set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

BOD is connected with

a) organic matter

b) microbes and organic matter

c) microbes

d) None

Question : 2

CO₂ absorbs some of the ............. that radiates from the surface of Earth to space –

a) ultraviolet light

b) heat

c) ozone

d) smog

Question : 3

The layer which reflects radio signals back to earth is –

a) Ionosphere

b) Troposphere

c) Ozone layer

d) Stratosphere

Question : 4

Which of the following is not involved in the formation of photochemical smog?

a) NO

b) SO₂

c) Hydrocarbon

d) O₃

Question : 5

The pollutants which came directly in the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?

a) Hydrocarbon

b) Peroxyacetyl nitrate

c) CO

d) NO

Question : 6

When rain is accompanied by a thunderstorm, the collected rain water will have a pH value

a) slightly higher than that when the thunderstorm is not there

b) uninfluenced by occurrence of thunderstorm

c) slightly lower than that of rain water without thunderstorm

d) which depends upon the amount of dust in air