A power station delivers 440 kW of power through 3 ohm lines. How much power is wasted if it is delievered at 12000v?
The Attempt at a Solution
I believe you are supposed to solve it like this but I do not understand why:
I=P/V = 440000/12000=36.67 A
P lost =I^2R=(36.67)^2 (3) = 4033 W
But my gut instict tells me to do this which I believe is wrong from what I've read:
P=V^2/R = (12000)^2/3 = 4.8 x 10^7 W
P lost = P - Pused = (4.8 x 10^7 - 440000) =4.756 x 10^7W
I think I'm getting confused with what "V" is. I keep googling it and all I can tell is that I don't understand the different between voltage and voltage drop. I'm not clear what either is. Could anyone please explain?
Why does P=I^2R give you the power lost rather than the original power (440 kW) or the power used?