# Transmitted power

1. Sep 20, 2008

### goWlfpack

1. The problem statement, all variables and given/known data
A high-voltage transmission line with a resistance of 0.28 /km carries a current of 990 A. The line is at a potential of 740 kV at the power station and carries the current to a city located 162 km from the station.
(a) What is the power loss due to resistance in the line?
W

(b) What fraction of the transmitted power does this loss represent?
%

2. Relevant equations

Power= change in V^2/R

where v is potential difference and R is resistance

Power = I^2*R

where I is current

3. The attempt at a solution

I got part a correct. I used the equation p=I^2*R and got 44457336
I cant figure out how to get the second part though
I tried using p=v^2/R with 740,000 as the V and .28(162) as the R to no avail

any suggestions?

2. Sep 20, 2008

### Gear300

If you notice, V/R does not give a current of 990 A. The concept gets a little more complicated with a transformer. I*V (990A*740kV) is the provided power. I^2*R is the power lost to resistance.

3. Sep 20, 2008

### tiny-tim

Hi goWlfpack!
p = IV?

4. Sep 20, 2008

### goWlfpack

got it! thanks guys! :)