Two long parallel wires 0.1 m apart carry 5 A and 10 A in the same direction. The force per unit length on each wire is

1. The force per length between parallel currents is F/L = μ₀I₁I₂/(2πd). 2. Plug in: μ₀/(2π) = 2 × 10⁻⁷ T·m/A. 3. F/L = 2 × 10⁻⁷ × 5 × 10 / 0.1. 4. F/L = 10⁻⁴ N/m (attractive, since the currents are parallel). _Source: NCERT Class 12 Physics Ch 4 "Moving Charges and Magnetism", §4.9_