Answer:
1. Answer : (b) Paddy field
Explanation: Rice crops are grown on paddy fields. Hence, the agricultural field that produces the maximum methane gas into the atmosphere is paddy field.
2. Answer : (b) Fluorides in water
Explanation: Skeletal fluorosis is a bone disease caused by excessive accumulation of fluoride in the bones. In advanced cases, skeletal fluorosis causes painful damage to bones and joints.
3. Answer : (d) CO
Explanation: CO is odorless, colorless, and poisonous gas is formed by the combustion of fossil fuels such as gasoline and is emitted primarily from cars and trucks.
4. Answer : (d) Freons
Explanation: Freons or chlorofluoro carbons (CFC) are responsible for depletion of ozone layer in the upper strata of the atmosphere.They are used as propellants, aerosol spray caps, refrigerants, fire fighting reagents etc.
5. Answer : (c) Microorganisms present in the soil
Explanation: CO is converted into CO2 by micro- organism present in soil.
6. Answer : (b) Biodegradable pollution
Explanation: Domestic waste mostly constitutes biodegradable pollution.
7. Answer : (d) Nuclear Fallout
Explanation: Nuclear fallout, or simply fallout, is the residual radioactive material propelled into the upper atmosphere following a nuclear blast or a nuclear reaction conducted in an unshielded facility.
8. Answer : (a) Minamata disease
Explanation: Mercury is changed to water soluble dimethyl mercury which undergoes biomagnification. Eating poisoned animals causes deformity known as Minamata disease (first reported in 1952 due to eating of fish captured from Hg-contaminated Minimata Bay of Japan) which is characterised by diarrhoea, hemolysis, impairment of various senses, numbness of lips, tounge, limbs, deafness, blurring of vision, mental dearrangement, meningitis and death.
9. Answer : (b) reduce the use and production of hazardous chemicals
Explanation: Green chemistry means such reactions which reduce the use and production of hazardous chemicals. Green chemistry is the use of chemistry for pollution prevention by an environmentally conscious design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances.
10. Answer : (b) Motor vehicles
Explanation: Motor vehicles are the greatest air pollutants these days as day by day with increase in population, the number of motor vehicles also increased and motor vehicles causes high emission of CO2 gas, thereby causing pollution.
11. Answer : (a) N2O5
Explanation: Dinitrogen pentoxide is an unstable and dangerous oxidiser, which contains only nitrogen and oxygen. It is formed when oxygen and nitrogen react. In the atmosphere it attracts NOX gases that cause depletion of the ozone layer.
12. Answer : (a) sulphur dioxide
Explanation: The primary greenhouse gases present around us are carbon dioxide, methane, nitrous oxide, ozone and water vapours etc. Thus, the gas which is not green house gas from the options given to us is Sulphur dioxide.
13. Answer : (d) Using plastic cans for neatly storing substances
Explanation: Plastics are non-biodegradable, hence are not environmental friendly.
14. Answer : (b) Biosphere
Explanation: The biosphere is the region of the earth that encompasses all living organisms: plants, animals and bacteria.
15. Answer : (c) USA
Explanation: Depletion in the concentration of ozone over a restricted area as spring time decline over Antartica is called ozone hole. Depletion of ozone is due to action of sunlight over pollutants which release chemicals (e.g., chlorine) that destroy ozone. Major contributor of these gases is USA.
16. Answer : (c) Human waste
Explanation: The Ganges river basin is one of the most fertile and densely populated regions in the world that covers an area of 1,80,000 km2. The river flows through 29 cities with population over 100,000; 23 cities with population between 50,000 and 100,000, and about 48 towns. A large proportion of the waste in the Ganges is from this population through domestic usage like bathing, laundry and public defecation. An analysis of the Ganges water in 2006 showed significant associations between waterborne or enteric disease due to the use of the river for bathing, laundry, washing, eating, cleaning utensils, and brushing teeth.
17. Answer : (d) H2SO4
Explanation: Sulphuric acid(H2SO4) is present in a larger concentration in acid rain. Acid rain is formed due to the presence of oxides of sulphur and nitrogen in the atmosphere.
18. Answer : (c) SO2
Explanation: The smog which is formed in presence of sunlight is called photochemical smog. This occurs in the months of summer when NO2 and hydrocarbons are present in large amounts in atmosphere.SO2 is not responsible for photochemical smog because concentration of O3. PAN, aldehyde and ketones builds up in the atmosphere.
19. Answer : (d) Air, water and soil
Explanation: Spraying of DDT chemicals leads to the pollution of the air, soil and water. DDT and other agrochemicals are release greenhouse gasses to the environment which causes ozone depletion.
20. Answer : (c) Peroxyacetyl nitrate
Explanation: Peroxyacetyl nitrate (PAN), formed from the primary pollutants NO2, O3 and hydrocarbons, is the secondary pollutant.
21. Answer : (b) Troposphere
Explanation: Troposphere is the lowest region and extends upto 10 km from the sea level. This layer envelops 80% of the total mass of the air and spreads widely.
22. Answer : (a) rich in dissolved oxygen
Explanation: Clean water has BOD which is less than 5 ppm. If it is equal to or more than 12 ppm, then the water is considered as polluted. So this indicates water be rich in dissolved oxygen, that helps the microorganisms to oxidize inorganic and organic materials.
23. Answer : (c) Decrease in the amount of dissolved oxygen in water
Explanation: Low dissolved oxygen(DO) is usually the major contributor to fish kills, make some fish species more vulnerable to environmental stress.Fishkill can occur with rapid fluctuations in temperature or sustained high can lead decreased dissolved oxygen(DO) in a body of water.
24. Answer : (b) Coal
Explanation: Coal is classified as a nonrenewable energy source because it takes millions of years to form. Coal contains the energy stored by plants that lived hundreds of millions of years ago in swampy forests.
25. Answer : (a) Noosphere
Explanation: When biosphere turns into human dominated environment it is called noosphere. The noosphere is the sphere of human thought. The noosphere emerges through and is constituted by the interaction of human minds. The noosphere has grown in step with the organization of the human mass in relation to itself as it populates the Earth.As mankind organizes itself in more complex social networks, the higher the noosphere will grow in awareness.
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