Electric current is transmitted over a distance l = 600m along a two-wire line made of copper conductors with

Electric current is transmitted over a distance l = 600m along a two-wire line made of copper conductors with a cross-sectional area of S = 10mm2. the voltage at the beginning of the line is U0 = 240V, the current in the line is I = 18A. find the voltage at the end of the line and the voltage loss as a percentage of the nominal voltage Un = 220V.

Let us find the resistance R of two copper conductors, if their cross-section is S = 10 mm², and the length of each l = 600 m, the resistivity of copper p = 0.017 Ohm * mm² / m:
R = p * l / S = 0.017 * 2 * 600/2 * 10 = 1.02 Ohm.
Let us find the voltage drop Uп across the wires if the current strength I is 18 A:
Up = I * R = 18 * 1.02 = 18.36 V.
Let’s find the voltage U1 at the end of the line, if at the beginning of the line it was U0 equal to 240 V:
U1 = U0 – Uп = 240 – 18.6 = 221.4 V.
Let’s find the voltage loss in% of the nominal Uн, equal to 220 V:
Up% = Up * 100% / Un = 18.36 * 100/220 = 8.34%.
Answer: the voltage loss in the circuit was 8.34%.