Assertion: Electromagnets are made of soft iron.
Reason: Coercivity of soft iron is small.

There are $2.0 \times 10^{24}$ molecular dipoles in a paramagnetic salt. Each has a dipole moment of $1.5 \times 10^{-23} \text{ A m}^2$. Find the maximum (saturation) magnetization in the specimen. (in $\text{ A m}^2$)

$A$ sample of paramagnetic salt contains $2.0 \times 10^{24}$ atomic dipoles each of dipole moment $1.5 \times 10^{-23} \; J \, T^{-1}$. The sample is placed under a homogeneous magnetic field of $0.64 \; T$ and cooled to a temperature of $4.2 \; K$. The degree of magnetic saturation achieved is $15 \%$. What is the total dipole moment of the sample for a magnetic field of $0.98 \; T$ and a temperature of $2.8 \; K$? (Assume Curie's law)

Which of the following statements is true?

Assertion: $A$ paramagnetic sample displays greater magnetisation (for the same magnetic field) when cooled.
Reason: The magnetisation does not depend on temperature.

If the magnetic dipole moment of an atom of diamagnetic material,paramagnetic material,and ferromagnetic material are denoted by $\mu_d, \mu_p, \mu_f$ respectively,then: