| Ummm.... Essentially electrons must travel around in a circuit. Sort of like a racing car. Electrons can't teleport from one location to another, and the number of electrons in a circuit will never change. If touching you touch a wire, and you don't make a circuit (a complete loop) then you will receive no current (electrons can't move in a circuit), thus there is no voltage (since V = IR) Usually when you touch the active wires in a powerpoint a circuit is made: from the powerplant to the powerpoint,
from the powerpoint to you,
from you to the floor you are standing on,
from the floor back to the powerplant. A transformer works by having two coils of wires, and when electrons flow through one coil, it excites the electrons in the other coil, and they start to move too. (This is done through magnetism). A transformer is usually used to change the voltage of an AC source, but in the case of the "Isolation transformer" the voltage on the input side and the output side are the same. In a transformer, the two coils of wire aren't actually connected to each other. So if you touch one of the output wires, you don't make a circuit, as the electrons need to get back to the other output wire for a circuit to be formed. The same thing happens with a battery. Unless you are touching both terminals, there will be no current flow. |