why using high voltage transmission can reduced the resistance?please give me a clear explanation...
2007-07-21 16:26:58 · 3 answers · asked by Daireen 2 in Science & Mathematics ➔ Physics
here's 2 links that could help u .. If u have more questions or comments please let me know ..
u r welcome any time to ask whatever..
2007-07-21 16:46:42 · answer #1 · answered by M. Abuhelwa 5 · 0⤊ 1⤋
hello Sh....
High voltge cannot reduce resistance in a conductor.Resistance is a mechanical property of a conductor and can only be reduced by supercooling.Lets dust off ohms law ..P=I x E ......P=watts I = amps and E = volts....... lets solve for I (amps) ... .I= P/E just for fun lets give P a value of 10000(watts) and E a value of 250(volts)...that comes out to around 40amps ...to do a forty amp job you need a wire sized about #10 awg .......now lets change only the voltage 10000watts / 1240volts . Well when you divide that out it gets your wire size down to #14 awg ....
In transmission work we use 138kv and up this reduces wire size considerabley... and oh yea to set the record straight the real formula for 3 phase is P= I(amps)x E(volt) x (sq root of 3 =1.732) so you even get a better savings in wire size...For fun Look for the K value of copper its in the code book....Good luck from the E!!!!!
2007-07-21 23:51:10 · answer #2 · answered by Edesigner 6 · 0⤊ 0⤋
It doesn't reduce the resistance, the resistance is fixed by the length and size of the copper cables that make up the line. By Ohm's Law I=V/R, and the power transmitted down the line is IV, so if you want more power transmitted you have no choice but to increase the voltage.
2007-07-21 23:47:23 · answer #3 · answered by pegminer 7 · 2⤊ 0⤋