Class 11 Environment Chapter 5 Environmental Pollution

Class 11 Environment Chapter 5 Environmental Pollution The answer to each chapter is provided in the list so that you can easily browse through different chapters Assam Board HS 1st Year Environmental Studies Chapter 5 Environmental Pollution Question Answer.

Class 11 Environment Chapter 5 Environmental Pollution

Join Telegram channel

Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board Class 11 Environment Chapter 5 Environmental Pollution Notes for All Subjects, You can practice these here.

31. What special position does the earth enjoy in the solut system?

Ans: The special position of the earth in the solar system is that it is the only planet that supports life. The cuvironment of the earth is conduct for the existence, growth and development of living beings.

32. What is solar system? How many planets are there in it? While is the planet that supports life?

Ans: The sun and its family of nine planets along with their satellites is the solar system. There are nine planets in it. The earth is the only planet that supports life.

33. How does environment affect life on earth?

Ans: Environment affects the size, shape and colour of plants animals and the ways in which they grow and live, Environment is responsible for survival of any particular organism. We get food, clothing and other things necessary for our survival from environment.

34. Mention some of the uses of water?

Ans: Water is essential for sustaining life. Water is also used for bathing washing cleaning, irrigating crop lands, generating electric powers, running factories and for many other service.

35. Write briefly about Hydrosphere?

Ans: Hydrosphere includes all water bodies on earth. The occans, seas, rivers, ponds etc, are all parts of it. Oceans and seas cover 7.1% of the hydrosphere. Only 0.04% is frets water usable by man and other i animals. Water is not as scarce as petroleum oil and coal because it is reusable.

36. Why is water not like coal or petroleum oil? Or, How is water different from coal and oil?

Ans: Coal and petroleum oil exhaust for ever once they are used. They cannot be savvied or recycled once they are burnt on the other hand water remains more or less at the same level due to water cycle prevailing on earth.

37. Write a short note on Lithosphere?

Ans: Lithosphere is the hard surface of the earth which accounts for 29% of the total surface area on the globe. It is the crust of the earth and it is made up of old rocks and minerals mixed up with various substances. It provides habitat to all kinds pf plants, animals and microorganism.

Lithosphere holds human civilization and all that man has made.

38. What are the divisions of our environment?

Ans: On the basis of its physical characteristics our environment is divided into:

(a) Lithosphere (land or soil)

(b) Hydrosphere (water bodies)

(c) Atmosphere (air)

(d) Biosphere (Plants and animals)

39. What is the importance of air?

Ans: Air is essential for all living beings in the biosphere. Man cannot live even for few seconds without air. He breathes 22000 times a day and inhales 16 Kg. of air from the atmosphere. Air is the store house of oxygen for man and other living beings and of carbon dioxide for trees and plants without air there will be no rain, cloud, and snow, fog etc.

40. How would you explain water cycle?

Ans: Water moves in the atmosphere in cyclic order. Water cycle begins with the evaporation of oceans, seas, rivers, lakes and all other water bodies. Evaporation occurs due to sun heat. The vapour forms cloud in the sky and then comes down to earth in the form of raindrops hail stones, dewdrops and snowfall etc.

41. What is atmosphere and why is it necessary?

Ans: The gaseous cover that surrounds the earth on all sides and controls life on it is called atmosphere. It protects earth’s surface from becoming too hot. It filters the solar radiations and prevents the harmful ultra violet rays from reaching the earth’s surface.

42. What are the main sources of air pollution?

Ans: Air pollution occurs when pollutants are released into air. Ulle main air pollutants are automobile exhaust, industrial smoke, solvent and radioactive radiation and particulates.

43. What is smog? What harm does it do?

Ans: The word smog has been formed of smoke and fog. Smog IS a thick layer of Smokey fog that floats over cities Smog has occurred over London, Glasgow, Delhi, Chennai, Kolkata. About 3.500 to 4000 people had died in the London smog of 1952. Smog causes respiratory trouble leading to slow but painful death.

44. Write a short note on solvents?

Ans: Solvents are used in paints, polish and sprays. The use of paint, polish etc have been increasing Accordingly the use of solvent too is increasing steadily. The spray materials remain suspended in air for a long time and are very harmful to man. Pesticides and insecticides contain solvent. They pollute air in rural areas.

45. What is particulates and what do they do?

Ans: Particulates are commonly Known as SPM (Suspended Particulate Matter). They consist of both solid and liquid tiny particles. They include dust, mist, spray, smoke, fumes etc. Normally chimneys in factories and power plants pour them out. Particulates create respiratory problem in human beings.

46. What is ozone layer? What is its function?

Ans: Ozone layer is a gaseous layer in the atmosphere. It exists about 30 to 60 km above the surface of the earth. It is like an umbrella that protects the living beings and plants from the dangerous and harmful Ultra Violet Rays.

47. Who detected the ozone a hole? What colored it?

Ans: A British Antarctic Survey Team reported 40% loss in ozone layer. They detected it in 1985. Scientists after study found that the new threat, the hole in the ozone layer was caused by a chemical called CFC (Chloro Fluoro Carbon), which is used in modem personal care products, and Refrigerators.

48. Write a note on Greenhouse and its usefulness.

Ans: Green house is made of glass. It is used for growing plants. During winter season in the cold countries the insulation is not sufficient for plant growth. The green house allows visible sunrays to enter into it, but prevent the infrared rays to go out. Thus gradual warming up takes place inside the green house favouring growth of the plants.

49. What green house effect?

Ans: The green house effect means a progressive warming up of the earth’s surface due to blanketing effect of man made carbon dioxide and some other gases in the atmosphere, with the increasing accumulation of carbon dioxide in the atmosphere global temperature will increase gradually. 

50. What will be the effect of global warming?

Ans: If temperature riser gradually as a result of global warming the glaciers will melt, the level of the water bodies like sea and ocean will rise and many low lying areas will be submerged. The marine ecosystem will be damaged affecting all aquatic life.

51. What is acid rain? What causes it?

Ans: When rain water contains acid, it is called acid rain. Pollutants like oxide of sulphur, nitrogen an carbon remain accumulated in the atmosphere. Rain water dissolve them and transforms them into weak acids and the drops finally come down to earth in the fortify of acid rain. Amount of acidity depends on the accumulation of the gases mentioned above.

52. What are the effects of acid rain?

Ans: Acid rains are the main cause of deaths of lakes for which it is called lake killers. Acid rain kills aquatic lives including plants and animals. It destroys the mineral elements and other nutrients of soil and adversely affects production. It also affects human beings and building etc. and other structures.

53. What are the major water pollutants?

Ans: When water becomes unfit for drinking or supporting life due to degradation of its quality it is called polluted. Industrial wastes, home sewage, run off from mining area or crop field, hot water from power plants, oil and radioactive wastes are the major water pollutants.

54. Show how oil pollutes water?

Ans: Oil tankers sailing in sea, sometimes develop leakage or sometimes they meet with accidents. As a result oil flows down to the surface of the sea water off. Shore drilling also releases some amount of oil into sea water. The oil spreading in sea water affects birds other aquatic life. Feathers of aquatic birds are socked in oil and they die soon.

55. How does power plants pollute water?

Ans: Fresh water flow is needed in power plants. Water-cools down the steam condensers. After cooling the condensers the hot water is released into water bodies, which changes the temperature of the water. This is called thermal pollution. Changes in temperature of water can harm fish populations.

56. Write a note an earth’s environment.

Ans: “Environment means surrounding. We remain surrounded by various types of radiations, air, water, soil rocks and minerals which form the abiotic factors of the environment. We live interacting with them similarly we remain surrounded by historic environment consisting of living organisms. We live reacting with them and we are inter related with them. Environment affects size, shape and colour of plants and animals. 

The environment may also be responsible for survival of S9me certain organisms. We get our food, clothing and shelter from our environment. Man also lives in a cultural environment. He lives surrounded by things he has made. Among the nine planets in the solar system only the earth has an environment that can life. It is earth’s environment that has made the existence, growth and development of living beings. Based on its physical characteristics of earth’s environment are divided into: Lithosphere, Hydrosphere, Atmosphere and Biosphere. Biosphere supports life and it is related to other three spheres.

57. Write a note an Hydrosphere.

Ans: Hydrosphere is the water bodies an earth, 71% of one planet is covered by the oceans and seas 96.5% of the total water on earth is found in the seas and oceans, 1.76% of the total water is there in the ice caps and glaciers. 1.70% is the ground water. Only the balance 0.04% is fresh water. Fresh water is found in the rivers, lakes and streams, Fresh water is not abundant. Still we do not feel scarcity of water. 

Because water is not exhaustible source like coal or petroleum oil. Water cycle on earth keeps the water level almost steady. Water cycle, begins with evaporation of sen and ocean water under the heat of sun. The vapour sails in the sky in the form of cloud and then comes down to earth as raindrops, dew, fog or snow. Water is an essential life-supporting element on earth. Besides drinking, water is used for bathing, cleaning, irrigating. and generating electric power and so on. Much ancient civilization flourished on riverbanks mainly because of the water streams.

58. Write a note on atmosphere.

Ans: The atmosphere is a gaseous cover surrounding the earth. It preserves life on earth. The atmosphere protects life on earth by way of filtering the sunrays. It prevents the harmful ultra violet rays of the sun from coming to earth’s surface. Air is essential for all types of life in the biosphere. Man cannot survive even for few seconds without air. A man breathes 22000 times a day inhaling 16 kg of air from atmosphere. Oxygen in the air is essential for man and animals while carbon dioxide is essential for trees and plants. Air is the reservoir of both oxygen and carbon die oxide and many other gases. Without air there will be no wind, clouds, fire and rain on earth. Air is a mechanical mixture of several gases. It contains 78.084% nitrogen, 20.95% oxygen, 0.93% argon and 0.03% carbon dioxide.

59. Write a note on environmental degradation.

Ans: Thousands of years ago the primitive men depended on nature for his food, drinks and shelter. They hunted in forests, fished in water and ate wild fruit and thus satisfied their simple needs. Population grow thore and society developed, man changed the natural habitat to villages,towns and cities, railways, highways, factories and industries were established with this change from started the process of environment pollution or degradation. 

Not only man natural forces also pollute environment. Earthquake, volcanic eruptions, land-slide, floods etc degrades environment. Nature has her own system of recovering minor environment degradation. When exploitation of Nature by man is unlimited nature fails to recover. The earth has been facing serious environmental problems during the previous three decades. Increase in population, spurt in technology aided by mans greed to get more and more things have polluted air, water and soil. The atmosphere is so much polluted now that t it has paused a threat to mankind and other living beings. Unless something

is done urgently environmental degradation may endanger all life on earth. 

60. Mention some of the measures to be adopted for controlling air pollution.

Ans: The following measures should be adopted for controlling air pollution:

(a) The engines of the automobiles should be redesigned the emissions at minimum level.

(b) Steps should be taken for 

(i) regular servicing of the vehicles.

(ii) use of filters.

(iii) replacement of old engines and parts by new one.

(iv) proper tuning-ups of the engines should be done.

(c) Industries should be located at a safe distance from the residential areas.

(d) TraditiOnal use of fire-wood, coal etc.should be minimized and smoke-free devices should be used. Forest fires also should be ‘Checked

(e) Without implementation of pollution control system, industries should not be accorded permission for production.

(f) There should be greenbelt around towns, townships and villages. Also there should be green belt around industries.

(g) Railways should use electric engines instead of coal or steam engines.

(h) There should be strict provision of law regarding pollution control in case of automobiles and industries.

61. What is water pollution? Suggest some of the measures for controlling water pollution.

Ans: When water becomes unfit for drinking or supporting life due to degradation of its quality. It is said to be pollution. The industrial wastes, home-sewage, run-off from mining area or crop fields, hot water from power plants, oil and radioactive wastes are the major water pollutants.

Following measures are to be adopted for controlling water pollution:

(a) There should be strict regulations by Government to the effect that no industry can release industrial wastes into rivers or streams without proper treatment in the effluent treatment plant. Production should not be permitted without the establishment of the treatment plat.

(b) Domestic and other sewage should be treated in sewage treatment plant, and only after such a treatment it should be allowed to be discharged into water bodies.

(c) Use of chemical pesticides and fertilizers should be limited and only herbal pesticides should be used.

(d) There should be complete ban an disposal of dead bodies of man and animals into rivers. River banks should be kept clean.

(e) Aquatic plants should be cleared at short intervals. shorti

(f) Water should be kept purified from harmful micro organisms by using potassium permanganate.

(g) Above all people should be made aware about the harmful effect of water pollution. So that they learn to protect themselves from water borne diseases.

62. Describe, how the Cosmic Rays pollute our environment?

Ans: One naturally occurring radiation is the cosmic radiation of cosmos mays. These rays come from extraterrestrial sources. These rays are composed of numerous high moving particles and high energy radiation with gamma rays. So when the cosmic rays fall on earth and induce radioactivity on some elements like carbon, tritium and beryllium. As the cosmic rays induce radioactivity, it may pollute our atmosphere.

63. “Now-a-days man has been artificially producing radiation of various types. Cite examples in support of the statement.

Ans: Man can tolerate the less ionizing radiations. But with the advent of time, man has been artificially producing gradations of various types out of necessity in different fields and use the harmful rays also. Scientists discovered x-rays and have used x-rays in diagnosis and research. Gamma rays are also used in treatment of diseases, in industries, in agriculture and food preservation. Similarly man has used ultraviolet and infrared radiation and also microwave,

64. Name four heavy elements.

(a) Uranium

(b) Thorium

(c) Radium

(d) Plutonium.

Ans: The four heavy elements are:

65. Describe the effects of radiation on environment? 

Ans: The effects of radiation on environment are very dangerous.

These may divided into two:

(a) Immediate effect: The immediate effect which reveals itself in burn injury, loss of hair, impairment of bone, bone marrow, leukaemia, cancer, foetal abnormality, foetal death, abnormal birth, and immediate death of the victim.

(b) Delayed effect: The delayed effect is usually detectable after years. One of such effects is gene mutation. This is of serious nature, for it affects the future generations.

66. What do you mean by radioactive substance? Name the radioactive radiations. 

Ans: Uranium, Radium Thorium and Polonium are heavy elements. These elements are used to produce nuclear energy and weapons. These elements namely Uranium, radium polonium and thorium are called the radioactive substance.

Radioactive radiations are of three types-Alpha, beta and gamma. 

67. State the nature of the radioactive radiations.

Ans: There are three types of radioactive radiations-alpha, beta and gamma. Alpha is positively charged parties, beta is negatively charged particles and gamma is not particles but electromagnetic waves of very short wave length.

68. How does a nuclear fission bomb and its radioactive fallouts affect the environment?

Ans: When the nuclear fission bomb is exploded, the radioactive materials start moving afloat in the sky and form dense dark clouds. These clouds then spread out within a few hours. But two or three weeks later they extend up to several hundred kilometres of the space in the sky and pollute the atmosphere. They not only pollute the air but gradually they pollute both the land and water. In this way the nuclear bomb and in radioactive fallouts affect the environment.

69. Explain how radioactive radiations may affect the future generation.

Ans: During the Second World War, USA dropped nuclear bombs on Hiroshima and Nagasaki of Japan. But after about more than 50 years, abnormal and deformed children are being born even now and this because of radioactive radiation. So we find that the radioactive radiation is very harmful to our future generation.

70. Most of the noises are man-made. Explain.

Ans: Any of our works creates some noise. Most of the originate crise primarily from industries, factories and transports. Modem civilization creates more and more noise. Noise inside many factories become hazard to health.

Heavy machines of industry or factory furnaces, powerlooms, generators, compressors, grinding mills etc. are the industrial sources of noise pollution

Transport like heavy diesel vehicles, trains, motorcars, three wheelers. two wheelers, aeroplanes, jet crafts etc. are the prime sources of noise pollution. That is why most of the noises are man-made.

71. Mention a few sources of sound are which have intensity harmful to human health.

Ans: A siren makes a noise of 150-160 decibels, an aeroplane makes 120-140 decibels, a jet aircraft makes 140 decibels, a factory makes 110 decibels, horn of vehicles make 95 decibels and heavy truck makes 90 decibels. If any of these sounds, lasts for more than four hours at a stretch,it can effect our whole body. It can also affect us mentally and physically.So such kinds of noise are very harmful to us and our environment.

72. What is noise? What do you mean by noise pollution? 

Ans: The unpleasant and unwanted sound is called noise. Too much noise pollutes the environment. It is also no less harmful than air or water pollution. At present a noise pollution has become serious problem to us.

73. Describe the sources that produce noise.

Ans: Every work we do creates noise. Industries, factories, electric looms, generators, stone crushers, trains, motor vehicles, three wheelers, two wheelers, aeroplanes, jet planes, construction of buildings and bridges, playing radio, TV, stereo etc. with high volume of sound creates noise.

74. Describe how noise pollution affects human organs. 

Ans: Noise above 80-120 decibels causes hearing impairment and total deafness. Excessive noise causes hypertension, heart trouble, giddiness, fatigue and insomnia. A sudden or prolonged noise may damage our eardrums.

75. Describe the measures that can be taken for controlling noise pollution.These are as follows:

Ans: There are several measures for the control of noise pollution.

(a) General awareness.

(b) Noise reduction at source

(c) Suggestions from expert bodies

(d) Traffic control

(e) Noise-free zone

(f) plantation

(g) Enforcement of law.

76. Discuss the laws and acts enforced by the government of India to control noise pollution.

Ans: The government of India have enforced many acts and laws to control noise pollution. These are Motor Vehicle Act of 1939, Aircraft Act of 1934, the Factory Act of 1948 and the Indian Penal Code, No. 268.

77. What are the main causes of deforestation?

Ans: Following are the main causes of deforestation:

(a) Fuel crisis.

(b) Opening of new farming land for food and cash crop.

(c) Demand for residential areas for growing population.

(d) Demand for timber and grazing land 

(e) Industrial and commercial demand.

78. Mention the factors responsible for the decrease of soil quality.

Ans: Decrease in the quality of soil is caused due to:

(a) Accelerated rate of soil erosion.

(b) Decrease in plant nutrients.

(c) Decrease in soil microorganisms.

(d) Excess or deficit of moisture content.

(e) High fluctuation of temperature.

79. How does sewage and other domestic waste pollute the land and ground water?

Ans: The sewage sludge contains appreciable concentration of toxic heavy metals. When used continuously for irrigation, metals like zinc.nickel, chromium, lead etc. accumulate in the soil and pollute the land and subsequently find their way to the ground water and pollute it too.

80. What are the causes of waterlogging? Can it be averted?

Ans: Unplanned construction of embankments, roads, railway lines, lack of proper drainage and sewage system, and excessive irrigation are the causes of waterlogging Yes, it can be averted by constructing the roads, railway lines, embankments in scientific method. The drains should also be constructed in scientific method.

81. Describe the role of microbes in sustaining the quality of solid and helping the plants grow.

Ans: Soil is made of dust, sand, clay and organic substances. Many minute organism are found in soil, these are microbes. Microbes enrich the soil and make it fertile.

Plants cannot absorb dissolved food in the soil unless it is broken into tiny parts by microbes. Without the microbes, the plants would have not survived. In this way the microbes helping the plants grow.

82. Why is Surat the cleanest city?

Ans: Surat was the dirtiest city in India which was infested with rodents and plague had been a great menace. But the Municipal Corporation now spends huge amount of money to clear the garbage. So it is now the cleanest city in India.

83. Enumerate and explain the factors responsible for degradation of land.

Ans: There are four factors responsible for degradation of land. These are:

(a) Action of wind and rainfall

(b) Waterlogging

(c) Chemical fertilisers and pesticides

(d) Garbage.

84. Discuss how strong winds and heavy rainfall degrade the land?

Ans: The green cover of earth’s surface protect the land from outer effects. Roots of plant bold the soil particles tightly and make it compact. But when the forest cover is removed the soil becomes less compact and strong wind can blow off apart of it.

The rain water also can easily wash away. Such soil and deposit in rivers, ponds or lakes. In this way the winds and heavy rainfall degrade the land.

85. What do you mean by deforestation? What are its effects?

Ans: Destruction or removal of forests by denudation is called deforestation.

For deforestation the drought and flood occur severely. Deforestation causes of soil erosion. Deforestation disturb the ecological system of our environment.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top