Task id16540

It is required to transmit electrical energy over a distance l = 10 km using copper wires so that the energy loss in the wires does not exceed 10%. Power plant power N = 100 kW. Voltage at the power station U1 = 220 V. Find the mass of copper required for the wires. How much copper will be required at voltage U2 = 440 V? The resistivity of copper is p = 0.017 μOhm m, its density is y = 8.9 103 kg/m3.