Choose the correct option:<\/span><\/p>\nQuestion 1.
\nThe atmosphere of the earth is heated by radiations which are mainly
\n(a) radiated by the sun
\n(b) re-radiated by land
\n(c) re-radiated by water
\n(d) re-radiated by land and water
\nAnswer:
\n(d) re-radiated by land and water<\/p>\n
Question 2.
\nIf there were no atmosphere around the earth, the temperature of the earth will
\n(a) increase
\n(b) go on decreasing
\n(c) increase during day and decrease during night
\n(d) be unaffected
\nAnswer:
\n(c) increase during day and decrease during night<\/p>\n
<\/p>\n
Question 3.
\nWhat would happen, if all the oxygen present in the environment is converted to ozone?
\n(a) We will be protected more
\n(b) It will become poisonous and kill living forms
\n(c) Ozone is not stable, hence it will be toxic
\n(d) It will help harmful sun radiations to reach earth and damage many life forms.
\nAnswer:
\n(b) It will become poisonous and kill living forms<\/p>\n
Question 4.
\nOne of the following factors does not lead to soil formation in nature
\n(a) the sun
\n(b) water
\n(c) wind
\n(d) polythene bags
\nAnswer:
\n(d) polythene bags<\/p>\n
Question 5.
\nThe two forms of oxygen found in the atmosphere are
\n(a) water and ozone
\n(b) water and oxygen
\n(c) ozone and oxygen
\n(d) water and carbon-dioxide
\nAnswer:
\n(c) ozone and oxygen<\/p>\n
Question 6.
\nThe process of nitrogen-fixation by bac\u00acteria does not take place in the presence of
\n(a) molecular form of hydrogen
\n(b) elemental form of oxygen
\n(c) water
\n(d) elemental form of nitrogen
\nAnswer:
\n(b) elemental form of oxygen<\/p>\n
Question 7.
\nRainfall patterns depend on
\n(a) the underground water table
\n(b) the number of water bodies man area
\n(c) the density pattern of human population in an area
\n(d) the prevailing season in an area
\nAnswer:
\n(b) the number of water bodies man area<\/p>\n
<\/p>\n
Question 8.
\nAmong the given options, which one is not correct for the use of large amount of fertilisers and pesticides?
\n(a) They are eco-friendly
\n(b) They turn the fields barren after some time
\n(c) They adversely affect the useful component from the soil
\n(d) They destroy the soil fertility
\nAnswer:
\n(a) They are eco-friendly<\/p>\n
Question 9.
\nThe nitrogen molecules present in air can be converted into nitrates and nitrites by
\n(a) a biological process of nitrogen fixing bacteria present in Soil
\n(b) a biological process of carbon fixing factor present in soil
\n(c) any of the industries manufacturing nitrogenous compounds
\n(d) the plants used as cereal crops in field
\nAnswer:
\n(a) a biological process of nitrogen fixing bacteria present in Soil<\/p>\n
Question 10.
\nOne of the following processes is not a step involved in the water-cycle operating in nature
\n(a) evaporation
\n(b) transpiration
\n(c) precipitation
\n(d) photosynthesis
\nAnswer:
\n(d) photosynthesis<\/p>\n
Question 11.
\nThe term “water-pollution” can be defined in several ways. Which of the following statements does not give the correct definition?
\n(a) The addition of undesirable substances to water-bodies
\n(b) The removal of desirable substances from water-bodies
\n(c) A change in pressure of the water bodies
\n(d) A change in temperature of the water bodies
\nAnswer:
\n(c) A change in pressure of the water bodies<\/p>\n
Question 12.
\nWhich of the following is not a greenhouse gas?
\n(a) Methane
\n(b) Carbon dioxide
\n(c) Carbon monoxide
\n(d) Ammonia
\nAnswer:
\n(d) Ammonia<\/p>\n
Question 13.
\nWhich step is not involved in the carbon-cyicle?
\n(a) Photosynthesis
\n(b) Transpiration
\n(c) Respiration
\n(d) Burning of fossil fuels
\nAnswer:
\n(b) Transpiration<\/p>\n
<\/p>\n
Question 14.
\n‘Ozone-hole’ means
\n(a) a large sized hole in the ozone layer
\n(b) thinning of the ozone layer
\n(c) small holes scattered in the ozone layer
\n(d) thickening of ozone in the ozone layer
\nAnswer:
\n(b) thinning of the ozone layer<\/p>\n
Question 15.
\nOzone-layer is getting depleted because of
\n(a) excessive use of automobiles
\n(b) excessive formation of industrial units
\n(c) excessive use of man-made compounds containing both fluorine and chlorine
\n(d) excessive deforestation.
\nAnswer:
\n(c) excessive use of man-made compounds containing both fluorine and chlorine<\/p>\n
Question 16.
\nWhich of the following is a recently originated problem of environment?
\n(a) Ozone layer depletion
\n(b) Greenhouse effect
\n(c) Global warming
\n(d) All of the above<\/p>\n
Very Short Answer Questions<\/span><\/p>\nQuestion 1.
\nDefine the term natural resource.
\nAnswer:
\nAny useful material obtained from the nature is called a natural resource.<\/p>\n
Question 2.
\nWhat are two types of natural resources?
\nAnswer:
\nThe two types of natural resources are renewable resources and non-renewable resources.<\/p>\n
Question 3.
\nWhich zone of atmosphere is the closet to the earth?
\nAnswer:
\nTroposphere<\/p>\n
Question 4.
\nName the three important constituents of the air.
\nAnswer:
\nThe three important constituents of soil are nitrogen, oxygen and carbon dioxide.<\/p>\n
Question 5.
\nWhere on earth the British researchers have found the ozone hole in 1985?
\nAnswer:
\nOver South Antarctica.<\/p>\n
<\/p>\n
Question 6.
\nMontreal protocol in 1986 had banned on the emission of a pollutant to protect the ozone layer. Name the pollutant.
\nAnswer:
\nMontreal protocol had banned the emission of CFCs (Chlorofluro carbon)<\/p>\n
Question 7.
\nName some of the greenhouse gases.
\nAnswer:
\nCarbon dioxide, methane, sulphur dioxide and CFCs.<\/p>\n
Question 8.
\nWhich two types of components are found in biosphere?
\nAnswer:
\nBiotic (living) components and abiotic (Non-living) components.<\/p>\n
Question 9.
\nList the factors which contribute to the weathering of rocks in soil formation.
\nAnswer:
\nThe factors are temperature, air, water and living organisms like lichens.<\/p>\n
Question 10.
\nWhich factor is responsible for deciding the type of soil?
\nAnswer:
\nThe average particle size decides the type of soil.<\/p>\n
Question 11.
\nWhich type of soil causes early waterlogging conditions?
\nAnswer:
\nClayey soil<\/p>\n
<\/p>\n
Question 12.
\nWhy is there a need to conserve the natural resources?
\nAnswer:
\nThe conservation of natural resources is essential for the sustainable development.<\/p>\n
Question 13.
\nWhat is biosphere?
\nAnswer:
\nThe life supporting zone, of the earth where the lithosphere, hydrosphere and atmosphere interact is called biosphere.<\/p>\n
Question 14.
\nWhat do you understand by top soil?
\nAnswer:
\nThe top soil is the uppermost layer of soil that contains humus and living organisms in addition to soil particles. It also holds the plants.<\/p>\n
Question 15.
\nName the three forms of nitrogen fixation.
\nAnswer:
\nThe three forms of nitrogen fixation are atmospheric fixation, biological fixation and industrial fixation.<\/p>\n
Short Answer Questions<\/span><\/p>\nQuestion 1.
\nWhat is atmosphere? State its importance to life on the earth.
\nAnswer:
\nA thick blanket of air present around the earth is called atmosphere. It is a bad conductor of heat as during day time, the atmospheric gases prevents excessive rise in surface temperature of the earth for the survival of life and at night time the same gases prevent the escape of heat from earth surface to keep it warm.<\/p>\n
The air present in atmosphere also contains life supporting gases such as oxygen and carbon dioxide.<\/p>\n
<\/p>\n
Question 2.
\nMention the different constituents of the soil.
\nAnswer:
\nThe different constituents of soil are<\/p>\n