Why is electricity sent oiver power transmission lines at very high potential differences?
Power is lost in a transmission line because the line has some resistance and inductance (which in this case, results in power being radiated as on a giant antenna). For example, the amount of power that is lost to resistance is a function of the square of the current traveling through the line and the resistance (P=I^2 * R). However, the amount of power received at the far end can be expressed in terms of P=I * V. Thus, if the voltage is increased to a very high level (100000+ V), the same amount of power can be delivered to the far end with much less current. Less current means lower transmission losses.
