Current Transmission in power lines

[siddharth5129]

If the electric field at a point drops off in intensity as the inverse ratio of the square of distance from the source, how do power lines manage to carry current through such large distances?

 

[Born2bwire]

Transmission lines are waveguides. They guide an electromagnetic wave that propagates the AC voltage signal. So instead of letting the energy radiate in all directions off in space (which gives rise to the 1/r^2 space loss), we direct its propagation along a desired path.

 

[astrokreng]

Power lines are able to carry current through large distances due to the use of transformers. Transformers are devices that can step up or step down the voltage of an electric current. This means that at the power plant, the voltage of the current is stepped up to a very high level, which reduces the amount of current needed to transmit the same amount of power. This high voltage current is then sent through the power lines, where it experiences a drop in intensity as it travels further away from the source. However, at the destination, the voltage is stepped down again, allowing the current to be used at a lower voltage but with the same amount of power. This process of stepping up and stepping down the voltage allows power lines to efficiently transmit current over large distances while minimizing energy losses. Additionally, power lines are also designed with materials that have low resistance, such as copper, which further helps to reduce energy losses during transmission.