According to CPCB, what particulate size is most harmful to humans:
1. more than 10 micrometers
2. between 5 to 10 micrometers
3. between 2.5 to 5 micrometers
4. less than 2.5 micrometers

The most effective device to remove particulate matter from polluted air is:
1. electrostatic precipitator
2. cyclonic separator
3. trajectory separator
4. scrubber

A catalytic converter :
1. reduces unburnt hydrocarbon in auto emissions
2. converts NOx to nitrogen
3. reduces lead in the exhaust
4. converts carbon dioxide to carbon monoxide

The concentration of ozone in stratosphere is normally lowest during the period:-

1. February - April

2. May - July

3. July - October

4. November - January

Which of the following radiatively active gases contributes the least to global warming?

1. CO₂

2. CFC

3. N₂O

4. CH₄

To safeguard our water resources, the Water (Prevention and Control of Pollution) Act, was passed in:

1. 1951
2. 1974
3. 1985
4. 1987

Eventually, the only solution for the treatment of e-wastes, provided it is carried out in an environment friendly manner, is:
1. Incineration
2. Burying in landfill sites
3. Dumping in developing countries
4. Recycling

Match each item in Column I with one item in Column II and choose the correct answer from the code given below:

           COLUMN I                                                                  COLUMN II
A. Air [Prevention and Control of Pollution] Act                          a. 1981
B. Water [Prevention and Control of Pollution] Act                     b. 1974
C. Environment [Protection] Act                                               c. 1986
D. Montreal Protocol                                                               d. 1987

Codes:
             A.            B.                   C.              D.
1.          a              b                    c               d

2.          b              a                    d               c

3.          d              c                    b               a

4.          c              d                    a               b

Pollution:
1. Any undesirable change in physical characteristics of air, land water and soil
2. Any undesirable change in biological characteristics of air, land water and soil
3. Any undesirable change in physical, chemical and biological characteristics of air, land water and soil
4. Any undesirable change in physical and chemical characteristics of air, land water and soil

Agents that bring undesirable change in biological, physical and chemical environment is called