I have been doing Barron's problems before I get to my good MCAT materials and I got a Physics Power problem that I was struggling with.
(1) Power station delivers 100kW at a voltage of 2.0kV. Transformer steps up voltage to 50kV. Assuming a line resistance of 50 ohms, what is power lost in transmission?
(2) Based on (1), what is power dissipated of 20kV transmission voltage?
The answer is 200W for the first one and 1.25kW(I think the units given in the book are wrong for this one) for the second one.
Now the explanation makes sense which is P=I^2*R after finding I from given power and voltage.
My question is since P=IV=I^2*R= V^2/R, why can't I directly do V^2/R to get power?
(1) Power station delivers 100kW at a voltage of 2.0kV. Transformer steps up voltage to 50kV. Assuming a line resistance of 50 ohms, what is power lost in transmission?
(2) Based on (1), what is power dissipated of 20kV transmission voltage?
The answer is 200W for the first one and 1.25kW(I think the units given in the book are wrong for this one) for the second one.
Now the explanation makes sense which is P=I^2*R after finding I from given power and voltage.
My question is since P=IV=I^2*R= V^2/R, why can't I directly do V^2/R to get power?
