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A current i ampere flows in a circular arc of wire whose radius is R, which subtend an angle $3\mathrm{\pi }}{2}$ radian at its centre. The magnetic induction B at the centre is

(a) $\frac{{\mu }_{0}i}{R}$

(b) $\frac{{\mathrm{\mu }}_{0}\mathrm{i}}{2\mathrm{R}}$

(c)$\frac{2{\mathrm{\mu }}_{0}\mathrm{i}}{\mathrm{R}}$

(d) $\frac{3{\mathrm{\mu }}_{0}\mathrm{i}}{8{\mathrm{R}}_{}}$