TS EAMCET 11-Sep-2020 Shift 1 Solved Paper

Photochemical smog is a type of smog produced, when ultraviolet light from the sun reacts with nitrogen oxides in the atomosphere. It is visible as a brown haze and is most prominent during the morning and afternoon, especially in densey populated, warm cities.
Photochemical smog = mixture of ozone, nitric acid, aldehydes, peroxyacyl nitrates and secondary pollutants.