According to the Central Pollution Control Board [CPCB] what size (in diameter) of particulate is responsible for causing greater harm to human health?

1. 3.5 micrometers

2. 2.5 micrometers

3. 4.0 micrometers

4. 3.0 micrometers

When domestic sewage mixes with river water:

''Good ozone'' is found in the:
1. Ionosphere
2. Mesosphere
3. Troposphere
4. Stratosphere

Consider the following statements (A-D) about organic farming:
 

Which of the above statements is correct?
1. (A) and (B) only 
2. (B), (C) and (D)
3. (C) and (D) only 
4. (B) and (C) only

Air (Prevention and Control of Pollution) Act was amended in 1987 to include among pollutants:

1. Vehicular exhaust

2. Allergy causing pollen

3. Noise

4. Particulates of size 2.5 micrometer or below

A species that was introduced for ornamentation but has become a troublesome weed in India:

1. Parthenium hysterophorus

2. Eichhornia crassipes

3. Prosopis juliflora

4. Trapa Spinosa

If $C{O}_2$ is absent in the atmosphere of the earth, then:
1.  Temperature will decrease
2.  Temperature will increase
3.  Plants will flourish well
4.  No effect

Besides CH₄ and CO₂, another green house gas is:
1.   SO₂
2.   NH₃
3.   N₂O
4.   CFC 

Temperature variation in Pacific ocean in present time is called:
1.  Cyclone effect
2.  El Nino effect
3.  Greenhouse effect
4.  Gaudikov's effect

Sewage purification is performed by:
1.  Microbes
2.  Fertilisers
3.  Antibiotics
4.  Antiseptics