Question

Find the magnetization of a bar magnet of length $10cm$ and cross-sectional area 4${cm}^2$ , if the magnetic moment is $2{Am}^2$

Answer 1

$M_{net}=2A{m}^2,I=10cm=10\times {10}^{-2}m$

Area of cross section = $4c{m}^2=4\times {10}^{-4}{m}^2$

Then,

Magnetization $\left(M_z\right)=\frac{M_{net}}{V}$ [V= l $\times$ cross-sectional area $V=10\times {10}^{-2}\times 4\times {10}^{-4}$ $V=4\times {10}^{-5}{m}^3]$

$\Rightarrow M_z=\frac{2}{4\times {10}^{-5}}$

$M_z=5000\frac{A}{m}$