Question

The magnetic susceptibility of a paramagnetic material at $-73^{\circ }C$ is $0.0075$ and its value at $-173^{\circ }C$ will be

• A. 0.0045
• B. 0.0030
• C. 0.015
• D. 0.0075

Answer 1

Answer: (C)

Key concept Magnetic susceptibility measures the ability of a substance to take up magnetisation when placed in a magnetic field.
Given, $T_1=-73^{\circ }C=273-73=200K$
$T_2=-173^{\circ }C=-173+273=100K$
${\chi }_1=0.0075$
We know that, susceptibility of a magnetic substance,
$\chi \propto \frac{1}{T}$
So, $\frac{x_2}{x_1}=\frac{T_1}{T_2}$
$\frac{x_2}{x_1}=\frac{200}{100}$
$\frac{x_2}{0.0075}=\frac{2}{1}$
$x_2=2\times 0.0075=0.015$