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Environment & EcologyMediumAsked in: RRB Group D · 12 Nov 2018, Shift 3

What should be the temperature difference between the upper layers and deeper layers of the ocean for setting up the OTEC power plant?

  1. A.40°C
  2. B.250°C
  3. C.50°C
  4. D.20°C

Correct answer

D. 20°C

Explanation

The correct answer is D, 20°C. An ocean thermal energy conversion plant works only where the warm surface water is at least about 20 degrees Celsius hotter than the cold water drawn from the depths.

OTEC uses that difference as its heat source. The warm surface water boils a liquid with a low boiling point, such as ammonia, and the vapour turns a turbine to make electricity; cold water pumped up from roughly a kilometre down condenses the vapour back to liquid so the cycle repeats. The gap of 20 degrees is needed because a smaller one leaves too little energy to run the pumps and still send power out. Such conditions are found in tropical seas, and India has tested OTEC near the Lakshadweep and Andaman islands.

Option A is wrong because a 40 degree gap does not occur between the surface and the deep sea. Option B is wrong because 250 degrees belongs to a furnace, not the ocean. Option C is wrong because 50 degrees is far beyond any natural ocean difference.

Exam tip: OTEC needs a surface to deep water difference of about 20°C and works best in tropical waters.

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.