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Environment & EcologyMediumAsked in: CDS · CDS-II 2020, GK

Which one of the following statements with regard to ozone is not correct?

  1. A.Ozone is found mostly at 15-55 km in the atmosphere.
  2. B.Ozone is produced by gaseous chemical reactions.
  3. C.16th November is celebrated as the International Day for the Preservation of the Ozone Layer.
  4. D.Ozone is a form of oxygen in which three oxygen atoms are bounded together.

Correct answer

C. 16th November is celebrated as the International Day for the Preservation of the Ozone Layer.

Explanation

The correct answer is C. The International Day for the Preservation of the Ozone Layer is observed on 16 September, not 16 November.

The date marks the signing of the Montreal Protocol on 16 September 1987, the treaty that phased out chlorofluorocarbons and other ozone-depleting substances. The UN General Assembly declared the day in 1994, and it was first observed in 1995. Ozone, O3, is a molecule of three oxygen atoms. Most of it lies in the stratosphere, where ultraviolet rays split oxygen molecules into single atoms that then join other oxygen molecules to form ozone. This layer absorbs most of the Sun's harmful ultraviolet-B radiation.

Option A is correct as a statement, because most ozone is found in the stratosphere, roughly between 15 and 55 km. Option B is correct, because ozone forms through chemical reactions of gases driven by sunlight. Option D is correct, because ozone is an allotrope of oxygen made of three atoms bonded together.

Exam tip: Ozone Day 16 September (Montreal Protocol, 1987); Earth Day 22 April; Environment Day 5 June.

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Q2.Environment & EcologyAsked in: CDS · CDS-II 2023, GKEasy

Energy and nutrients flow from one trophic level to another in an ecosystem. Which one of the following statements correctly describes the direction of flow of energy and nutrients in an ecosystem ?

  1. A.Energy flow is cyclic and nutrient flow is unidirectional.
  2. B.Energy flow is unidirectional and nutrient flow is cyclic.
  3. C.Both energy and nutrient flow are unidirectional.
  4. D.Both energy and nutrient flow are cyclic.
Show answer
Correct answer: B. Energy flow is unidirectional and nutrient flow is cyclic.

Energy passes one way from the Sun through the food chain and is lost as heat, while nutrients are used again and again.

Q3.Environment & EcologyAsked in: CDS · CDS-II 2026, GKEasy

UNESCO World Heritage site Nanda Devi National Park is located in which one of the following States ?

  1. A.Arunachal Pradesh
  2. B.Uttarakhand
  3. C.Himachal Pradesh
  4. D.Sikkim
Show answer
Correct answer: B. Uttarakhand

Nanda Devi National Park lies in the Chamoli district of Uttarakhand, around India's second-highest peak, Nanda Devi. The park is a vast glacial basin ringed by high peaks and was inscribed on the UNESCO World Heritage list in 1988 for its wild, untouched landscape.

Q4.Environment & EcologyAsked in: CDS · CDS-I 2024, GKMedium

Which one of the following is related to global dimming?

  1. A.Fall of atmospheric pressure due to increased particulates
  2. B.Rise of atmospheric pressure due to increased particulates
  3. C.Rise of temperature due to increased particulates
  4. D.Fall of temperature due to increased particulates
Show answer
Correct answer: D. Fall of temperature due to increased particulates

Global dimming is the drop in sunlight reaching the ground, and the cooling that follows, caused by particles in the air.