The current density of a nickel-plated conductor with a length of 25 m is equal to 1MA / m2.

The current density of a nickel-plated conductor with a length of 25 m is equal to 1MA / m2. Determine the potential difference at the ends of the conductor.

Initial data: l (length of nickel conductor) = 25 m; j (given current density in the conductor) = 1 MA / m2 (1 * 10 ^ 6 A / m2).

Reference data: ρ (specific resistance of nickel, 20 ºС) = 0.4 Ohm * mm2 / m = 0.4 * 10 ^ -6 Ohm * m2 / m.

We express the potential difference at the ends of the nickelin conductor from the formula for calculating the current density: j = I / S = (φ1 – φ2) / (R * S) = (φ1 – φ2) / ((ρ * l / S) * S) = (φ1 – φ2) / (ρ * l), whence φ1 – φ2 = j * ρ * l.

Calculation: φ1 – φ2 = 1 * 10 ^ 6 * 0.4 * 10 ^ -6 * 25 = 10 V.