You often see small birds perching on power lines. They mistakenly think electric wires are ordinary tree branches. They often park in groups on electric wires, especially on medium and high voltage power lines, but do not get electrocuted.
Why is this so when if we accidentally touch an exposed electric wire, we will be shocked and can even die. Because birds wear insulated shoes, they don’t get shocked when they land on electric wires? Not so.
Electric current is the movement of electrons through a wire. It always takes the easiest path, that is, always finds the path of least resistance to run through.
The difference in resistance is the main reason why birds do not get shocked when perched on electric wires.
Electrical transmission cables are usually made of copper. Copper has the lowest resistivity and is a very good conductor of electricity.
Meanwhile, the bird’s body has a higher resistivity and is a much poorer conductor than copper. Therefore, the electric current will bypass the bird’s body and pass through the power cable. As a result, the bird is not shocked.
Besides, current flows from the place of highest potential to the place of lowest potential. Electrical cables often have different voltages. If a bird’s two legs are placed on the same cable, they have the same potential. Therefore, the bird is not shocked.
However, if the bird is placed on two different cables (with different voltages), current will pass through the bird’s body from the high voltage cable to the lower voltage cable, causing the bird to be electrocuted.
As for us standing on the ground, our body in contact with the positive wire of the electric wire will form an electric circuit, the electric current will flow from the body to the ground, causing an electric shock.
If we wear rubber-soled shoes with good insulating properties or stand on an insulated wooden chair, even if we touch the positive wire, we will not be electrocuted. Your state at that time is similar to a bird sitting on an electric wire. Some professional electricians who understand this principle can do this when connecting electricity.