a.
The positively charged colloidal particles of Fe(OH)3
get coagulated by the oppositely charged Clc-
ions provided by NaCl
. ltbr.b.
On passing direct current , colloidal particles move towards the oppositely charged electrodes where they lose their charge and get coagulated. ltbr. c
. Scattering of light by the colloidal particels takes place and the path of light becomes visible (
Tyndall effect )
.