Question

A circular loop of one turn carries a current of 5.00 A. If the magnetic field B at the centre is 0.200 mT, find the radius of the loop.

Answer 1

Here $n=1$

B at centre $O=\frac{{\mu }_{0}i}{2R}$

$\Rightarrow 0.2\times {10}^{-3}=\frac{4\pi \times {10}^{-7}\times S}{2R}$

$\Rightarrow R=1.57cm.$