Physics - Modern Physics Question with Solution | TestHub

Magnetic field inside the cyclindrical conductor $B_{\text{in }}=\frac{{\mu }_0}{4\pi }\frac{2ir}{R^2}$ $(R=$ radius of cylinder and $r=$ distance of observation point from axis of cylinder) Magnetic field outside the cylinder at a distance $r^{\prime }$ from its axis, $B_{\text{out }}=\frac{{\mu }_0}{4\pi }\frac{2i}{r^{\prime }}$ $$\begin{array}{l}\Rightarrow \frac{B_{\mathrm{in}}}{B_{\mathrm{out}}}=\frac{r{r}^{\prime }}{R^2}\Rightarrow \frac{10}{B_{\mathrm{out}}}=\frac{\left(R-\frac{R}{4}\right)(R+4R)}{R^2}\\ \Rightarrow B_{\mathrm{out}}=\frac{8}{3}T\end{array}$$