Physics - Magnetism Question with Solution | TestHub

Magnetic field$\left(B\right)$at the centre of a coil of radius$\left(r\right)$carrying current$\left(i\right)$is

$B=\frac{{\mathrm{\mu }}_{0}i}{2r}$

$\Rightarrow i=\frac{2rB}{{\mathrm{\mu }}_0}$

Given,$B=0.5\times {10}^{-5} \mathrm{T},\mathrm{ }r=0.05 \mathrm{m}$

$i=\frac{2\times 0.5\times {10}^{-5}\times 0.05}{4\mathrm{\pi }\times {10}^{-7}}=0.398 \mathrm{A}$

$\Rightarrow i\approx 0.4 \mathrm{A}$