Question

At a temperatur of $30^{\circ }C$, the susceptibility of a ferromagnetic material is found to be $\chi$ . Its susceptibility at $333^{\circ }C$ is

• A. $\chi$
• B. 0.5$\chi$
• C. 2$\chi$
• D. 11.1 $\chi$

Answer 1

Answer: (B)

According to Curie's law, ${\chi }_m=\frac{{\mu }_{0}C}{T}$
where C is Curie constant, T = temperature
$\therefore {\chi }_m\alpha \frac{1}{T}$
$\frac{{\chi }_{m_1}}{{\chi }_{m_2}}=\frac{T_2}{T_1}=\frac{273+333}{273+30}=\frac{606}{303}=2$
$\therefore {\chi }_{m_2}={\chi }_{m_1}/2=0.5{\chi }_{m_1}=0.5\chi$
$\left(\because {\chi }_{m_1}=\chi \right)$