Physics - Magnetism Question with Solution | TestHub

The magnetic field at P due to each wire is given by $B=\frac{{\mu }_{0}I}{2\pi r}$. Due to symmetry, the horizontal components cancel. The vertical components add up. Summing the contributions from all wires, considering alternating current directions, yields the net magnetic field.

$B_{net}=\frac{{\mu }_{0}I}{2\pi a}\frac{\ln 4}{\sqrt{3}}\hat{k}$