The welding machine is connected to the network with copper wires 100 m long and a cross-sectional area of 50 mm2.

The welding machine is connected to the network with copper wires 100 m long and a cross-sectional area of 50 mm2. Determine the voltage on the wires if the current strength in them is 125A.

Data: l (length of copper wires used) = 100 m; S (cross-sectional area of wires) = 50 mm2; I (current) = 125 A.

Constants: ρ (electrical resistivity of copper) = 0.017 Ohm * mm2 / m.

1) Resistance of the wires used: R = ρ * l / S = 0.017 * 100/50 = 0.034 Ohm.

2) Voltage on wires: U = I * R = 125 * 0.034 = 4.25 V.

Answer: The voltage across the copper wires used is 4.25 V.