Which one of the following is not responsible for the depletion of ozone layer:
Correct Answer:
(B)
Methyl chloroform used as a solvent
The ozone layer in the atmosphere prevents harmful ultraviolet rays from reaching the Earth's surface. It thus safeguards life on Earth. Gases responsible for the depletion of the ozone layer are– CFC, Halon - 1211, 1301, Nitrous oxide and Trichloroethylene etc.
Ques:
42
Among the following greenhouse gases, which does not cause ozone depletion in the troposphere?
Correct Answer:
(B)
Carbon monoxide
The greenhouses gases responsible for ozone depletion in the troposphere are- Water vapour, Carbon dioxide, Methane, Ozone, Nitrous oxide and Chlorofluorocarbons.
Ques:
43
Formation of the ozone hole is maximum over –
Correct Answer:
(C)
Antarctica
The ozone hole is not technically a “hole” where no ozone is present but is a region of exceptionally depleted ozone in the stratosphere over Antarctica.
Ques:
44
Consider the following statements: Chlorofluorocarbons, known as ozone-depleting substances, are used
In the production of plastic foams.
In the production of tubeless tires.
In cleaning certain electronic components.
As pressurizing agents in aerosol cans.
Which of the statements given above is/are correct?
Correct Answer:
(C)
1, 3 and 4
Chlorofluorocarbons (CFCs) are nontoxic, non-flammable chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants. Trichlorofluoromethane can dissolve grease and used to clean electronic equipment. It is a highly stable compound and can sustain in the atmosphere for 80 to 100 years. Hence option (C) is the correct answer.
Ques:
45
Which of the following substances is/are ozone depleting?
Select the correct answer from codes given below:
Chlorofluorocarbons
Halans
Carbon tetrachloride
Codes :
Correct Answer:
(D)
1, 2 and 3
Chlorofluorocarbons, Halans and Carbon tetrachloride, all are ozone-depleting substances. All these substances are banned after the Montreal Protocol.
Ques:
46
The formation of the ozone hole in the Antarctic region has been a cause of concern. What could be the reason for the formation of this hole?
Correct Answer:
(B)
Presence of prominent polar front and stratospheric clouds and inflow of chlorofluorocarbons
Nitric Acid in the Polar stratospheric clouds react with chlorofluorocarbon. This reaction produces chlorine which is responsible for photo-chemical destruction of the ozone layer. Since stratospheric clouds help chlorine compound to convert in chlorine particles depleting the ozone layer, their presence is also a factor responsible for the formation of the ozone hole.
Ques:
47
Which gas is filled in refrigerators?
Correct Answer:
(B)
Mafron
The gases filled in the refrigerator are sold as Mafron. These gases are a commonly halonic hydrocarbon. Although, Ammonia is also used as a coolant in big plants, the correct answer to this question is option (b).
Ques:
48
Polythene bags cannot be destroyed because they are made of –
Correct Answer:
(C)
Polymers
Polythene is made up of molecules of carbon and hydrogen. It is a polymer of ethylene (C2H4). It is non-biodegradable. This is the reason why polythene bags cannot be destroyed.
Ques:
49
Which of the following is not destroyed by bacteria?
Correct Answer:
(D)
Plastic
Plastic, Iron, lead are non-biodegradable pollutants which are not destroyed by bacteria. Hence, they pollute the atmosphere. Rest of all are easily disintegrated by the micro-organism.
Ques:
50
Consider the following statements:
1. India generates approximately 9.3 million tonnes of plastic pollution annually.
2. India’s waste generation rate is approximately 0.12 kilograms per capita per day.
Which of the statements given above is/are correct?
Correct Answer:
(C)
Both 1 and 2
Plastic Waste Generation:
India generates approximately 9.3 million tonnes of plastic pollution annually. Out of this, 5.8 million tonnes (mt) are incinerated, while 3.5 million tonnes are released into the environment as debris.
This figure is significantly higher than Nigeria (3.5 mt), Indonesia (3.4 mt), and China (2.8 mt).
India’s waste generation rate is approximately 0.12 kilograms per capita per day.