Question

The susceptibility of $Mg$ at $300K$ is $1.2\times {10}^{-5}$. The temperature at which susceptibility of $Mg$ will be $1.8\times {10}^{-5}$ is:

• A. $450K$
• B. $200K$
• C. $375K$
• D. None of these

Answer 1

Answer: (B)

$200K$

Here,

Magnesium is a paramagnetic substance and it follows,

$\chi =C\frac{{\mu }_0}{T}$

$i.e(\chi \times T)=\text{constant}$

In first case,

$\chi \times T=360\times {10}^{-5}$

In second case,

$360\times {10}^{-5}=1.8\times {10}^{-5}\times T$

$T=200K$

Option $\text{B}$ is the correct answer.