Question

If ${{M}_{2}}$ = magnetization of a paramagnetic sample, B = external magnetic field, T = absolute temperature, C = curie constant then according to Curie's law in magnetism, the correct relation is
A- ${{M}_{2}}=\dfrac{T}{CB}$
B- ${{M}_{2}}=\dfrac{CB}{T}$
C- $C=\dfrac{{{M}_{2}}}{T}$
D- $C=\dfrac{{{T}^{2}}}{{{M}_{2}}B}$

Answer 1

The Curie law states that in a paramagnetic material the magnetization induced is directly proportional to the applied magnetic field. But when the material is heated it does not hold. When it is heated, the relation is reversed i.e. the magnetization becomes inversely proportional to the temperature.

Complete step by step answer:
According to Curie’s law, $\alpha =\dfrac{C}{T}$
The constant C in the numerator in RHS is called curie’s constant. $\aleph$is the magnetic susceptibility. T is the temperature of the material. Also, magnetization is given by the formula, M= $\aleph$B
Thus, ${{M}_{2}}=\dfrac{CB}{T}$.

So, the correct answer is “Option B”.

Additional Information:
On increasing the temperature magnetic susceptibility decreases. This holds for paramagnetic substances. On the other hand, ferromagnetic substances are those which hold permanent magnetization even during the absence of magnetic fields. The Curie Weiss law describes the magnetic susceptibility of a ferromagnet in the paramagnetic region above the Curie point. But there exists a class of substances for those even curie Weiss law fails to describe the susceptibility.

Note:
Curie temperature behaves like a red line or defining limit. The temperature above which a ferromagnetic substance becomes a paramagnetic is called a curie temperature. We can say in other words that the minimum temperature at which a ferromagnetic substance becomes paramagnetic. At this temperature ferromagnetism quashes.