A generating station is producing 1.0 106 W of power that is to be sent to a small town located 6.0 km away. Each of the two wires that comprise the transmission line has a resistance per kilometer of length of 5.0 10-2 /km.
(a) Find the power lost in heating the wires if the power is transmitted at 1050 V.
(b) A 100:1 step-up transformer is used to raise the voltage before the power is transmitted. How much power is now lost in heating the wires?
2007-03-24 05:53:02 · 1 answers · asked by madison c 1 in Science & Mathematics ➔ Physics
The loop resistance of the transmission line is
2*6 km * 5E-2 ohms/km=0.6 ohms
the current through the line at 1050 v is 1E6/1050=952.4 A
The I^2R losses are 0.6*(952.4)^2=544.2 KW
at 100x voltage the current will by 100 times less or 9.52 A
the I^2R losses are now (9.52)^2*0.6=54.4 W
2007-03-24 13:21:45 · answer #1 · answered by Rob M 4 · 0⤊ 0⤋