Explain qualitatively on the basis of domain picture the lireversibility in the magnetisation curve of a ferromagnet.

Explain three phases of sigmoid curve.

Would the maximum possible magnetisation of a paramagnetic substance be of the same order of magnitude as the magnetisation of a ferromagnet ?

(a) Why photoelectric effect can not be explained on the basis of wave nature of light ? Give reasons. (b) Write the basic features of photon picture of electromagnetic radiation on which Einstein's photoelectric equation is based.

Explain the structure of CH_(4) on the basis of VSEPR theory.

Define intensity of radiation on the basis of photon picture of light. Write its S.I. unit.

Explain the regio of delta formation on the basis of co-agulation.

On the basis of electron gas theory explain the metallic lusture property.

A Rowland ring of mean radius 15 cm has 3500 tums of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2 A?

Explain sigmoid growth curve.

On the basis of Ellingham's diagram explain the principle of extraction of iron from its oxide ore.