Which instrument is used for the determination of particle size?

Ferric chloride is applied to stop bleeding because :-

According to Graham,colloids are those substances which are

When the movement of dispersed particles is restricted,the movement of the dispersion medium under the influence of an electric field is called:

Smoke is a colloidal dispersion of :-

How are colloids classified on the basis of
$(i)$ physical states of components
$(ii)$ nature of dispersed phase and
$(iii)$ interaction between dispersed phase and dispersion medium?