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? (u0 = 4pi × 10-7 T ∙ m/A)
A) 1.0 × 10-5 T B) 5.0 × 10-5** T C) 3.0 × 10-5 T D) 4.0 × 10-5 T E) 2.0 × 10-5 T
Answer is B please explain
