Question

Using Langevin's theory, the susceptibility \( \chi \) of a paramagnetic substance is given by:

• A. \( \chi = \frac{m^2 N \mu_0}{3kT} \)
• B. \( \chi = \frac{m^2 \mu_0}{3kT} \)
• C. \( \chi = \frac{m^2 N \mu_0 T}{k} \)
• D. \( \chi = \frac{m^2 N \mu_0}{2kT} \)

Answer 1

The Correct Option is A

Using Langevin's theory, the susceptibility \( \chi \) of a paramagnetic substance is related to the magnetic moment \( m \), the number of molecules \( N \), the permeability of free space \( \mu_0 \), the Boltzmann constant \( k \), and the temperature \( T \). The correct formula is:

\[ \chi = \frac{m^2 N \mu_0}{3kT} \]

Final Answer: \( \chi = \frac{m^2 N \mu_0}{3kT} \).