What is the length of an iron wire with a cross-sectional area of 0.6 mm ^ 2 if, with a voltage at the ends of the wire of 12 V

What is the length of an iron wire with a cross-sectional area of 0.6 mm ^ 2 if, with a voltage at the ends of the wire of 12 V, the current in it is 2.5 A? Iron resistivity 0.1 Ohm mm ^ 2 | m.

To find the length of the indicated iron wire, we use the equality: U / I = R = ρzh * l / S, whence we express: l = S * U / (ρzh * I).
Variables and constants: S – cross-sectional area (S = 0.6 mm2); U – operating voltage (U = 12 V); ρzh – specific electrical resistance of iron (by condition ρzh = 0.1 Ohm * mm2 / m); I is the current in the wire (I = 2.5 A).
Calculation: l = S * U / (ρl * I) = 0.6 * 12 / (0.1 * 2.5) = 28.8 m.
Answer: The length of the indicated iron wire is 28.8 m.