Photochemical smog does not contain
1. PAN
2. Ozone
3. Nitrogen dioxide
4. ${\mathrm{CO}}_2$

In which one of the following the BOD (Biochemical oxygen demand) of sewage (s), distellary effluent(DE), paper mill effluent (PE) and sugarmill effluent (SE) have been arranged in ascending order.
1. SE < PE < S < DE
2. PE < S < SE < DE
3. S < DE < PE < SE
4. SE < S < PE < DE

In coal fired power plants, electrostatic precipitators are fitted to control emission of:
1. ${\mathrm{NO}}_{\mathrm{x}}$
2. CO
3. SPM
4. ${\mathrm{SO}}_2$

Which is correct
1. Both Azotobacter and Rhizobium fix atmospheric nitrogen in root nodules of plants
2. Cyanobacteria, Anabaena and Nostoc are mobilizers of phosphates and plant nutrition in soil
3. At present it is not possible to grow maize without chemical fertilizers
4. excessive use of chemical fertilizers may lead to eutrophication of nearby water bodies

Which is not a bio indicator of water pollution
1. Blood worms
2. Stone flies
3. Sewage fungus
4. Sludge worms.

Which one of the following is correct percentage of the two (out of the total of 4) green house gases tocontribute to the total global warming.
1. ${\mathrm{N}}_2\mathrm{O}$ 6%, ${\mathrm{CO}}_2$ 86 %
2. Methane 20% , ${\mathrm{N}}_2\mathrm{O}$ 18%
3. ${\mathrm{CO}}_2$ 40%, CFC 30%
4. CFCs 14%, methane 20%

According to Central Pollution Control Board (CPCB), Which particulate size in diameter (in
micrometres) of the air pollutants is responsible for greatest harm to human health
1. 1•0 or less
2. 5•2-2•5
3. 2•5 or less
4. 1•5 or less

Montreal Protocol aims at
1. Control of ${\mathrm{CO}}_2$ emission
2. Reduction of ozone depleting substances
3. Biodiversity conservation
4. Control of water pollution

Chipko movement was launched for the protection of
1. Wet Lands
2. Grasslands
3. Forests
4. Livestock

The two gases making the highest relative contribution to the greenhouse gases are:
1. ${\mathrm{CH}}_4$ and ${\mathrm{N}}_2\mathrm{O}$
2. CFCs and ${\mathrm{N}}_2\mathrm{O}$
3. ${\mathrm{CO}}_2$ and ${\mathrm{N}}_2\mathrm{O}$ 
4. ${\mathrm{CO}}_2$ and ${\mathrm{CH}}_4$