Two long, parallel wires carry current in the x-y plane. One wire carries 30 A to the left along the x-axis. The other carries 50 A to the right along a parallel line at y = 0.28 m. At what y-axis position in meters is the magnetic field equal to zero?

Answer 1

μ₀I₁/2πy= μ₀I₂/2π(0.28-y)
I₁(0.28-y)= I₂y
30(0.28-y)=50y
80y=8.4
y=8.4/80=0.105 m