NCERT Class-9 Science Solutions: Chapter 14-Natural Resources Part 2 (For CBSE, ICSE, IAS, NET, NRA 2022)

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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?

1. They are eco-friendly
2. They turn the fields barren after some time
3. They adversely affect the useful component from the soil
4. They destroy the soil fertility

Answer: A

Question 9:

The nitrogen molecules present in air can be converted into nitrates and nitrites by

1. A biological process of nitrogen fixing bacteria present in soil
2. A biological process of carbon fixing factor present in soil
3. Any of the industries manufacturing nitrogenous compounds
4. The plants used as cereal crops in field

Answer: A

Question 10:

One of the following processes is not a step involved in the water-cycle operating in nature

1. Evaporation
2. Transpiration
3. Precipitation
4. Photosynthesis

Answer: D

Question 11:

The term “water-pollution” can be defined in several ways. Which of the following statements does not give the correct definition?

1. The addition of undesirable substances to water-bodies
2. The removal of desirable substances from water-bodies
3. A change in pressure of the water-bodies
4. A change in temperature of the water-bodies

Answer: C

Question 12:

Which of the following is not a greenhouse gas?

1. Methane
2. Carbon dioxide
3. Carbon monoxide
4. Ammonia

Answer: D

Question 13:

Which step is not involved in the carbon-cycle?

1. Photosynthesis
2. Transpiration
3. Respiration
4. Burning of fossil fuels

Answer: B

Question 14:

‘Ozone-hole’ means

1. A large sized hole in the ozone layer
2. Thinning of the ozone layer
3. Small holes scattered in the ozone layer
4. Thickening of ozone in the ozone layer

Answer: B