A magnetic field intensity at the centre of a circular wire of radius $0.1 \mathrm{~m}$ carrying a current…
A magnetic field intensity at the centre of a circular wire of radius $0.1 \mathrm{~m}$ carrying a current $0.2 \mathrm{~A}$ is
$2 \pi \times 10^{-5} \mathrm{~T}$
$\pi \times 10^{-7} \mathrm{~T}$
$10^{-7} \mathrm{~T}$
$4 \pi \times 10^{-7} \mathrm{~T}$
Solution
Magnetic field intensity at the centre of a circular wire $B=\frac{\mu_0 i}{2 r}=\frac{4 \pi \times 10^{-7} \times 0.2}{2 \times 0.1}=4 \pi \times 10^{-7} \mathrm{~T}$