The charge carriers (electrons) flow from negative to positive which means the current flow from the positive terminal to the negative terminal.