In a water body polluted with biodegradable organic compounds,
1. the BOD and DO content are low
2. the BOD and DO content are high
3. the BOD is low and DO content is high
4. the BOD is high and DO content is low

The world’s most problematic aquatic weed, “The terror of Bengal”, is the name given to:

An increase in concentration of the intoxicant at successive trophic levels is known as:

High concentrations of accumulated DDT in birds:
1. kills pathogens in their blood
2. causes sterility by affecting gametogenesis
3. leads to premature breaking of eggs
4. causes spasticity of the muscles of the body

What was added in 1987 as a pollutant to The Air (Prevention and Control of Pollution) Act, [originally passed in 1981]?
1. radioactive wastes
2. CFCs
3. ground level ozone
4. noise

Which of the following statements is not true regarding CNG?
1. It is non-polluting
2. It burns more efficiently than petrol and diesel
3. It cannot be siphoned off by thieves
4. It cannot be adulterated

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 and 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

The device, normally used to remove gaseous pollutants from polluted air but can remove large particulate matter as well, is:
1. electrostatic precipitator

2. cyclonic separator

3. trajectory separator

4. Scrubber

In an algal bloom, the cause of death of other algae is usually:
1. toxins

2. decreased DO

3. decreased sunlight

4. decreased nutrients