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

Doorsteptutor material for CBSE/Class-9 Science is prepared by world's top subject experts: fully solved questions with step-by-step explanation- practice your way to success.

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 & 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

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

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

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

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