Forum

Natural Resources

Top-soil contains the following
(a) Humus and living organisms only
(b) Humus and soil particles only
(c) Humus, living organisms and plants
(d) Humus, living organisms and soil particles

05/11/2024

Science

9th

Natural Resources

Which of the following is a recently originated problem of environment?
(a) Ozone layer depletion
(b) Green house effect
(c) Global warming
(d) All of the above

05/11/2024

Science

9th

Natural Resources

Ozone-layer is getting depleted because of
(a) excessive use of automobiles
(b) excessive formation of industrial units
(c) excessive use of man-made compounds containing both fluorine and
chlorine
(d) excessive deforestation

05/11/2024

Science

9th

Natural Resources

‘Ozone-hole’ means
(a) a large sized hole in the ozone layer
(b) thinning of the ozone layer
(c) small holes scattered in the ozone layer
(d) thickening of ozone in the ozone layer

05/11/2024

Science

9th

Natural Resources

Which step is not involved in the carbon-cycle?
(a) Photosynthesis
(b) Transpiration
(c) Respiration
(d) Burning of fossil fuels

05/11/2024

Science

9th

Natural Resources

Which of the following is not a green house gas?
(a) Methane
(b) Carbon dioxide
(c) Carbon monoxide
(d) Ammonia

05/11/2024

Science

9th

Natural Resources

The term “water-pollution” can be defined in several ways. Which of the
following statements does not give the correct definition?
(a) The addition of undesirable substances to water-bodies
(b) The removal of desirable substances from water-bodies
(c) A change in pressure of the water bodies
(d) A change in temperature of the water bodies

05/11/2024

Science

9th

Natural Resources

One of the following processes is not a step involved in the water-cycle
operating in nature
(a) evaporation
(b) transpiration
(c) precipitation
(d) photosynthesis

05/11/2024

Science

9th

Natural Resources

The nitrogen molecules present in air can be converted into nitrates and
nitrites by
(a) a biological process of nitrogen fixing bacteria present in soil
(b) a biological process of carbon fixing factor present in soil
(c) any of the industries manufacturing nitrogenous compounds
(d) the plants used as cereal crops in field

05/11/2024

Science

9th

Natural Resources

Among the given options, which one is not correct for the use of large
amount of fertilisers and pesticides?
(a) They are eco-friendly
(b) They turn the fields barren after some time
(c) They adversally affect the useful component from the soil
(d) They destroy the soil fertility

05/11/2024

Science

9th