A paramagnetic substance in the form of a cube with sides $1 \mathrm{~cm}$ has a magnetic dipole moment of…
A paramagnetic substance in the form of a cube with sides $1 \mathrm{~cm}$ has a magnetic dipole moment of $20 \times 10^{-6} \mathrm{~J} / \mathrm{T}$ when a magnetic intensity of $60 \times 10^{3} \mathrm{~A} / \mathrm{m}$ is applied. Its magnetic susceptibility is:
$3.3 \times 10^{-2}$
$4.3 \times 10^{-2}$
$2.3 \times 10^{-2}$
$3.3 \times 10^{-4}$
Solution
Magnetic susceptibility,
$\chi=\frac{\mathrm{I}}{\mathrm{H}}$
where, $\mathrm{I}=\frac{\text { Magnetic moment }}{\text { Volume }}=\frac{20 \times 10^{-6}}{10^{-6}}=20 \mathrm{~N} / \mathrm{m}^{2}$
Now , $\chi=\frac{20}{60 \times 10^{3}}=\frac{1}{3} \times 10^{-3}=3.3 \times 10^{-4}$