Question

Why is alternating current used to distribute electricity?

Answer 1

Alternating current is important because it's voltage can be stepped up and down as required, thereby reducing power loss during transmission.

Explanation:

The value of alternating voltage can be altered in a transformer using desired number of turns in the secondary coil with respect to the primary coil.
According to law of conservation of energy, net energy is conserved and as voltage is stepped up, current is reduced since we have a relation `P=Vi`
We also know that, the energy dissipated in time t due to Joule's heating is,
`E=i^2Rt` thus, on reducing the current and increasing the voltage, the power loss is substantially reduced.
At the receiving station, the voltage is stepped down as much as we like.

PS : I copied it from another question I had answered.