Physics - Magnetism Question with Solution | TestHub

$\begin{array}{c}\text{Radial pieces: }B=0.\\ \text{Inner arc: into page}\\ B_2=\frac{{\mu }_{0}i}{2a}\\ \text{Outer arc: out of page}\\ B_4=\frac{{\mu }_{0}i}{6a}\\ B_{\perp }=B_2-B_4\\ B_{\perp }=\frac{{\mu }_{0}i}{3a}\\ \text{Straight pieces: downward}\\ B_{\parallel }=\frac{2{\mu }_{0}i}{3\pi a}\\ B_{\mathrm{net}}=\sqrt{B_{\perp }^2+B_{\parallel }^2}\\ B_{\mathrm{net}}=\frac{{\mu }_{0}i\sqrt{{\pi }^2+4}}{3\pi a}\\ \text{Option B}\end{array}$