set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

Photochemical smog occurs in warm, dry and sunny climate. One of the following is not amongst the components of photochemical smog, identify it.

a) O₃

b) SO₂

c) NO₂

d) Unsaturated hydrocarbon

Question : 2

Which one of the following is associated with the formation of brown air in traffic congested cities?

a) Carbon dioxide

b) Nitrogen oxide

c) Sulphur dioxide

d) Carbon monoxide

Question : 3

Which one of the following statement is not true?

a) Concentration of DO below 6 ppm is good for the growth of fish.

b) Clean water would have a BOD value of less than 5 ppm.

c) pH of drinking water should be between 5.5 – 9.5.

d) Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant.

Question : 4

Ozone layer in upper atmosphere (stratosphere) is destroyed by –

a) chlorofluoro carbon (CFC)

b) photochemical smog

c) hydrochloric acid

d) sulphur dioxide

Question : 5

The filament of an electric bulb is of tungsten because –

a) It is cheaper

b) Its resistance is negligible

c) Its melting point is high

d) Filament is easily made

Question : 6

Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because __________.

a) the reaction can be initiated only in presence of a catalyst.

b) oxides of nitrogen are unstable.

c) the reaction is endothermic and requires very high temperature.

d) N₂ and O₂ are unreactive.