Question

The Ozone gas found in which of the following layers of the atmosphere absorbs harmful UV radiations and prevents them from reaching the earth's surface?
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere

Answer 1

Correct Answer - Option 2 : Stratosphere

The correct answer is Stratosphere.

Stratosphere

• The stratosphere is the second-lowest layer of Earth's atmosphere and extends up to about 50 km.
• The ozone layer is found in Stratosphere.
• The part of the Stratospherein which there is a concentration of ozone is called the ozonosphere and it absorbs UV radiation from the atmosphere.
• In the stratosphere, temperature increases with altitude.
• The stratosphere is free from dust particles and also from atmospheric turbulences.
• The stratosphere is ideal for flying of jet aircraft.
• The line which separates the stratosphere and the mesosphere is the Stratospause.

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Troposphere

• The troposphere is the lowest layer of Earth's atmosphere and extends up to about 18 km.
•  The troposphere is thinner in poles and thicker at the equator.
• In the troposphere, temperature decreases with altitude.
• This layer accounts for practically the entire water vapour, all dust particles, and most of the carbon dioxide contained in the atmosphere. Due to this all-weather phenomena such as condensation, precipitation and storms occurs
• The line which separates the troposphere and the stratosphere is the tropopause.

​Mesosphere

• The mesosphere is the third layer of Earth's atmosphere and extends up to about 80 km.
• In the mesosphere, temperature decreases with altitude.
• The mesosphere is the coldest part of the atmosphere.
• The line which separates the mesosphere and the thermosphere is the Mesospause.

​Thermosphere

• The thermosphere is the fourth layer of Earth's atmosphere and extends up to about 600 km.
• The thermosphere is also called Ionosphere. 
• Due to the large concentration of ionized particles in this layer the ionosphere acts as a protective layer against meteorites, that are burnt in this layer.
• In the thermosphere, temperature increases with altitude.
• Radio waves are found in the thermosphere.
• The upper part of the thermosphere contains only lighter gases like Helium and Hydrogen.
• Gravitational force is very less in the thermosphere.
• Thermopause is the upper part of the thermosphere.