Question

The susceptibility of a magnetism at 300 K is \(1.2 \times 10^{-5}\). The temperature at which the susceptibility increases to \(1.8 \times 10^{-5}\) is:

• A. \(150\,\text{K}\)
• B. \(200\,\text{K}\)
• C. \(250\,\text{K}\)
• D. \(20\,\text{K}\)

Hint:

Paramagnetic susceptibility varies inversely with temperature.

Answer 1

The Correct Option is A

Step 1: Curie’s law: \[ \chi \propto \frac{1}{T} \]
Step 2: \[ \frac{\chi_1}{\chi_2} = \frac{T_2}{T_1} \Rightarrow \frac{1.2}{1.8} = \frac{T}{300} \]
Step 3: \[ T = 200\,\text{K} \]