Question

Need help asap /: Any would be greatly appreciated!(: Generating station uses 440-V transmission line to deliver 80 kW to a neighborhood. Resistance of the line is 20Ω. If the line was replaced to work at 12 kV, how much power would be required?

Answer 1

There is some problems here with this question, more than what the author intended. For the first situation. If it is intended for 440 volt generator to supply a 80 kW load with a transmission line having a resistance of 20 Ohm. There is no mention of the use of transformers etc. So the current needed to suppy the 80kW is (P=IE) is 181.181818 amperes this would mean a drop exceeding the supply voltage across the 20 resistance of the transmission line. In other words this scenario is similar to a short circuit.

Answer 2

With a 12 kV system supplying the 80Kw load, we would experience a current of 6 2/3 Amp which would produce 133 volt drop across the 20 Ohm. This is more realistic. And contrary to what is asked there is no additional power added, as the load remained at 80 kW or least the problem did not state that a larger load was added.