Determine the voltage at the ends of a steel wire 140cm long and a cross-sectional area of 0.2mm2

Determine the voltage at the ends of a steel wire 140cm long and a cross-sectional area of 0.2mm2 through which a current of 250mA flows (steel resistivity 0.15Ohm * mm2 / m)

Initial data: l (steel wire length) = 140 cm = 1.4 m; S (cross-sectional area) = 0.2 mm2; I (the current that flows through the steel wire) = 250 mA (0.25 A).

Reference values: according to the condition ρ (resistivity of steel) = 0.15 Ohm * mm2 / m.

The voltage at the ends of the steel wire taken is expressed from the equality: R = U / I = ρ * l / S, whence U = ρ * l * I / S.

Calculation: U = 0.15 * 1.4 * 0.25 / 0.2 = 0.2625 V.

Answer: The voltage at the ends of the steel wire taken is 0.2625 V.