# Electric Circuit Question

1. Nov 30, 2007

### CraZyBryaN

Hello. Hopefully someone here is able to answer this. I'm not sure if it's easy or hard, but it sure is frustrating... Here is the question...word for word, I would make a sad attempt at a picture, but it would probably be wrong. So...

"A powerhouse near a waterfall has a large DC generator that produces electricity for a factory 0.50 mile away. The energy is transmitted over two cables each with a resistance of 0.25 Ohms/Mile. Given that the factory requires 45kW at a voltage of 110V to run its equipment, what must be the output of the powerhouse"

We haven't talked a lot about resistances yet, so I think I'm probably making mistakes there...but yea. Thanks in advance.

2. Nov 30, 2007

### Staff: Mentor

For DC, power P = V * I, so I = P/V.

The total resistance over the line, R, is given by R = $\rho$ L, where $\rho$ is the resistance per unit length and L is the total length of the line.

Now what is the voltage drop and power loss over the line?