100kW of power is delivered to the other side of the city by a pair of power lines, between which the voltage is 12000V.
a) show that the current in the line is 8.3A
b) if each line has a resistance of 10 ohms show that there is a 83V change of voltage along each line.
c) show that the power expended as heat in both lines together is 1.38kW.
d) How do your calculations support the importance of stepping voltages up with transformers for long distance transmission.