Why is it the bird will not get electrocuted when holding on the live eletric wire?

Answer 1

Electrocution only occurs if the current can pass through and to the ground.

If the bird has one foot on the wire and one on the ground then bye bye birdie. Otherwise, it will be fine.

Answer 2

There are two reasons --

The first is that the wires used to transmit power are insulated. Electrical current cannot flow through the insulating material, usually some kind of plastic. They may furthermore be "armored", with a layer of metal braid or otherwise designed to protect the insulation from damage from, say, bird claws. Insulation is important on high-voltage lines to improve the reliability of the electrical transmission, to prevent several scenarios:

1) Wire breakage has less chance of causing electrocution and fires if the wires are insulated. If a broken wire falls on the ground and only the frayed end allows electricity to flow, this is less likely to touch something which can conduct electricity and catch fire or kill someone than if the whole length of the fallen wire can do that.

2) Less chance of short circuits from fallen tree branches which may touch more than one of the wires, and conduct electricty even more when wet.

3) Less "corona discharge". If a pointy object falls on the wire, even if it does not touch another wire, it can emit electrons, losing some power.

4) Less susceptibility to lightning strikes along the length of the wire.

If current cannot flow through the bird, it will be safe.

The second reason is that you need a complete circuit to flow current through the bird to cause it damage. Even if there’s no insulation, electricity cannot flow through the bird unless the bird is also touching another wire. "Bug-zappers" have closely-spaced uninsulated wire meshes where a bug can touch both one mesh at one voltage and another at another voltage, conduct electricity, and burn. One mesh is completely encircled by the other mesh, and if you touch just one, you don’t make a complete circuit and are safe. The outer mesh should have the same voltage as the ground, so that if you touch it and the ground, you still won’t conduct electricity. This reduces the hazards to humans who may blunder accidentally into one. It’s still not a good idea to touch them (or even go near when they are on).

Answer 3

It's not grounded. You need a ground to complete the circuit.

Answer 4

insulation