The magnetic field at a point $\mathrm{P}$ situated at perpendicular distance ' $R$ ' from a long straight wire carrying a current of $12 \mathrm{~A}$ is $3 imes 10^{-5} \mathrm{~Wb} / \mathrm{m}^2$. The value of ' $R$ ' in $\mathrm{mm}$ is $\left[\mu_0=4 \pi imes 10^{-7} \mathrm{~Wb} /…

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The magnetic field at a point $\mathrm{P}$ situated at perpendicular distance ' $R$ ' from a long straight wire carrying a current of $12 \mathrm{~A}$ is $3 	imes 10^{-5} \mathrm{~Wb} / \mathrm{m}^2$. The value of ' $R$ ' in $\mathrm{mm}$ is $\left[\mu_0=4 \pi 	imes 10^{-7} \mathrm{~Wb} / \mathrm{Am}ight]$

Aicharya · Accepted Answer

Using Biot-Savart's Law, $\begin{aligned} \mathrm{B} & =\frac{\mu_0 \mathrm{I}}{2 \pi \mathrm{R}} \ 	herefore \quad \mathrm{R} & =\frac{\mu_0 \mathrm{I}}{2 \pi \mathrm{B}} \ & =\frac{4 \pi 	imes 10^{-7} 	imes 12}{2 \pi 	imes 3 	imes 10^{-5}} \ & =8 	imes 10^{-2} \mathrm{~m} \ & =80 \mathrm{~mm} \end{aligned}$

The magnetic field at a point $\mathrm{P}$ situated at perpendicular distance ' $R$ ' from a long straight…

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