# Power plant

Asmall power plant produces a voltage of 6.0kV and a current of 150A. The voltage is stepped up to 240kV by a transformer before being sent to a substation. The resistance of the transmission line between the power plant and the substation is 75 ohm. How much is the current flowing in the transmission line?

I(p)/I(s)= V(s)/V(p) s= stationary P= primary
V= IR

I(p) = 150 , V(p) = 6.0kV , V(s) = 240kV , I(s) = ?

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Redbelly98
Staff Emeritus
Homework Helper
I(p)/I(s)= V(s)/V(p) s= stationary P= primary

I(p) = 150 , V(p) = 6.0kV , V(s) = 240kV , I(s) = ?
Plug in the numbers and solve. V = IR is not needed here.

oh, why?
I don't know why V = IR is not needed here?

Redbelly98
Staff Emeritus
Homework Helper
It occurred to me (after discussing this with somebody else) that I may not understand the layout here.

Perhaps you have a figure you can look at to answer this question: is the 75 ohm line in between the power plant and the transformer, or is it between the transformer and the substation?

I think it is between the transformer and the substation.

Redbelly98
Staff Emeritus