RRB RPF RPSF SI and CONS Model Papers 4 with solutions

(2) Zinc oxide (ZnO) is called as the philosopher's wool. Alchemists as a part of their ritual, would burn zinc in air and collect the residue which formed into white woolly turfts. Zinc Oxide has many uses such as in white pigment in paints, in treatment of various skin diseases, photocopying etc.