Nuisance growth of aquatic plants and bloom-forming algae in natural waters is generally due to high concentrations of:

1. Carbon 2. Sulphur
3. Calcium 4. Phosphorus

Subtopic:  Water Pollution |
 76%
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Algal blooms impart a distinct colour to water due to:

1.  Their pigments
2.  Excretion of coloured substances
3.  Formation of coloured chemicals in water facilitated by physiological degradation of algae
4.  Absorption of light by algal cell wall

Subtopic:  Water Pollution |
 53%
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Match the items in column I and column II and choose the correct option:

Column I Column II
A. UV i. Biomagnifications
B. Biodegradable organic matter ii. Eutrophication
C. DDT iii. Snow blindness
D. Phosphates iv. BOD

Options: A B C D
1. ii i iv iii
2. iii ii iv i
3. iii iv i ii
4. iii i iv ii

Subtopic:  Ozone Layer Depletion | Water Pollution |
 91%
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In the textbook you came across “Three Mile Island and Chernobyl disasters associated with accidental leakage of radioactive wastes.” In India, we had Bhopal gas tragedy. It is associated with which of the following?

1.  CO2 2.  Methyl Isocyanate
3.  CFC 4.  Methyl Cyanate

Subtopic:  Agrochemical & Radioactive Waste |
 91%
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
 
Assertion (A): Photochemical smog is a primary air pollutant.
Reason (R): It is formed in traffic-congested cities where the conditions are cold and the intensity of solar radiation is less.

 In the light of the above statements, choose the most appropriate answer from the options given below:

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Air Pollution |

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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A):  According to CPCB, particulate size 2.5 micrometer or less in diameter [PM 2.5] are responsible for causing the greatest harm to human health.
Reason (R):  These fine particles can be inhaled deep into the lungs and can damage lungs.
 In the light of the above statements, choose the most appropriate answer from the options given below:
1.  Both (A) and (R) are true and (R) is the correct explanation of (A).
2.  Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.  (A) is true but (R) is false.
4.  Both (A) and (R) are false.
  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Air Pollution |
 90%

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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Motor vehicles equipped with catalytic converters should use unleaded petrol.
Reason (R): Lead poisoning affects brain and is responsible for many cases of intellectual disabilities.
In the light of the above statements, choose the most appropriate answer from the options given below:
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Air Pollution |
 57%

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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A):   Compressed natural gas poses less of a threat in the event of a spill.
Reason (R):  It is heavier than air and sediments to the surface quickly.
 In the light of the above statements, choose the most appropriate answer from the options given below :
1.  Both (A) and (R) are true and (R) is the correct explanation of (A).
2.  Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.  (A) is true but (R) is false.
4.  Both (A) and (R) are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Air Pollution |

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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): The presence of Tubifex in a water sample is a good indicator of high quality [non-polluted] of the water sample.
Reason (R): Tubifex is a nematode that cannot survive in water with low dissolved oxygen content.
In the light of the above statements, choose the most appropriate answer from the options given below:
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Water Pollution |

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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A):  Cultural eutrophication leads to decreased biodiversity in an aquatic ecosystem.
Reason (R): The primary limiting factor for eutrophication is phosphate.
 In the light of the above statements, choose the most appropriate answer from the options given below :
1.  Both (A) and (R) are true and (R) is the correct explanation of (A).
2.  Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.  (A) is true but (R) is false.
4.  Both (A) and (R) are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Water Pollution |
 57%

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