Field of a Long Wire: Two Long Parallel Wires Carry

Multiple Choice

Field of a long wire: Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. What is the magnitude of the magnetic field midway between the two wires? (μ₀ = 4π × 10^-7 T ∙ m/A)

A) 1.0 × 10^-5 T
B) 2.0 × 10^-5 T
C) 3.0 × 10^-5 T
D) 4.0 × 10^-5 T
E) 5.0 × 10^-5 T