Problem 10: Two parallel wires 10 cm apart carry current of 8 A. What is the magnetic field half way between them?

Solution

Given data               r = 10/2 = 5 cm = .05 m              I₁ = I₂ = 8 A          B =?

Formula

Here μ₀ is the permeability of free space and its value is μ₀ = 4π * 10^-7 wb/A.m

Put these values to calculate magnetic fields due to both wires at the given distance.

Similarly the magnetic field due to the other wire

Under the given conditions of currents flowing in opposite directions, the magnetic fields due to both wires have same direction. Therefore, combined magnetic field at the given distance is