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?

  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

Image fertilizers and pesticides hramful effect of soil

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

  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

Image nitrogen molecules

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

  1. Evaporation

  2. Transpiration

  3. Precipitation

  4. Photosynthesis

Answer: D

Image the water cycle

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?

  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

Image greenhouse gas

Image Greenhouse Gas

Image greenhouse gas

Question 13:

Which step is not involved in the carbon-cycle?

  1. Photosynthesis

  2. Transpiration

  3. Respiration

  4. Burning of fossil fuels

Answer: B

Image the carbon-cycle

Image the Carbon-Cycle

Image the carbon-cycle

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

Image the Ozone-hole

Image the Ozone-Hole

Image the Ozone-hole