Fill in the blank :
$(i)$ The domain size is ...... .
$(ii)$ The domain contains about ...... atoms.

Explain hard ferromagnetic and soft ferromagnetic materials.

Magnetic shielding is done by surrounding the instrument to be protected from magnetic field by

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

Given below are two statements; one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Electromagnets are made of soft iron.
Reason $R:$ Soft iron has high permeability and low retentivity.
In the light of the above statements,choose the most appropriate answer from the options given below.

Assertion : Diamagnetic materials can exhibit magnetism.
Reason : Diamagnetic materials have permanent magnetic dipole moment.