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
$\therefore {\chi }_m\alpha \frac{1}{T}$
$\frac{{\chi }_{m_1}}{{\chi }_{m_2}}=\frac{T_2}{T_1}=\frac{273+333}{273+30}=\frac{606}{303}=2$
$\therefore {\chi }_{m_2}={\chi }_{m_1}/2=0.5{\chi }_{m_1}$
$=0.5\chi \left(\because {\chi }_{m_1}=\chi \right)$