More than 70% of world's fresh water is contained in

1

(a)

polar ice

(b)

glaciers and mountains

(c)

Antarctica

(d)

Greenland

Which one of the following statements pertaining to pollutants is correct?

1

(a)

DDT is a non-biodegradable pollutant

(b)

excess fluoride in drinking water causes osteoporosis.

(c)

excess cadmium in drinking water causes black foot disease.

(d)

methyl mercury in water may cause 'Itai Itai' disease.

In a coal fired power plant electrostatic precipitators are installed to control emission of

1

(a)

NO_X

(b)

SPM

(c)

CO

(d)

SO₂

Ozone is spread in the swimming pool because

1

(a)

it acts as disinfectant

(b)

it absorbs UV radiations

(c)

ozone is easily available from O₂

(d)

all of the above

Which one of the following is the correct percentage of the two green house gases that contribute to the total global warming?

1

(a)

N₂O 6%, CO₂ 86%

(b)

methane 20%, N₂O 18%

(c)

CFCs 14%, methane 20%

(d)

CO₂ 40%, CFCs 30%

A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this.
(a) lots of urea and phosphate fertilizers were used in the crops in the vicinity
(b) the area was sprayed with DDT by an aircraft
(c) the lake water turned green and stinky
(d) phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis
Which two of the above were main reasons of fish mortality in the lake?

1

(a)

A, C

(b)

A, B

(c)

B, C

(d)

C, D

Photochemical smog is caused by a light mediated reaction between

1

(a)

NO₂ and unsaturated hydrocarbons

(b)

NO₂ and O₃

(c)

SO₂ and unburnt hydrocarbons

(d)

SO₂ and O₃

Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change unburnt hydrocarbons into:

1

(a)

carbon dioxide and water

(b)

carbon monoxide

(c)

methane

(d)

carbon dioxide and methene

Nuisance growth of aquatic plants and bloom-forming algae in natural waters is generally due to high concentration of:

1

(a)

carbon

(b)

sulphur

(c)

calcium

(d)

phosphorus

Algal blooms impart a distinct colour to water due to:

1

(a)

their pigments

(b)

excretion of coloured substances 

(c)

formation of coloured chemicals in water facilitated by physiological degradation of algae. 

(d)

absorption of light by algal cell wall.