Why does Ac current travel longer than Dc?

Answer 1

DC cannot travel very far until it begin to lose energy,but AC can be made high or low by "Transformers".DC can also be transformed but it is a bit difficult than transforminf AC.AC transmission loses less energy because as current altenates the loss is reduced i.e when voltage is at +peak more loss and at -ve peak loss is less.in this way the loss is less in AC transmission.

Answer 2

The fact that it is alternating. AC means Alternating Current. DC means Direct Current.

Alternating current means that the voltage increases, then decreases, then changes polarity and increases, then back to zero. The change in voltage like this normally follows a sinusoidal wave form (or sine wave).

AC Current can be made simply by rotating magnetic field inside a coil. This is the basis of an electrical generator called an Alternator.

As the North and South poles pass over the coil, in a rotary motion, it can be seen how the output from the coil will vary as suggested above.

It is actually harder to make DC current from a rotating electrical generator. The magnetic field has to be interrupted and started again using several coil windings. This requires a rotating switch called a commutator, and carbon brushes. (which spark and wear out).

DC current is more commonly made by a chemical reaction, such as a battery. The polarity does not change on the terminals and as long as there are active chemicals, a potential difference is provided.

Inverters can be used to convert DC to AC. By using electronics a DC current can be turned into an AC current (mimicking an alternator), using oscillators and switching transistors.