Pollution

51. Arrange the following fuels in the decreasing order of air pollution c

Arrange the following fuels in the decreasing order of air pollution caused by burning a kilogram of each of them :

[amp_mcq option1=”CNG, Petrol, Diesel” option2=”Diesel, Petrol, CNG” option3=”Petrol, Diesel, CNG” option4=”Diesel, CNG, Petrol” correct=”option2″]

This question was previously asked in
UPSC CAPF – 2014
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The question asks to arrange fuels in decreasing order of air pollution caused by burning a kilogram of each. Generally, different fuels produce varying amounts of pollutants like particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons, and sulfur oxides (SOx).
– Diesel: Diesel fuel is heavier than petrol and its combustion typically produces more particulate matter and higher levels of NOx, especially from older engines or those without modern emission controls. It can also contain more sulfur, leading to SOx emissions.
– Petrol (Gasoline): Petrol combustion produces significant amounts of CO, NOx, and unburnt hydrocarbons. While generally producing less PM than diesel, its emissions of other pollutants can be substantial.
– CNG (Compressed Natural Gas): CNG is primarily methane (CH4). Burning CNG is considered much cleaner than burning petrol or diesel. It produces significantly lower levels of PM, CO, NOx, and hydrocarbons. It contains virtually no sulfur, so no SOx emissions.
Ranking from most polluting to least polluting per kilogram burned (considering typical emissions profiles): Diesel > Petrol > CNG.
Therefore, the decreasing order of air pollution caused is Diesel, Petrol, CNG.
Understand the relative environmental impact and pollution characteristics of common fuels like Diesel, Petrol, and CNG. CNG is generally considered the cleanest of the three in terms of air pollutant emissions.
The specific emissions profile can vary depending on engine technology, fuel quality, and emission control systems (like catalytic converters). However, the general ranking of CNG being cleaner than petrol, which is cleaner than diesel (especially regarding PM) is widely accepted in the context of conventional engines.

52. Pesticide treadmill refers to :

Pesticide treadmill refers to :

[amp_mcq option1=”Increase in concentration of pesticides in the body of the organism” option2=”Increase in doses of pesticides to prevent the resurgence of pests that were being controlled” option3=”Development of resistance in plant due to excessive and prolonged use of pesticide” option4=”Production of more synthetic pesticides” correct=”option2″]

This question was previously asked in
UPSC CAPF – 2014
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Pesticide treadmill refers to the cycle where increasing amounts or more potent pesticides are needed because target pest populations develop resistance to the chemicals being used.
Pesticide resistance occurs through natural selection. When a pesticide is applied, it kills susceptible individuals, but some individuals with resistance genes survive. These survivors reproduce, passing on their resistance. Over time, the population becomes dominated by resistant individuals. This renders the original pesticide ineffective at its previous dose, requiring higher doses or the use of different, often stronger, pesticides to achieve control. This escalating use of pesticides is the “treadmill”.
This phenomenon has significant environmental and economic consequences, including increased costs for pest control, potential harm to non-target organisms, pollution of soil and water, and health risks associated with higher pesticide exposure. Integrated Pest Management (IPM) strategies aim to break this cycle by using a combination of methods (biological, cultural, physical, and chemical) to manage pests sustainably.

53. Green Muffler is

Green Muffler is

[amp_mcq option1=”a technology for reducing air pollution” option2=”a method of afforestation” option3=”plantation along roadsides to reduce noise pollution” option4=”a process of reducing vibration” correct=”option3″]

This question was previously asked in
UPSC CAPF – 2012
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The correct answer is C) plantation along roadsides to reduce noise pollution.
The term “Green Muffler” refers to the concept of using trees and shrubs planted in strategic locations, often in multiple rows along roads, highways, and industrial areas, to absorb and dissipate sound waves, thereby reducing noise pollution. The dense foliage acts as a barrier and a sound-absorbing medium.
While trees contribute to reducing air pollution (A) and are part of afforestation efforts (B), the specific term “Green Muffler” is predominantly associated with noise reduction through vegetation. It does not relate to reducing vibration (D).

54. Which one of the following consequences will happen if large quantitie

Which one of the following consequences will happen if large quantities of domestic sewage are continuously discharged in a stream ?

[amp_mcq option1=”Increase in the algal bloom of the stream water” option2=”Increase in the temperature level of the stream water” option3=”Reduction in the carbon dioxide level of the stream water” option4=”Reduction in the dissolved oxygen level of the stream water” correct=”option4″]

This question was previously asked in
UPSC CAPF – 2011
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Discharging large quantities of domestic sewage into a stream will result in a reduction in the dissolved oxygen level of the stream water.
Domestic sewage contains a high concentration of organic matter. Decomposers (primarily aerobic bacteria) break down this organic matter, a process that consumes large amounts of dissolved oxygen from the water (high Biochemical Oxygen Demand – BOD).
A significant drop in dissolved oxygen can be detrimental or fatal to fish and other aquatic organisms, leading to their death and disruption of the aquatic ecosystem. While sewage also contains nutrients that can lead to algal blooms (eutrophication), the immediate and most critical consequence for aquatic life is the depletion of dissolved oxygen.

55. What is the correct sequence for treatment of polluted surface water ?

What is the correct sequence for treatment of polluted surface water ?

  • 1. Disinfection and fluoridation
  • 2. Screening and mixing
  • 3. Flocculation and sedimentation
  • 4. Filtration and sludge processing

Select the correct answer using the code given below :

[amp_mcq option1=”1-2-3-4″ option2=”3-4-1-2″ option3=”2-3-4-1″ option4=”3-2-1-4″ correct=”option3″]

This question was previously asked in
UPSC CAPF – 2011
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The correct sequence for the typical treatment of polluted surface water from the given options is 2-3-4-1. This corresponds to Screening & mixing, followed by Flocculation & sedimentation, then Filtration & sludge processing, and finally Disinfection & fluoridation.
The standard sequence of surface water treatment involves removing large debris (screening), coagulating small particles (mixing, flocculation), settling the flocs (sedimentation), removing remaining suspended particles (filtration), and killing microorganisms (disinfection). Optional steps like fluoridation are added after disinfection. Sludge processing is a parallel or subsequent treatment for the solid waste generated.
The complete conventional water treatment process typically includes: 1. Screening (removes large debris), 2. Aeration (optional, adds oxygen), 3. Coagulation (chemicals added to neutralize charges), 4. Flocculation (gentle mixing to form larger flocs), 5. Sedimentation/Clarification (settling of flocs), 6. Filtration (removes smaller particles), 7. Disinfection (kills pathogens, e.g., chlorination, UV, ozonation), 8. pH adjustment (if needed), 9. Fluoridation (optional, adds fluoride for dental health), 10. Sludge treatment (handling waste from sedimentation and filtration). The provided options represent key stages in this overall process in sequential order.

56. Which one of the following is a component of both the Basal Convention

Which one of the following is a component of both the Basal Convention and the Stockholm Convention?

[amp_mcq option1=”Mercury” option2=”Plastic waste” option3=”Persistent organic pollutants” option4=”Heavy metals” correct=”option3″]

This question was previously asked in
UPSC CAPF – 2010
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The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal regulates the movement and disposal of hazardous and other wastes. The Stockholm Convention on Persistent Organic Pollutants (POPs) aims to eliminate or restrict the production and use of POPs and reduce their release into the environment. Hazardous wastes covered under the Basel Convention can include wastes containing POPs. The Stockholm Convention also addresses the environmentally sound management and disposal of POPs, which when in waste form, fall under the purview of the Basel Convention for transboundary movement. Therefore, Persistent Organic Pollutants are a component relevant to both conventions, especially in the context of POPs waste.
While Basel deals broadly with hazardous waste and Stockholm deals with specific persistent organic pollutants, the intersection occurs when POPs become waste, making POPs a relevant element to both agreements.
The Basel Convention was adopted in 1989 and entered into force in 1992. The Stockholm Convention was adopted in 2001 and entered into force in 2004. Other options like Mercury are covered by the Minamata Convention, and Plastic waste was recently added to the scope of the Basel Convention but is not the primary focus of the Stockholm Convention.

57. Directions : Each of the next FIVE (05) items consists of two statemen

Directions : Each of the next FIVE (05) items consists of two statements, one labelled as the Assertion (A) and the other as ‘Reason (R)’. You are to examine these two statements carefully and select the answers to these items using the codes given below :
Codes :
Assertion (A) : Import of Chinese toys was recently banned by the Government of India.
Reason (R) : The plastic material used to make the toys are not biodegradable.

[amp_mcq option1=”Both A and R are individually true and R is the correct explanation of A” option2=”Both A and R are individually true but R is not the correct explanation of A” option3=”A is true but R is false” option4=”A is false but R is true” correct=”option2″]

This question was previously asked in
UPSC CAPF – 2009
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Assertion (A) is true, and Reason (R) is true, but R is not the correct explanation of A.
– Assertion (A) states that the import of Chinese toys was recently banned by the Government of India. This is a factual statement that aligns with events that occurred around 2009 when India imposed a temporary ban on certain toy imports from China.
– Reason (R) states that the plastic material used to make the toys is not biodegradable. This is generally true; many types of plastic commonly used in toys are not biodegradable.
– However, the primary reason cited by the Government of India for the ban on Chinese toys was not their non-biodegradability, but rather concerns about safety and quality standards, specifically high levels of lead and other toxic chemicals hazardous to children’s health.
– Therefore, while both statements are individually true, the non-biodegradability of the plastic was not the reason for the import ban. R is not the correct explanation for A.
– The temporary ban in 2009 was imposed following tests that found excessive levels of lead and other hazardous chemicals in samples of Chinese toys.
– This highlights how regulatory decisions, especially regarding imports, are often driven by concerns for public health, safety, and adherence to quality standards, rather than environmental factors like biodegradability, although environmental concerns are also important in other policy contexts.

58. Which one of the following is a major environmental issue in eastern

Which one of the following is a major environmental issue in eastern Canada?

[amp_mcq option1=”Acid precipitation” option2=”Groundwater depletion” option3=”Land degradation” option4=”Desertification” correct=”option1″]

This question was previously asked in
UPSC NDA-2 – 2020
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Acid precipitation (acid rain) has been a historically significant environmental issue in eastern Canada. Due to its geographical location downwind from major industrial areas in the Midwestern United States and central Canada, eastern Canada receives atmospheric pollutants, primarily sulfur dioxide and nitrogen oxides, which lead to the acidification of lakes, damage to forests, and degradation of infrastructure.
Eastern Canada is particularly vulnerable to transboundary air pollution leading to acid rain due to prevailing wind patterns and proximity to industrial regions.
While groundwater depletion and land degradation can be local or regional issues, and desertification is irrelevant to eastern Canada’s climate, acid precipitation was identified as a major widespread environmental problem in the region starting in the late 20th century, prompting significant domestic and international efforts to reduce emissions (e.g., Canada-US Acid Rain Accord).

59. Which one of the following is a cause of acid rains?

Which one of the following is a cause of acid rains?

[amp_mcq option1=”Ozone” option2=”Ammonia” option3=”Sulphur dioxide” option4=”Carbon monoxide” correct=”option3″]

This question was previously asked in
UPSC NDA-2 – 2017
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The correct answer is C.
Sulphur dioxide (SO₂) and nitrogen oxides (NOx) are the primary atmospheric pollutants that cause acid rain. They react with water, oxygen, and other chemicals to form sulfuric and nitric acids.
These pollutants are mainly emitted from the burning of fossil fuels by power plants, vehicles, and industrial facilities. Ozone, Ammonia, and Carbon monoxide are also atmospheric pollutants, but SO₂ and NOx are the principal precursors of acid rain.

60. Which one of the following sectors is the largest contributor to carbo

Which one of the following sectors is the largest contributor to carbon dioxide emissions from fuel consumption in India ?

[amp_mcq option1=”Electricity and heat production” option2=”Transport” option3=”Manufacturing industries and constructions” option4=”Others” correct=”option1″]

This question was previously asked in
UPSC NDA-2 – 2016
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The correct answer is Electricity and heat production.
In India, the combustion of fossil fuels, primarily coal, for electricity generation is the largest single source of carbon dioxide emissions.
India relies heavily on thermal power plants, mainly coal-based, to meet its energy demands. Burning coal for power generation releases significant amounts of CO2, making the electricity and heat production sector the largest contributor to India’s CO2 emissions from fuel combustion. While other sectors like transport and manufacturing also contribute substantially, the power sector’s emissions are significantly higher due to the large scale of fossil fuel (especially coal) consumption.
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