Long distance power transmission is carried on high voltage line. Why ?

Explanation

When current `I` is transmitted through a power line of resistance R, Power loss `= I^(2)R`.
If the power P is transmitted at voltage V, then
`P= VI or I = (P//V) :.` Power loss `= P^(2)/V^(2) R`
For a given power and given is line, P and R are constant. Hence, power loss `prop (1//V^(2))`
It means if power is transmitted at high voltage, power loss will be small and vice-versa.