The distance between two parallel horizontal wires carrying the same current in opposite directions
The distance between two parallel horizontal wires carrying the same current in opposite directions is 20 cm. If the force between the wires per unit length is 1 x 10-4 Nm-1, calculate the current carried by the wires. Is the force between the wires attractive or repulsive? [μo = 4π x 10-7 NA-2]
The distance between two parallel horizontal wires carrying the same current in opposite directions is 20 cm. If the force between the wires per unit length is 1 x 10-4 Nm-1, calculate the current carried by the wires. Is the force between the wires attractive or repulsive? [μo = 4π x 10-7 NA-2]
The force per unit length between two long parallel wires is F/L = μ₀I²/(2πd).
So I² = (F/L) × 2πd/μ₀ = (1 × 10⁻⁴ × 2π × 0.2)/(4π × 10⁻⁷) = 100. Hence I = 10 A.
Currents in opposite directions make wires push apart, so the force is repulsive. The answer is 10 A, repulsive. Currents in the same direction would attract.
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