Question

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

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

Answer 1

Answer: (C)

$x \propto \frac{1}{T_C}$
curie law for paramagnetic substane
$\frac{x_1}{x_2} \, = \frac{T_{C_{2}}}{T_{C_{1}}}$
$\frac{2.8 \times 10^{-4}}{x_2} \, \, = \, \, \frac{300}{350}$
$x_2 \, \, \frac{2.8 \times 350 \times \, 10^{-4}}{300}$
$3.266 \times 10^{-4}$