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Environment & EcologyEasyAsked in: CTET · CTET Jan 2021 Paper 2 (Social Studies) (

Biogas is essentially a mixture of

  1. A.methane and hydrogen
  2. B.methane and helium
  3. C.methane and carbon dioxide
  4. D.methane and nitrogen

Correct answer

C. methane and carbon dioxide

Explanation

The correct answer is C, methane and carbon dioxide. Biogas is produced when cattle dung, crop waste and sewage are broken down by bacteria in a closed tank without air, a process called anaerobic digestion. The gas that collects is about 55 to 70 per cent methane and most of the rest is carbon dioxide, with small traces of hydrogen sulphide and water vapour. Methane is the part that burns, which is why biogas gives a clean blue flame and is used for cooking and lighting in villages; the slurry left behind is a good manure. A gobar gas plant thus turns waste into fuel and fertiliser at the same time. A is wrong because hydrogen is not a major part of biogas. B is wrong because helium is an inert gas that no bacteria produce. D is wrong because nitrogen is present only in traces and does not burn. Exam tip: biogas is mainly methane with carbon dioxide, made by anaerobic digestion, and its slurry is used as manure.

Practice Questions

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Q2.Environment & EcologyAsked in: CDS · CDS-I 2019, GKMedium

Which one of the following statements about the National Green Tribunal is not correct?

  1. A.It was set up in the year 2010.
  2. B.It is involved in effective and expeditious disposal of cases relating to environmental protection and conservation of forests.
  3. C.It may consider giving relief and compensation for damages to persons and property.
  4. D.It is bound by the procedures laid down under the Code of Civil Procedure, 1908.
Show answer
Correct answer: D. It is bound by the procedures laid down under the Code of Civil Procedure, 1908.

The National Green Tribunal is not bound by the Code of Civil Procedure; it is guided by the principles of natural justice.

Q3.Environment & EcologyAsked in: CDS · CDS-I 2018, GKHard

Consider the following statements about National Wildlife Action Plan (NWAP) of India for 2017-2031:

1. This is the Third National Wildlife Action Plan.

2. The NWAP is unique as this is the first time India has recognized the concerns relating to climate change impact on wildlife.

3. The NWAP has ten components.

Which of the statements given above is/are correct?

  1. A.1 only
  2. B.1 and 2 only
  3. C.2 and 3 only
  4. D.1, 2 and 3
Show answer
Correct answer: B. 1 and 2 only

The plan for 2017-2031 is India's third National Wildlife Action Plan and the first to deal with the impact of climate change on wildlife, but it has five components, not ten.