A power stations output is 200mw and voltage of 25000volts what would be the current flowing out of the wires of the power station?

To work out the current flowing through the wires, you use a tree which is Power = Current times the voltages therefore Current is power divided by voltage

this is

0.2/25000 = 0.000008 amps

the reason for this is the higher the voltage the lower the current therefore less energy is lost as heat. which means more electricity reaches the step up transformers. :)


That looks suspiciously low. I think the questioner meant MW, not mW! (MegaWatts, not milliWatts)

So, assuming output power = 200MW instead and given a transmission voltage = 25kV.

Use indices to deal with all those 10s:

Power = 2 x 10^8 W and Volts = 2.5 X 10^4. (I wish you could use superscripts in Answers!).

Watts = Volts X Amps so I = W/V (The capital letter I, not A, is used to denote the ampere.)

=(2 x 10^8) / (2.5 X 10^4) = (2/2.5) X 10^(8-4) = 0.8 X 10^4 = 8 x 10^3

So a 200MW power-station is sending out a current of 8000A at a voltage of 25kV.


A quick test with a calculator - yes 8 000 X 25 000 = 20 000 000! Phew!

In practice I doubt very much that a power-station of anywhere near that rating would send all its output down one line. Also, I'm not sure, but its transmission voltage might be 250kV to divide the current by 10. 8kA is one hell of a current!