Pollution can be controlled by-

1. Sewage treatment.

2. Checking atomic blasts.

3. Manufacturing electrically operated vehicles.

4. All of the above.

The main factor of water pollution is:

1. Smoke

2. Industrial waste

3. Detergent

4. Ammonia

When a lake get covered with algae, a stinking smell comes out and its water becomes unpotable. The reason for such a condition of the lake is-

1. Eutrophication.

2. Excess of oxalate ions in water.

3. Excess of non-biodegradable waste in water.

4. Excess of photosynthesis.

A farmer was told that fishes were not fit for human consumption because a large amount of pesticides had accumulated in the tissues of fishes. This happens:

1. By the transfer of pesticides in the food chain.

2. By the degradation of pesticides.

3. By the reaction of pesticides with atmospheric oxygen.

4. By the reaction of pesticides with atmospheric carbon dioxide.

If a lake is contaminated with DDT, it's highest concentration would be found in :

1. Primary consumer

2. Secondary consumer

3. Tertiary consumer

4. None of the above.

Mercury, aluminum, lead, copper, DDT, etc. are an example of :

1. Biodegradable Pollutant.

2. Non-biodegradable pollutant.

3. Non pollutant.

4. Noise pollutant.

If water pollution continues at its present rate, it will eventually :

1. Stop the water cycle.

2. Prevent precipitation.

3. Make oxygen molecules unavailable to water plants.

4. Make nitrate molecules unavailable to water plants.

Match the pollutant (s) in Column I with effect (s) in Column II.

Codes

The major contributor to water pollution among the following is- 

1. Sound

2. ${\mathrm{SO}}_2$

3. Salts of arsenic

4. Sewage