Question

29. Ozone present in ________ plays a vital role in protecting the life on earth's surface from harmful UV rays.

• A. troposphere
• B. stratosphere
• C. mesosphere
• D. ionosphere

Answer 1

The correct option is B

stratosphere

Explanation for correct option:

Option (B):

• The stratosphere is the layer of the atmosphere above the troposphere and extends up to 50 km above the surface of the earth.
• The ozone layer is present in the stratosphere and absorbs harmful ultraviolet (UV) radiation. Thus, protects us from these harmful rays.

Explanation for incorrect options:

Option (A): Troposphere extends up to 20 km above the surface of the earth. The maximum percentage of the total mass of the atmosphere is present in the troposphere.

Option (C): Mesosphere is the layer above the stratosphere and extends up to 85 km above the surface of the earth.

Option (D): The ionosphere or thermosphere extends up to 690-950 km above the surface of the earth. It is also called the upper atmosphere.

Hence, option (B) is the correct answer.