Two parallel wires 0.1 m apart carry currents of 10 A each in opposite directions. The force per unit length on one wire is (μ₀ = 4π × 10⁻⁷ T·m/A):
Correct answer: A. 2 × 10⁻⁴ N/m
- A. 2 × 10⁻⁴ N/m
- B. 4 × 10⁻⁴ N/m
- C. 1 × 10⁻⁴ N/m
- D. 8 × 10⁻⁴ N/m
Explanation
Force per unit length between parallel wires is F/L = (μ₀I₁I₂)/(2πd). Substituting μ₀ = 4π × 10⁻⁷, I₁ = I₂ = 10 A, d = 0.1 m: F/L = (4π × 10⁻⁷ × 10 × 10)/(2π × 0.1) = 2 × 10⁻⁴ N/m.
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