set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

The polymeric fibre used as a substitute for wool in making synthetic blankets, sweaters, etc., is

a) orlon

b) teflon

c) nylon

d) Bakelite

Question : 2

Which of the following substances is/are ozone depleting?

1. Chlorofluorocarbons
2. Halons
3. Carbon tetrachloride

a) 1 and 2

b) 1 only

c) 2 and 3

d) 1, 2 and 3

Question : 3

Which of the following is the major cause of global warming?

a) re-radiation of I.R. rays by O₂ and N₂

b) re-radiation of I.R. rays by CO₂ and H₂O

c) re-radiation of U.V. rays by CO₂ and H₂O

d) re-radiation of U.V. rays by O₂ and N₂

Question : 4

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 : 5

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 : 6

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