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) $