Question

The magnetic susceptibility of a paramagnetic material at \( -73^\circ \text{C} \) is 0.0075. Its value at \( -173^\circ \text{C} \) will be:

• A. 0.00375
• B. 0.0150
• C. 0.0075
• D. 0.0300

Hint:

Magnetic susceptibility of paramagnets increases as temperature decreases.

Answer 1

The Correct Option is B

Step 1: Concept
According to Curie's Law, $\chi \propto 1/T$ (where $T$ is in Kelvin).
Step 2: Analysis
$T_{1} = -73 + 273 = 200 \text{ K}$. $T_{2} = -173 + 273 = 100 \text{ K}$. $\chi_{2}/\chi_{1} = T_{1}/T_{2} = 200/100 = 2$.
Step 3: Conclusion
$\chi_{2} = 2 \times 0.0075 = 0.0150$.
Final Answer: (B)