Why We Step Up Voltage for Long-Distance Power Transmissions

[gubretaw]

I have an assignment that requires me to discuss why do we step up voltage when transmitting power over long distance.

I was told that in having a high voltage you have a low current, which then reduces the power loss. What I do not understand is how does low current relates to the reduction in power loss?

 

[Hootenanny]

The resistance of a conductor converts electric energy into heat energy (via the collisions of the electrons with the metal lattice). If we use $P = IV$ and $V = IR$ we can show that the power dissapated by the resistance is given $P = I^{2}R$. Therefore, lowering the current, reduces the power loss.

~H

 

[siddharth]

Adding to what Hootenanny said, you might also want to visit this site.
http://www.bsharp.org/physics/stuff/xmission.html"