Q52 · UPPSC Prelims 2023 · Set A · General Studies

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The 'Ozone layer' absorbing ultraviolet radiation exists in which atmospheric layer?

A Troposphere
B Mesosphere
C Stratosphere
D Thermosphere

Correct answer: (c) Stratosphere

Explanation

  1. A

    Troposphere

    Option (a) claims the ozone layer is located in the troposphere. This is incorrect because the troposphere is the lowest layer of the atmosphere where weather phenomena occur, whereas ozone is primarily found much higher up.

  2. B

    Mesosphere

    Option (b) states that the ozone layer resides in the mesosphere. This is incorrect since the mesosphere lies above the stratosphere and is characterized by extremely cold temperatures rather than high ozone concentrations.

  3. C

    Stratosphere

    Option (c) maintains that the ozone layer absorbing harmful ultraviolet radiation exists in the stratosphere. This is the correct official key because the stratosphere contains the highest concentration of ozone molecules, forming the critical ozone layer that protects life on Earth by absorbing most of the sun's ultraviolet radiation.

  4. D

    Thermosphere

    Option (d) suggests that the ozone layer is situated in the thermosphere. This is incorrect because the thermosphere is located in the upper atmosphere well above the mesosphere, where high-energy X-rays and UV radiation from the sun are absorbed by gases like oxygen and nitrogen, not by an ozone layer.

Summary. Official key is (c) Stratosphere. The question asks for the specific atmospheric layer that contains the ozone layer responsible for absorbing harmful ultraviolet radiation. While the troposphere handles weather and the upper layers experience different thermal characteristics, the stratosphere holds the peak concentration of atmospheric ozone. Candidates often confuse the troposphere with the stratosphere due to general atmospheric stratification. Therefore, option (c) is the only correct and comprehensive choice.

Same topic · past papers

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These previous-year questions sit on the same topic. Open one to practise the earlier ask.

  1. 2025 · Q45 · UPPGS

    With reference to 'ozone layer', which of the following statements is/are correct? 1. Ozone layer shields the surface of the earth from the ultra-violet radiations from the sun. 2. Ozone depletion has been linked to the chlorofluorocarbons. Select the correct answer from the code given below:

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