13
MCQ (Multiple Correct Answer)
Which of the following conditions shows the polluted environment?
A
pH of rain water is 5.6
B
Amount of carbon dioxide in the atmosphere is $0.03 \%$
C
Biochemical oxygen demand 10 ppm
D
Eutrophication
14
MCQ (Multiple Correct Answer)
Phosphate containing fertilisers cause water pollution. Addition of such compounds in water bodies causes ............... .
A
enhanced growth of algae
B
decrease in amount of dissolved oxygen in water
C
deposition of calcium phosphate
D
increase in fish population
15
MCQ (Multiple Correct Answer)
The acids present in acid rain are ............. .
A
PeroxyacetyInitrate
B
$\mathrm{H}_2 \mathrm{CO}_3$
C
$\mathrm{NHO}_3$
D
$\mathrm{H}_2 \mathrm{SO}_4$
16
MCQ (Multiple Correct Answer)
The consequences of global warming may be .......... .
A
increase in average temperature of the earth
B
melting of Himalayan Glaciers
C
increased biochemical oxygen demand
D
eutrophication
17
Subjective
Green house effect leads to global warming. Which substances are responsible for green house effect?
Explanation
The various gases which bring green house effect responsible for global warming are the following with relative contributions
| Various gases | Relative contribution |
|---|---|
| Carbon dioxide | 50% |
| Water vapour | 2% |
| Nitrous oxide | 4% |
| Ozone | 8% |
| Chlorofluorocarbons | 17% |
| Methane | 19% |