Question

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 in units of 10^-5T?

Answer 1

here,

the current in first wire , I1 = 20 A

the current in second wire , I2 = 5 A

separation between wires , r = 0.2 m

the magnitude of magnetic field between the two wires , B = u0 * I1 /(2*pi*(r/2)) + u0 * I2 /(2*pi*(r/2))

B = 1.26 * 10^-6 /(pi*0.2) * ( 20 + 5) T

B = 5 * 10^-5 T

the magnitude of magnetic field between the two wires is 5 * 10^-5 T