Question

Ozone hole refers to

• A. increase concentration of ozone in the atmosphere
• B. decrease of thickness of ozone in troposphere
• C. decrease in thickness of ozone layer in stratosphere
• D. black hole

Answer 1

The correct option is C

decrease in thickness of ozone layer in stratosphere

The explanation for the correct option:

• Ozone is an allotrope of oxygen that is found in the upper layer of the atmosphere (stratosphere) about 20 Km away from the surface of the earth. It protects the earth's surface from UV radiation. These radiations cause skin cancer in humans.
• A decrease in the quantity of ozone in the stratosphere is called depletion in the ozone layer or the ozone hole.

Chlorofluorocarbon compounds (CFCs), oxides of nitrogen, etc., obtained from various human activities cause depletion of the ozone layer.

Thus option (C) i.e., ozone hole refers to the decrease in thickness of the ozone layer in the stratosphere.