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| 11. |
The largest source of pollution in the world is: |
| A. |
Industrial effluents |
B. |
Sewage and garbage |
| C. |
Automobile exhausts |
D. |
Herbicides and insecticides |
Answer: Option B
Explanation:
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| 12. |
"Green Hose Effect" means: |
| A. |
Pollution in houses |
B. |
Prevention of ultraviolet rays |
| C. |
Trapping of solar energy due to atmospheric carbon dioxide |
D. |
None of these |
Answer: Option C
Explanation:
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| 13. |
The maximum fixation of solar energy is done by: |
| A. |
Bacteria |
B. |
Protozoa |
| C. |
Green plants |
D. |
Fungi |
Answer: Option C
Explanation:
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| 14. |
Biodegradable wastes can usually be converted into useful substances with the help of: |
| A. |
Bacteria |
B. |
Nuclear proteins |
| C. |
Radioactive substances |
D. |
None of these |
Answer: Option A
Explanation:
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| 15. |
Which of the following gases is not found free in air? |
| A. |
Nitrogen |
B. |
Hydrogen |
| C. |
Oxygen |
D. |
Carbon dioxide |
Answer: Option B
Explanation:
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| 16. |
Nitrogen fixation is done by: |
| A. |
Red algae |
B. |
Blue green algae |
| C. |
Brown algae |
D. |
None of these |
Answer: Option B
Explanation:
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| 17. |
A microscopic organism playing a vital role in nitrogen cycle is: |
| A. |
Virus |
B. |
Bacteria |
| C. |
Protozoa |
D. |
Red algae |
Answer: Option B
Explanation:
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| 18. |
Which of the following fuels causes minimum environmental pollution? |
| A. |
Diesel |
B. |
Kerosene |
| C. |
Hydrogen |
D. |
Coal |
Answer: Option C
Explanation:
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| 19. |
The crop most susceptible to frost is: |
| A. |
Wheat |
B. |
Cotton |
| C. |
Red gram |
D. |
Black gram |
Answer: Option A
Explanation:
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| 20. |
The fain factor which determines the balance of nature is: |
| A. |
Human activities |
B. |
Habit and habitat |
| C. |
Environmental pollution |
D. |
Availability of food |
Answer: Option A
Explanation:
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