The main factor of water pollution is:

1. Smoke

2. Industrial waste

3. Detergent

4. Ammonia

The major contributor to water pollution among the following is- 

1. Sound

2. ${\mathrm{SO}}_2$

3. Salts of arsenic

4. Sewage

Which of the following atmospheric pollutants is not produced by the exhaust of motor vehicle in Delhi

(1) $S{O}_2$

(2) Hydrocarbon gases

(3) Fly ash

(4) CO

Pollution can be controlled by

(1) Sewage treatment

(2) Checking atomic blasts

(3) Manufacturing electrically operated vehicles

(4) All the above

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

(1) Stop water cycle

(2) Prevent precipitation

(3) Make oxygen molecules unavailable to water plants

(4) Make nitrate molecules unavailable to water plants

In cities like Bombay and Calcutta, the major air pollutants are

(1) Ozone

(2) Carbon monoxide and oxides of Sulphur

(3) Hydrocarbons and not air

(4) Algal spores and marsh gas

Recent reports of acid rains industrial cities are due to the effect of atmospheric pollution by

(1) Excessive release of $N{O}_2 and S{O}_2$ by burning of fossil fuels.

(2) Excessive release of $C{O}_2$ by burning of fuel like wood and charcoal, cutting of forests and increased  animal population.

(3) Excessive release of $N{H}_3$  by industrial plants and coal gas.

(4) Excessive release of CO in atmosphere by incomplete combustion of cock, charcoal and other carbonaceous fuels in pancity of oxygen.

Pollution is a change in physical, chemical or biological characters of our land and water that may be

(1) Desirable and harmful to human

(2) Desirable and useful to a human

(3) Undesirable and harmful to human

(4) undesirable and useful to a human

Which is the greatest air pollutant these days

(1) Factories

(2) Motor vehicles

(3) Domestic appliances

(4) animals

Removal of the soil by the action of wind and water is known as

(1) Erosion

(2) Fossilization

(3) Leaching

(4) Calcification