The ‘thickness’ of Stratospheric Ozone layer is measured in/on:
1. Sieverts units
2. Dobson units
3. Melson units
4. Beaufort Scale

The lowest layer of earth's atmosphere is :

1. troposphere

2. stratosphere

3. mesophere

4. ionosphere

Ozone depletion in the stratosphere is mainly caused by:

1. SO₂

2. NO₂

3. NO

4. chlorofluorocarbons

Gas that is not a pollutant is : 

1. Carbon monoxide

2. Nitrogen peroxide

3. Carbon dioxide

4. Sulphur dioxide

Air pollution from the leakage of methyl isocyanate gas from the union carbide factory in Bhopal caused a major tragedy on:

1. Dec. 2, 1984

2. Dec 15, 1983

3. Dec.10, 1982

4. Dec. 4, 1988

Eutrophication of a lake means, it:

1. is low in nutrients

2. is high in nutrients

3. has a high temperature

4. has an lesser amount of organic matter

Which of the following gases present in air protects life on the earth from the harmful effects of UV rays from the sun?

1. Carbon dioxide

2. Nitrogen

3. Oxygen

4. Ozone

In the upper layer of the atmosphere, ozone is formed by the :

1. action of UV rays on oxygen

2. combination of oxygen molecules

3. action of electric discharge of oxygen molecules

4. effect of high pressures on oxygen

A fertile soil is likely to have a pH of :

1. 3

2. 9

3. 6-7

4. 14

Which country has the greatest contribution for the hole formation in ozone layer?

1. Russia

2. Japan

3. USA

4. Germany