Answer to Question #129598 in Mechanics | Relativity for Jacob

Question

When electric power is to be transmitted over long distances, is it economical to use high voltage and low current or low voltage and high current? Briefly explain your choice

Answer 1

When electric power is to be transmitted over great distances it is advantageous to use high voltage and low current. Heating loss in the line is proportional to the square of the current. Thus, the conductor size that is required to keep this loss to a desired fraction of total power transmitted decreases with the square of the current. Small conductors require less material. In addition, because they are lighter in weight, the cost of the supporting structures for overhead lines is correspondingly reduced.