Atmosphere (World Geography)

Total Questions: 29

1. In the context of the mesosphere which of the following statements is NOT correct? [S.S.C. Online CHSI. (T-I) 12.10.2020 (Shift-I)]

Correct Answer: (b) Within the mesosphare, temperature increases with increasing height.
Solution:

The mesosphere is the third layer of the atmosphere, which extends from 50 km to 85 km altitude just above the stratosphere. The temperature in this layer of the atmosphere decreases continuously with an increase in altitude.

Key Facts About the Mesosphere:
  • Altitude Range: Approximately 50 km to 85 km (30 to 53 miles) above Earth's surface.
  • Temperature: This is the coldest layer of the atmosphere, with temperatures dropping to around -90°C (-130°F) at the top.

Key Features:

Meteors burn up in this layer due to friction with atmospheric particles.
It contains noctilucent clouds, which are the highest clouds in Earth’s atmosphere.

  • Air Pressure: Extremely low—only about 0.1% of sea level pressure.
  • Ozone: Unlike the stratosphere, the mesosphere does not contain significant ozone.
  • Scientific Challenge: It's one of the least studied layers because it's too high for balloons and too low for satellites.

What are Layers of Atmosphere? Structure, Importance

2. The ___________ layer starts at Earth's surface and extends 8 to 14.5 km high (5 to 9 miles). This part of the atmosphere is the densest and almost all weather is in this region. [Online CHSL (T-I) 15.10.2020 (Shift-I)]

Correct Answer: (a) Troposphere
Solution:

The troposphere extends from 8 to 14.5 km (5 to 9 mi) above the Earth's surface. This part of the atmosphere is the densest and almost all seasons occur in this region. The temperature in this zone decreases by 1°C for every 165 meters of altitude.

Extra Notes:
  • Commercial airplanes usually fly at the top of the troposphere or just above it (in the lower stratosphere) to avoid turbulence.
  • Temperature drops as you go higher in this layer.

3. Identify the element that is most prolific in the crust of the earth. [S.S.C. Online C.G.L. (T-I) 13.06.2019(Shift-I)]

Correct Answer: (c) Oxygen
Solution:Oxygen is the most abundant element in the Earth's outer layer because it is present in many compounds like various types of oxides, carbonates and silicates in rocks.

4. Ozone at the higher level of the atmosphere is a product of __________ acting on oxygen molecules. [S.S.C. Online C.G.L. (T-I) 6.03.2020 (Shift-II)]

Correct Answer: (c) UV radiation
Solution:

Ozone at the higher level of the atmosphere is a product of UV radiations acting on oxygen molecules.

How It Works:
  1. UV rays from the Sun strike an oxygen molecule (O₂).
  2. The energy splits the molecule into two separate oxygen atoms (O).
  3. Each free oxygen atom then combines with another O₂ molecule to form ozone (O₃).

This process occurs mainly in the stratosphere, forming the ozone layer that protects Earth from harmful UV radiation.

5. What are the gasses layers that surround the Earth called? [S.S.C. Online MTS (T-I) 17.09.2017 (Shift-I)]

Correct Answer: (b) Atmosphere
Solution:

The atmosphere is the layer of gases that surrounds Earth and is held in place by gravity. It is essential for life, weather, and climate on our planet.

Key Functions of the Atmosphere
  1. Protects life by blocking harmful ultraviolet (UV) radiation from the Sun.
  2. Traps heat (greenhouse effect) to maintain a livable temperature.
  3. Provides oxygen for respiration and carbon dioxide for photosynthesis.
  4. Enables weather and water cycle (rain, wind, clouds).
  5. Burns up meteors, protecting the Earth's surface.

6. Which of the following statements is not true about ozone? [S.S.C. Online MTS (T-I) 4.10.2017 (Shift-II)]

Correct Answer: (b) Ozone is stable near the earth's surface
Solution:

Ozone is a molecule made up of three oxygen atoms (O₃). It plays two very different roles depending on where it is found in Earth’s atmosphere.

Two Faces of Ozone: "Good Ozone" vs "Bad Ozone"
TypeLocationRole & Impact
Good OzoneStratosphere (10–50 km)Protects life by absorbing harmful UV radiation from the sun
Bad OzoneTroposphere (ground level)Acts as a pollutant, causing respiratory issues, smog, and plant damage

Formation:
  • Stratospheric Ozone: Formed naturally when UV light splits O₂ into individual atoms, which then combine with O₂ to form O₃.
  • Tropospheric Ozone: Formed when sunlight reacts with pollutants like nitrogen oxides (NOₓ) and volatile organic compounds (VOCs).
Health and Environmental Effects of Ground-Level Ozone:
  • Irritates lungs and throat
  • Worsens asthma and bronchitis
  • Damages crops and forests

7. Ultraviolet radiation in the stratosphere is absorbed by- [S.S.C. Online C.G.L(T-I) 31.08.2016 (Shift-II)]

Correct Answer: (b) Ozone
Solution:Ozone is the combination of three oxygen atoms into a single molecule (O). It is a gas produced naturally in the stratosphere, where it strongly absorbs incoming UV radiation

8. Which layer of the earth's atmosphere contains the ozone layer? [S.S.C. Online C.G.L.(T-I) 28.08.2016 (Shift-III), S.S.C. Online Constable GD 1.03.2019 (Shift-I)]

Correct Answer: (d) Stratosphere
Solution:

The ozone layer is located in the stratosphere, which is the second layer of Earth's atmosphere above the troposphere.

Stratosphere: 
  • Altitude: Approximately 15 to 50 km above Earth's surface
  • Contains the ozone layer, mainly between 20 to 30 km altitude
  • Function: Absorbs 95–99% of the Sun’s harmful ultraviolet (UV) radiation

9. Most of the atmospheric Ozone is found in which layer of atmosphere? [C.P.O. S.I. 6.06.2016 (Shift-I), S.S.C. Online CHSL (T-I) 12.10.2020 (Shift-II)]

Correct Answer: (c) Stratosphere
Solution:Ninety percent of the ozone in the atmosphere is occupied by the stratosphere, the layer of the atmosphere between about 10 and 50 kilometers altitude.

10. The Ozone layer is present in which atmospheric layer? [S.S.C. Online CHSL (T-I) 24.01.2017(Shift-III)]

Correct Answer: (c) Stratosphere
Solution:

The ozone layer is located in the stratosphere, which is the second layer of Earth's atmosphere above the troposphere.

Stratosphere:
  • Altitude: Approximately 15 to 50 km above Earth's surface
  • Contains the ozone layer, mainly between 20 to 30 km altitude
  • Function: Absorbs 95–99% of the Sun’s harmful ultraviolet (UV) radiation