
$\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{4 \pi \frac{\mathrm{d}}{\sqrt{2}}}\left(-\sin \frac{\pi}{4}+\sin \frac{\pi}{2}\right) \times 2 \otimes$
$\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \frac{\mathrm{d}}{\sqrt{2}}}\left(1-\frac{1}{\sqrt{2}}\right) \otimes$
$\mathrm{B}=\frac{\sqrt{2} \mu_{0} \mathrm{I}}{2 \pi \mathrm{d}}\left(\frac{\sqrt{2}-1}{\sqrt{2}}\right) \otimes$
$\therefore \mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{d}}(\sqrt{2}-1) \otimes$
$\mathrm{B}=\frac{\mu_{0} \mathrm{i}}{\sqrt{2} \pi \mathrm{d}}\left(1-\frac{1}{\sqrt{2}}\right) \otimes$


Reason : Moving charges produce only electric field in the surrounding space.