Question

A paramagnetic material has ${10}^{28}atoms/m^3$. Its magnetic susceptibility at temperature $350K$ is $2.8\times {10}^{-4}$. Its susceptibility at $300K$ is:

• A. $2.672\times {10}^{-4}$
• B. $3.726\times {10}^{-4}$
• C. $3.267\times {10}^{-4}$
• D. $3.672\times {10}^{-4}$

Answer 1

The correct option is C $3.267\times {10}^{-4}$

$X\propto \frac{1}{T_c}$
curie law for paramagnetic substane
$\frac{x_1}{x_2}=\frac{T_{c2}}{T_{c1}}$
$\frac{2.8\times {10}^{-4}}{x_2}=\frac{300}{350}$
$x_2=\frac{2.8\times 350\times {10}^{-4}}{300}$
$=3.266\times {10}^{-4}$