Water Pollutants

Q. Which one of the following is not a bioindicator of water pollution?

1. Sewage fungus
2. Sludge worms
3. Bloodworms
4. Stone flies

Q.

Minamata disease is caused due to the presence of______in water.

1. Cadmium

2. Lead

3. Arsenic

4. ​​​​​​Mercury

Q. State whether true or false:
Most of the impurities in water are not visible to the naked eye.

1. True
2. False

Q. Oil spills cause water pollution in rivers.

1. True
2. False

Q. Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal wastewater into natural surface water is

1. <3.0 ppm
2. <10 ppm
3. <100 ppm
4. <30 ppm

Q. Dissolved oxygen in water decreases with an increase in the temperature of the water.

1. False
2. True

Q. Which of the following metals is a water pollutant?

1. As
2. Cu
3. Mg
4. Na

Q. A non-definite source of pollution is not hard to trace since it comes from a large area.

1. True
2. False

Q.

A major threat to ocean life comes from

1. Disposal of sewage

2. Oil spillage due to tanker accidents

3. Acid rains

4. Garbage disposal by ships

Q. A source of pollution not hard to trace since it is a result of accumulated pollution of a large area.

1. point
2. non-point
3. compound
4. spot