Question

"Grey Air" refers to

• A. Incomplete smog formation
• B. $N_{2}O$
• C. CO
• D. $S{O}_2$

Answer 1

The correct option is A Incomplete smog formation

Photochemical smog is composed mainly of ozone (O${}_3$), Peroxyacetyl nitrate (PAN) and NOx. It is often called brown air where solar radiation is intense. In areas or seasons of lesser solar radiation smog formation is incomplete and the air is referred to as grey air.

So the correct answer is 'Incomplete smog formation'.