Moving Charges And Magnetism

The current $I$ is flowing through a loop $A B C D A$ as shown in the figure. The magnitude of the magnetic field at the centre ' $O$ ' is $x$ times

\(\left(\frac{\mu_0 \mathrm{I}}{\mathrm{R}}\right)\left(\mathrm{OD}=\mathrm{R}, \mathrm{DC}=\mathrm{R}, \angle \mathrm{AOD}=90^{\circ}\right)\)

The value of ' $x$ ' is ( $\mu_0=$ permeability of free space)