In the figure, what is the magnetic field at the point $O$
Medium
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(c) Magnetic field due to different parts are
$B_1 = 0$
${B_2} = \frac{{{\mu _0}}}{{4\pi }}.\frac{{\pi i}}{r}\odot$
${B_3} = \frac{{{\mu _0}}}{{4\pi }}.\frac{i}{r}\odot$
$\therefore \;{B_{net}} = {B_2} + {B_3} = \frac{{{\mu _0}i}}{{4r}} + \frac{{{\mu _0}i}}{{4\pi r}}$
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