Environmental Studies · Geography

Atmospheric Structure and Ozone

1,401 Questions

Atmospheric structure and ozone layer topics examine the Earth's atmospheric layers, the impact of solar radiation, and ozone depletion mechanisms. These environmental science concepts are crucial for general awareness sections in multiple competitive examinations. Review these questions to solidify your understanding of the stratosphere, polar vortex effects, and greenhouse gases.

Earth's atmospheric layersOzone layer depletionSolar ultraviolet radiationPolar vortex effectsCarbon dioxide impactOzone-depleting substances

Atmospheric Structure and Ozone Questions

Multiple choice

Which is the highest atmospheric layer that can be accessed by jet-powered aircrafts?

  1. Exosphere

  2. Stratosphere

  3. Thermosphere

  4. Mesosphere

  5. Troposphere
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The stratosphere is almost completely free of clouds and other forms of weather. However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. This is the highest layer that can be accessed by jet-powered aircraft.

Multiple choice

Directions: In the question below, the first and the last (correctly ordered) sentences are numbered 1 and 6, respectively. The rest of the passage is split into four parts and labelled B, C, D and E. These four parts are not given in a proper order. Choose the correct combination from the given alternatives.

  1. The atmosphere of Earth serves as a key factor in sustaining the planetary ecosystem. B. Dry air consists of 78% nitrogen, 21% oxygen, 1% argon and other inert gases, such as carbon dioxide. C. The remaining gases are often referred to as trace gases, among which are the greenhouse gases such as water vapour, carbon dioxide, methane, nitrous oxide and ozone. D. The thin layer of gases that envelops Earth is held in place by the planet's gravity and is called air. E. Filtered air includes trace amounts of many other chemical compounds.
  2. Air also contains a variable amount of water vapour and suspensions of water droplets and ice crystals seen as clouds.

  1. BCDE

  2. DBCE

  3. EBCD

  4. EDBC
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

D is linked with 1 with the word ‘ecosystem’ and introduction of air. B explains the statement given in D. ‘The remaining gases’ in C refers to ‘gases’ in B. ‘Filtered air includes’ in E and ‘Air also contains’ in 6 connect them.

Multiple choice

Which of the following group shows the different layers of atmosphere in the correct sequence?

  1. Troposphere, Ionosphere, Stratosphere Exosphere

  2. Stratosphere, Exosphere, Ionosphere, Troposphere

  3. Troposphere, Stratosphere, Ionosphere, Exosphere

  4. Ionosphere, Stratosphere, Exosphere, Troposphere
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The atmospheric layers from Earth's surface upward are: Troposphere (0-12km, where weather occurs), Stratosphere (12-50km, contains ozone layer), Ionosphere (part of upper atmosphere, 60km+ where ions are present), and Exosphere (outermost layer, fading into space). Option C presents this correct vertical sequence.

Multiple choice

The ozone layer in the upper part of the atmosphere protects us from

  1. Cosmic rays

  2. Ultrasonic waves

  3. Infra-red rays

  4. Ultraviolet rays
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ozone layer in the stratosphere absorbs most of the Sun's ultraviolet (UV) radiation, protecting living organisms from harmful UV rays that can cause skin damage. It does not primarily block cosmic rays, ultrasonic waves, or infrared rays.

Multiple choice

The ozone layer protect us from

  1. UV light

  2. meteorites

  3. infrred light

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The ozone layer absorbs harmful ultraviolet (UV) radiation from the sun, protecting living organisms on Earth. It does not protect against meteorites or infrared light. UV radiation can cause skin cancer and damage ecosystems.

Multiple choice

During which months is the Antarctic ozone hole visible?

  1. March to June

  2. February to April

  3. August to October

  4. September to December
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ozone hole is visible during the Antarctic spring, from September to early December, as strong westerly winds start to circulate around the continent and create an atmospheric container.

Multiple choice

Which of the following is the correct order of layers of atmosphere with respect to increase in distance from the earth?

  1. Troposhere – Stratosphere – Mesosphere – Exosphere – Thermosphere

  2. Troposhere – Stratosphere – Thermosphere – Exosphere – Mesosphere

  3. Troposhere – Stratosphere – Mesosphere – Thermosphere – Exosphere

  4. Troposhere – Stratosphere – Exosphere– Mesosphere – Thermosphere

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Troposphere: The layer of the atmosphere closest to the earth is the troposphere. It begins at the surface of the earth and extends to about 4-12 miles. The temperature of the troposphere decreases with height. This layer is known as the lower atmosphere. Stratosphere: Above the troposphere is the stratosphere, which extends to about 30-35 miles above the earth's surface. Temperature rises within the stratosphere, but still remains well below freezing. Mesosphere: From about 35 to 50 miles above the surface of the earth, lies the mesosphere, where the air is especially thin and molecules are great distances apart. Temperatures in the mesosphere reach a low of -184°F (-120°C). The stratosphere and the mesosphere are the middle atmosphere. Thermosphere: The thermosphere rises several hundred miles above the earth's surface, from 50 miles up to about 400 miles. Temperature increases with height and can rise to as high as 3,600°F (2000°C). Nonetheless, the air would be cold because the hot molecules are so far apart. This layer is known as the upper atmosphere. Exosphere: Extending from the top of the thermosphere to 6200 miles (10,000 km) above the earth is the exosphere. This layer has very few atmospheric molecules, which can escape into space.

Multiple choice

Consider the following statements:

  1. The amount of atmospheric ozone is measured by ‘Dobson Spectrometer’ and is expressed in Dobson unit.
  2. Chlorofluorocarbons are most likely to be present in photochemical smog.

Which of the given statements is/are true?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  1. The amount of atmospheric ozone is measured by ‘Dobson Spectrometer’ and is expressed in Dobson unit.
    1. Chlorofluorocarbons are most likely to be present in photochemical smog. Photochemical smog is a form of pollution that is caused by the reaction of sunlight with other pollutants such as hydrocarbons and nitrogen oxides. Photochemical smog can be seen sitting over the skylines of large cities and near factories.
Multiple choice

Which of the following statements about carbon di oxide is incorrect? a. It is transparent to the incoming solar radiation. b. It is opaque to the outgoing terrestrial radiation. c. It reflects back the terrestrial radiation towards the earth’s surface.

  1. Only a

  2. Only b

  3. Only c

  4. Only a and b

  5. Only b and c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This statement is incorrect. It absorbs a part of terrestrial radiation and reflects back some part of it towards the earth’s surface.

Multiple choice

From which of the following layers are the radio waves transmitted back to earth?

  1. Troposphere

  2. Stratosphere

  3. Thermosphere

  4. Mesosphere

  5. Exosphere
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ionosphere or thermosphere is located between 80 and 400 km above the mesopause. It contains electrically charged particles known as ions, and hence it is known as ionosphere. Radio waves transmitted from the earth are reflected back to the earth by this layer.