NCERT Class-9 Science Solutions: Chapter 14-Natural Resources Part 2
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Question 8:
Among the given options, which one is not correct for the use of large amount of fertilizers and pesticides?
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They are eco-friendly
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They turn the fields barren after some time
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They adversely affect the useful component from the soil
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They destroy the soil fertility
Answer: A

Image Fertilizers and Pesticides Hramful Effect of Soil
Image fertilizers and pesticides hramful effect of soil
Question 9:
The nitrogen molecules present in air can be converted into nitrates and nitrites by
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A biological process of nitrogen fixing bacteria present in soil
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A biological process of carbon fixing factor present in soil
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Any of the industries manufacturing nitrogenous compounds
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The plants used as cereal crops in field
Answer: A

Image Nitrogen Molecules
Image nitrogen molecules
Question 10:
One of the following processes is not a step involved in the water-cycle operating in nature
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Evaporation
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Transpiration
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Precipitation
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Photosynthesis
Answer: D

Image the Water Cycle
Image the water cycle
Question 11:
The term “water-pollution” can be defined in several ways. Which of the following statements does not give the correct definition?
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The addition of undesirable substances to water-bodies
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The removal of desirable substances from water-bodies
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A change in pressure of the water-bodies
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A change in temperature of the water-bodies
Answer: C
Question 12:
Which of the following is not a greenhouse gas?
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Methane
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Carbon dioxide
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Carbon monoxide
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Ammonia
Answer: D

Image Greenhouse Gas
Image greenhouse gas
Question 13:
Which step is not involved in the carbon-cycle?
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Photosynthesis
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Transpiration
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Respiration
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Burning of fossil fuels
Answer: B

Image the Carbon-Cycle
Image the carbon-cycle
Question 14:
‘Ozone-hole’ means
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A large sized hole in the ozone layer
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Thinning of the ozone layer
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Small holes scattered in the ozone layer
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Thickening of ozone in the ozone layer
Answer: B

Image the Ozone-Hole
Image the Ozone-hole