A scrubber in the exhaust of a chemical industrial plant removes:

1. Gases like sulphur dioxide

2. Particulate matter of the size 5 micrometer or above

3. Gases like ozone and methane

4. Particulate matter of the size 2.5 micrometer or less

Global warming can be controlled by:

In an area where DDT had been used extensively, the population of birds declined significantly because:
1. Birds stopped laying eggs
2. Earthworms in the area got eradicated
3. Cobras were feeding exclusively on birds
4. Many of the birds laid eggs, but the eggs did not hatch

Which one of the following is a wrong statement?

Which one of the following pairs of gases are the cause of 'Greenhouse effect'?

1. ${\mathrm{CO}}_2$ $\mathrm{and}$ $\mathrm{CO}$

2. ${\mathrm{CFC}}_{\mathrm{s}}$ $\mathrm{and}$ ${\mathrm{SO}}_2$

3. ${\mathrm{CO}}_2$ $\mathrm{and}$ ${\mathrm{N}}_2\mathrm{O}$

4. ${\mathrm{CO}}_2$ $\mathrm{and}$ ${\mathrm{O}}_3$

dB is a standard abbreviation used for the quantitative expression of:

1. the density of bacteria in a medium

2. a particular pollutant

3. the dominant Bacillus in a culture

4. a certain pesticide

The two gases making the highest relative contribution to the greenhouse gases are:

1. $C{O}_2$ $and$ $C{H}_4$

2. $C{H}_4$ $and$ $$ $N{O}_2$

3. $\mathrm{CFCs}$ $\mathrm{and}$ ${\mathrm{N}}_2\mathrm{O}$

4. $C{O}_2$ $and$ $N_{2}O$

Chipko movement was launched for the protection of:

1. grasslands

2. forests

3. livestock

4. wet lands

Montreal protocol aims at:

1. reduction of ozone depleting substances

2. biodiversity conservation

3. control of water pollution

4. control of CO₂ emission

Biochemical Oxygen Demand (BOD) in river water: