In our house most of the plug-points have 2 holes. I know that one hole is neutral and other one supplies electricity. I can say that when i plug any device and turn the switch on electricity starts to flow which also means that electrons flow through my device and make the device work. If we think about a simple circuit we see that electrons or current flows through a bulb or whatever and goes to battery or to the power source. Now my question is , where do the electrons or current go after passing through my device in plug-points ? I know they go through the neutral hole but where do they go through neutral hole ? Do they go to the earth ? Or they go the power stations from where electricity is coming(?)
The neutral hole as you call it is actually a ground that connects to the body of the appliance being used. In the good old days refrigerators, for example, might develop a short between the internal circuitry powered by a 2-prong plug - by placing a second ground wire in the system which connected to the body of the appliance this "shocking" capability was averted. The outlets in many old homes may still have only two receptacles of similar size to match appliance plugs which could be inserted in either direction...the three pronged plugs averted that problem. Current two position plugs are not bi-directional with the ground side being larger. In wiring house receptacles the black wire (think of funeral colors) is "hot", the white wire goes to ground (large insert on left) and the bare copper wire goes to neutral and may be connected to the white wires in the circuit box. The electron flow is actually from the ground to what is considered the positive or hot side. In civilian electronics the red wire is hot and the black wire is ground. Edison got the electron flow backwards which prevented him from inventing the transistor...the military version is correct.