Determine the voltage at the ends of an iron conductor with a length of 150 cm and a cross-sectional area of 0.025 mm2

Determine the voltage at the ends of an iron conductor with a length of 150 cm and a cross-sectional area of 0.025 mm2, in which the current strength is 250 mA, and the resistivity is p = 0.1 Ohm * mm2 / m.

L = 150cm = 1.5m.

S = 0.025 mm2.

I = 250 mA = 0.25 A.

ρ = 0.1 Ohm * mm2 / m.

U -?

According to Ohm’s law for a section of a circuit, the voltage at the ends of the conductor U is equal to the product of the current in the conductor I by its resistance R: U = I * R.

Since the conductor is homogeneous and has a cylindrical shape, its resistance R is expressed by the formula: R = ρ * L / S, where ρ is the resistivity of the material from which the conductor is made, L is the length of the conductor, S is the cross-sectional area of ​​the conductor.

U = I * ρ * L / S.

U = 0.25 A * 0.1 Ohm * mm2 / m * 1.5 m / 0.025 mm2 = 1.5 V.

Answer: at the ends of the iron conductor, the voltage is U = 1.5 V.