Which of the following colloidal solutions cannot be prepared by Bredig's arc method?

Give information about Emulsion.

The most suitable electrolyte for the coagulation of arsenic sulphide sol will be

The charges on the colloidal $CdS$ sol and $TiO_2$ sol are,respectively :

Colloidal solutions can be purified by

$Statement-1$: Micelles are formed by surfactant molecules above the critical micellar concentration $(CMC)$.
$Statement-2$: The conductivity of a solution having surfactant molecules decreases sharply at the $CMC$.