Question

An AC power generator produces 48 A (rms) at 3,600 V. The voltage is stepped up to 100,000 V by an ideal transformer, and the energy is transmitted through a long-distance power line that has a resistance of 146 Ω. What percentage of the power delivered by the generator is dissipated as heat in the power line? %

Answer 1

P = V X i

P = 3600 X 48

P = 172800 W

then i = 172800 / 100000

i = 1.728 A

using Ohm's Law

V = i X R

V = 1.728 X 146

V = 252.288 volts

the dissipation is = 252.288 X 1.728

= 435.95 W

the percentage of loss = 435.95 X 100 / 172800

the percentage of loss = 0.252 %

the percentage of the power delivered by the generator is dissipated as heat in the power line is = 0.252 %