Question

a bird sitting on a high tension wire does not receive an electric shock. why

Answer 1

because when two wire join together then shock is produce and in this case a bird is in one wire

Answer 2

There will be an electric shock if there is a potential difference established in your body,

When the bird sat on high tension wire, there won't be any potential difference established because both the legs are on the high tension wire,

This has been proven according to ohms law !

Hope you understand !!