$A$ frog can be levitated in a magnetic field produced by a current in a vertical solenoid placed below the frog. This is possible because the body of the frog behaves as

$A$ sample of paramagnetic salt contains $2 \times 10^{24}$ atomic dipoles each of dipole moment $1.5 \times 10^{-23} \text{ J T}^{-1}$. The sample is placed under a homogeneous magnetic field of $0.6 \text{ T}$ and cooled to a temperature of $4.2 \text{ K}$. The degree of magnetic saturation achieved is $20 \%$. What is the total dipole moment of the sample for a magnetic field of $0.9 \text{ T}$ and a temperature of $2.8 \text{ K}$ (in $\text{ J T}^{-1}$)?

Substances in which the magnetic moment of a single atom is not zero are known as:

$A$ paramagnetic sample shows a net magnetization of $0.8 \text{ A m}^{-1}$ when placed in an external magnetic field of strength $0.8 \text{ T}$ at a temperature of $5 \text{ K}$. If the temperature is raised to $20 \text{ K}$, then the magnetization becomes: (in $\text{ A m}^{-1}$)

At a temperature of $30\,^{\circ}\text{C}$,the susceptibility of a ferromagnetic material is found to be $\chi$. Its susceptibility at $333\,^{\circ}\text{C}$ is......$\chi$.

The variation of the intensity of magnetisation $(I)$ with respect to the magnetising field $(H)$ in a diamagnetic substance is well described by the graph