set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

Sewage containing organic waste should not be disposed in water bodies because it causes major water pollution. Fishes in such a polluted water die because of

a) increase in the amount of dissolved oxygen

b) decrease in the amount of dissolved oxygen in water

c) large number of mosquitoes

d) clogging of gills by mud

Question : 2

Some statements about the benefits of organic farming are given below. Indicate whether they are true or false using the codes given below the statements :

1. It reduces CO₂ emissions.
2. It does not lead to toxic effects.
3. It improves the water-retention capacity of the soil.

a) False - True - True

b) True - False - False

c) False - True - False

d) False - True - True

Question : 3

Which among the following statements is false?

a) The main reason for river water pollution is industrial and domestic sewage discharge.

b) Surface water contains a lot of organic matter mineral nutrients and radioactive materials.

c) Oil slick in sea water increases D.O. value.

d) Oil spill in sea water causes heavy damage to fishery.

Question : 4

Which one of the following is not contained in Portland cement ?

a) Ca₂SiO₄

b) Ca₃SiO₅

c) Ca₃Al₂O₆

d) Ca₃(PO₄)₂

Question : 5

The false statement among the followings :

a) Limestone acts as a sink for $SO_x$

b) $SO_x$ can be removed from flue gases by passing through a solution of citrate ions

c) The average residence time of NO is one month

d) Ammonia acts as a sink for $NO_x$

Question : 6

It is said, the Tajmahal may be destroyed due to –

a) Air pollutants released from oil refinery of Mathura

b) Decomposition of marble as a result of high temperature

c) Flood in Yamuna river

d) All the above