Assertion: The ferromagnetic substance does not obey Curie's law.
Reason: At Curie point,a ferromagnetic substance starts behaving as a paramagnetic substance.

Diamagnetic substances are

$A$ perfectly diamagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field $\overrightarrow{B}$. Then the field inside the paramagnetic substance is:

The resultant force acting on a diamagnetic material in a non-uniform magnetic field is in the direction . . . . . . .

$A$ sample of a paramagnetic salt containing $3 \times 10^{24}$ atomic dipoles each of dipole moment $2 \times 10^{-23} \text{ A-m}^2$ is subjected to a uniform magnetic field of $880 \text{ mT}$ and cooled to a temperature of $3.5 \text{ K}$. The degree of magnetic saturation achieved is $10 \%$. If the sample is subjected to a magnetic field of $990 \text{ mT}$ and cooled to a temperature of $2.1 \text{ K}$, then the total dipole moment of the sample is (in $\text{ A-m}^2$)

Why is steel suitable for making permanent magnets?