R

Guide to

Environmental Sciences A Comprehensive Book for UGC, UPSC, IFS, Banking and Other Recruitment and Entrance Examinations

Dr. Birendra Bahadur Singh

R. Gupta's®

Environmental Sciences

RAMESH PUBLISHING HOUSE, New Delhi

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Book Code: R-1101 ISBN: 978-81-7812-859-7 HSN Code: 49011010 Price: ` 190

CONTENTS 1. NATURE OF ENVIRONMENTAL STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. NATURAL RESOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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3. ECOSYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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4. BIODIVERSITY AND ITS CONSERVATION . . . . . . . . . . . . . . . . . . . . . . . . . 64 5. ENVIRONMENTAL POLLUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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6. SOCIAL ISSUES AND THE ENVIRONMENT . . . . . . . . . . . . . . . . . . . . . . . 120 7. HUMAN POPULATION AND THE ENVIRONMENT . . . . . . . . . . . . . . . . . 141 8. NATURAL DISASTER AND ITS MANAGEMENT . . . . . . . . . . . . . . . . . . . 162 9. CASE STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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IMPORTANT TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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MULTIPLE CHOICE QUESTIONS (MCQs) . . . . . . . . . . . . . . . . . . . . . . . . . . 184

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Guide to

Environmental Sciences

The earth system that has evolved towards its present state of high complexity in continuous interaction with man and biota that inhibit it. The present concern is to understand the relationship between environment and life, it can sustain on earth. The term ecology means the study of relationship between living things and their environment which is important to understand the development of the earth's atmosphere and evolution of life. The composition of the atmosphere has been greatly influenced by the processes involving living organisms and their activities.

INTRODUCTION The earth is 5 billion years old. It is the only celestial body where life exists and the only known habitable planet for man. Land, oceans and the atmosphere are connected with each other. The original atmosphere was devoid of oxygen and consisted mainly of hydrogen, ammonia, methane, carbon monoxide, hydrogen sulphide and a few other small molecules which were unable to sustain life as we know today. However, photochemical reaction have played an important role in the generation of oxygen. It was because oxygen that life on earth could be made possible. CO 2

ENVIRONMENTAL SCIENCES

O2

The word environment is derived from the French word ‘environ’, means surround or encircle. The environment consists of biotic and abiotic substances. So, we can define ‘‘Environmental Sciences is the application of all fields of natural science towards solving environmental problems’’ Zoology, Botany, Geochemistry, Biochemistry, Chemistry, Geology, Physics, Meteorology and many other branches/disciplines are included in the Environmental Sciences. Education and mass communication do help in understanding the socio-economic aspects of environment. Mathematics, Statistics and Computer Science also help in management of environment. The Environmental Sciences is, therefore, a multidisciplinary science, which may require attention of experts from different discipline/ branches of science when decisions regarding environment related matters have to be taken.

Atmosphere C,N,O

Plants

H2O

Atmosphere CO 2 N2 O2 Animals

Hydrosphere H2O S, P Minerals from soil lithosphere

Fig. 1. The material contributions for the three sub-divisions of ecosphere to maintain life.

Environmental studies/sciences courses are most rapidly growing courses in under-graduate 3

Environmental Sciences

4

and post-graduate level at many universities in the India. Individual branch/subjects are Sciences, developing Environmental Environmental Biology, Environmental Chemistry, Environmental Geology and many similar courses to address society's changing needs.

of mankind. The processes such as climatic system and the biogeochemical cycles are interconnected with the presence of water in the form of vapour, liquid and ice. Thus, the major biogeochemical cycles are vital to the life support system on the earth.

Biodiversity Biogeochemical Cycle Human beings need clear air, water, food shelter and easy mobility. As long as the human needs are small they are met out of the natural ecosystem, without disturbing the ecological balance because the ecosystem has a natural ability to regenerate itself by various nature.

Air, Air, Water, Water, Land Land & & Biodiversity Biodiversity

Biosphere Biosphere Photosynthesis Photosynthesis

Mutation   Mutation



Speculation   Speculation

*Carbon, Carbon,Phosphorus, Phosphorus Nitrogen, Oxygen, * Sulphur Nitrogen,Cycles Oxygen * Sulphur etc. Etc.  Water cycle Cycles  Soil formation  Water cycle  Soil formation

 

Competition Competition

 Parasitism  Parasitism  Co-adaption  Co-adaption  Survival 

Fig 2. Interactive components of the Biosphere The biogeochemical cycles involving movements of key chemical constituents through the earth system are essential for maintenance of life on earth. In addition to the sustenance of life, biogeochemical cycles play a major role in determining the atmospheric concentrations of active gases known as green house gases. The biogeochemical cycles also establish environmental conditions leading to the production of oil and minerals resources. The cycling of nutrients in the ocean plays a dominant role in oceans biological productivity. The earth's mineral resources are of great significance to the social and economic welfare

It is very essential in understanding the role of biodiversity in relation to structure and function of the ecosystem. In view of deforestation in tropical region, it is considerably very important in preserving the species and the natural ecosystem. The natural ecosystem helps to preserve air, soil and water and thus preserves the health of the environment by preventing degradation and loss of species. The existence of biodiversity of species helps in resisting any extreme disturbances caused to the ecosystems by natural calamites. It is also essential to deal biodiversity of plants, animals and microorganisms at the levels of terresterial fresh water and marine systems. A study of global and comparative biogeography may provide information regarding the role of functional properties if biotic and diversity to environmental changes and in addition, it will also help in conservation of genetic resources of wild species. The lack of marketing facilities, lack of technical and financial support, involvement of middlemen in the business and large range of variation in the selling price of medicinal plant that keeping away farmers from the main trade. Many pharmaceuticals have traditionally been derived from plants and animal sources. Extracting medicines from plants are worth over 60 billion dollars a year (Govt. of India 2006). The total percentage of the people in tropical areas depend upon traditional medicines. Penicillin and tetracycline and amongst the 3000 antibiotics extracted from mirco-organisms. Guggal is an oleogum which is used in ayurvedic medicines for its anti-inflammatory, anti-rheumatic and hypocholesteral activity.

Nature of Environmental Studies

Social Values Social value is one of the instrumental values where some thing which has a means to another's end. Materialistic uses of biodiversity are the core of instrumental value that biodiversity has distinct social value attached with different societies. Goods and services provided by ecosystems to our society include: 1. Provision of food, fuel and fiber.

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2. Provision of shutter and building materials. 3. Purification of air and water. 4. Detoxification and decomposition of wastes. 5. Generation and renewal if soil fertility, including nutrient cycling. 6. Control of pests and diseases. These are the social values of biodiversity because biological resources provide the basis for life on earth including men.

Human Impact Impact Human

Human Human wellbeing well being

Biological Biological diversity diversity

Biological Biological resources resources

Human Human Human well being well being wellbeing

Ecological system Ecological system

Fig 3. Interrelationships of Human Biodiversity

Environmental Degradation There is a dynamic equilibrium between various components of the environment and between geosphere and biosphere. The existence of dynamic equilibrium means that the organisms draws from the environment only the amount of essential materials that can be replaced at a role equal to its withdrawl. But human activities have resulted in detrimental changes in the earths air and water qualities and in the productivity potential of terresterial and aquatic ecosystems. Many interrelated impacts such as increasing desertification, deforestation increase in global temperature, geological processes including weathering of rocks, impact of mining, changed soil chemistry, due to agriculture practices, biotic events, effluents from factories and affecting the quality of life.

Earth land, aquatic system and atmosphere have provided humans with the goods and ecological sources, we need for our health and survival, food, medicine, clean air and water, healthy soil, pollination of crops. Control of pests, support for our diverse culture and gift of aesthetic beauty. But because of burgeoning population inappropriate use of our technologies many of these systems are threatened. Human activities are changing the environment at an unprecedented rate. The process of environmental degradation accelerated with the socio-economic activities, for example, agriculture, industrialization, transport and civil construction with increasing population the requirement of food grains and other consumer products increased greatly leading to further environmental degradation. The use of increasing amounts of fertilizer to

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Environmental Sciences

increase the productivity of land contributed to soil, water and air pollution. Industrial development has come to be regarded as a measure of progress for a country. However, the advent of industrialisation has brought in its wake many associated problems. These problems have led to the contamination of water courses and rivers passing through or nearby all cities which are grossly polluted due to sewage, solid wastes, leaches and industrial wastes. The discharge of all the industrial and domestic sewage in rivers are being done without bothering their deleterious effects on water quality. Industrial effluents released in the aquatic ecosystem, result in a wide variety of responses in fish leading to cytological and genetic damage. Which in turn can have far reaching effects on the very existence of many species. Although, potentiality of energy available from nuclear power is immense, radioactive wastelands manufacture of toxic chemicals can cause irrepairable damage to human and plant life in the form of mutation, malignancy etc.

Environmental Problems The problems which the human population is facing are mentioned as follows – 1. Water scarcity and deterioration of drinking water quality. 2. Depletion of agricultural and forest resources. 3. Green house effect and rise in sea level, impact on biosphere. 4. Extinction of living species 5. Increase in energy consumption and thus existing increasing pressure on the ecosystem. 6. Migration and urbanisation. 7. Deterioration, reduction of the quality of natural resources and loss of major portion of soil. 8. The impact caused by the depletion of the Earth's energy and mineral resources.

9. Production and use of fossil fuel based energy in the industrial countries and thus causing pollution in the form of acidification, global warming and climatic change. 10. The hazards of nuclear plants and disposal of nuclear waste. 11. Ozone layer depletion.

Environmental Protection In recent years mankinds consciousness has been aroused very strongly about the need for environmental protection and ecological preservation. It is of utmost importance that the people should be aware not only of the problems involved but also of the role to be played in protecting the environment. Along with the peoples participation at the grass root level, the formal education programme should be provided and implementing various environmental protection projects. In addition it is also very essential to develop environment friendly technologies and renewable energy sources following the principle of conservation. While developing technologies for the benefit of man, it is also essential to study simultaneously their impact on the environment so that cyclic processes, which the nature has devised for conservation of resources is not affected.

Aquaculture The wastewater suspended problems have plagued the man ever since he started living in communities and the different communities have managed the wastewater disposal problem in varying degrees of success. In nomadic society man functions as an integral part of the ecosystem where in his waste would be assimilated in the system without creating any disturbance to other components of the ecosystem. The urbanisation, however, resulted in generation of complex wastewater in large amount which imbalance the ecosystem resulting in present waste problem. The use of aquaculture technology can be of immense importance in this regard.

Nature of Environmental Studies Aquaculture is an important fast food farming sector. The current aquaculture production pattern provides a large gap between potential and actual yield. In order to make the composite operation of aquaculture more scientific it would be essential to approach with strong inputs of science and biotechnology. Apart from other resources that could be put to fish culture, the other resources that could be recycled into culture subsystems, are the organic materials in terms of domestic sewage, residues from agricultural products, animal residues, in form of urine and excreta and a host of agro based industrial nutrients out puts, but also possess and treat a large number of wastes which would no other farming system can assuming importance in the context of environmental management.

Public Awareness Environmental Awareness is considered essential weapon for environmental protection. It can be done in various ways. The lay man, people of tribal, rural, slums, women, students, teachers, planners, decision and policy makers and programme implementors all need to be oriented about the subject matter. The role of public in environmental protection, is not only to be aware of and be able to talk about the environment but also to assess and quantify the environmental implications. An environmental awareness should give some background of the environmental concerns. An environmental awareness should provide what may be called environmental literacy and prepare the public to think of the environment intrinsically in whatever activities they opt to undertake in future. The essential aim of awareness campaign is to evolves, produce and maintain goods, devices that modify the living environment for the comfort, happiness or welfare of human beings.

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India's Scenario In India the population is fast outstripping the country's carrying capacity. One in the seven persons on this planet lives in India with 16% of the World's population but only 2.4% of its land area, there is obviously a great demand on its natural resources. India is a country of physical, natural, climatic, cultural and linguistic diversity and is rich land with poor people whose population is close to 900 million with a land area of 329 million hectares. The pressure on land has been enormous as can be judged from the fact the total urban population in the year 1961 was 78 million which was now increased to 217 million, as result large scale deforestation has taken place. In this process India lost 0.19 million hectares of forest at the rate of 47,500 hectares per year. The deforestation problem led to development of wasteland and erosion of fertile soil. Shrinking and destruction of fresh water resources is feared to one of the serious major and impact of global warming. The burning of fossil fuels puts into atmosphere carbon dioxide which is causing gradual global warming. Tropical forest are big sinks for carbon dioxide and it is estimated that one kilometer of thick evergreen forest can use up all the carbon dioxide in one square kilometer column of atmosphere. The green house effect will shift agricultural production areas, raise the sea level to flood coastal cities, and disrupt natural economics. The industrial gases threaten to deplete the planets protective zone, shield to such an extent that the number of problems would rise sharply. Industries and agriculture put toxic substances into human food chain and into underground tables beyond reach of cleansing. India, a land of holy rivers, is fast becoming a land of highly polluted and even toxic rivers. The environmental problems that India is facing can be divided into three categories. Category-a includes problems arising out of lack of development, unhygienic slums, soil erosion,

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Environmental Sciences

lack of sanitation and protected water supply. Category-b includes problems caused by lack of environmental safeguards, waste disposal, water logging in irrigation project, pesticides pollution, fertilizers run-off into streams. Category-c includes problems such as global warming, ozone depletion, marine pollution, loss of genetic diversity and vehicular pollution. The challenge before the country is to preserve its environment, keep intact the capacity of already over-burdened land to feed its growing population and meet the basic energy needs. The immensity of environmental problems in India faces calls for innovative approaches. The problems range from pollution of 80 per cent of all available water, desertification and the soil erosion, the threat of water logging and salinity to one quarter of all irrigated land, acute shortage of land for growing fodder for 426 million livestock to prevent them from accelerating soil erosion to continuous loss of forest cover.

Stockholm Conference There is a growing awareness all over the world to protect the Earth's environment. The United Nations Conference on Human Environment in Stockholm (1972) put the environmental issues on the International agenda. It was estimated that about 70 per cent of world's income was going to top 25 per cent of the population. In other words, the sustainable life styles are associated with the wealthy that enjoy and consume over 80 per cent of World's energy resources while the poorest one billion people have to depend for life and security on common property resources.

Montreal Protocol The Montreal protocol (1987) was amended under pressure from India and other developing countries in London in 1990. The biggest Chlorofluorocarbon (CFC) consumers were reluctant to sign the amended protocol to phase out CFC voluntarily. In United States, the

average consumption of energy is highest in the world. In this country about 5 tonnes per capita of carbon is emitted annually into the atmosphere. On the contrary, India emits 0.4 tonnes of carbon per capita annually. Thus the a v e r a g e A m e rica n p ollu t e s the a tm osp h-e re 1 2 times more than average Indian. Twenty-five per cent of the world's population contributes 75 per cent of global environmental problem.

Rio Conference The first global gathering of heads of 165 countries participated in Rio's Conference. The United Nations Conference on the Environment and Development which organised Earth's Summit has estimated that about $625 billion will be needed a year over the next 5-10 years to help world-wide switchover to environment friendly technologies and address the immediate environmental problems.

Health and Environment Environment affects human health in two ways. The first way is concerned with direct effect of pollutants discharged by industries into air and water as well as by the emission of gases by automobiles. In urban population the occurrence of diseases are closely linked to the deterioration of air and water quality. The second way is concerned with the quality of environment at the place of work. Over the years it has been re cog nise d t ha t w or ke r s i n ce rta in occupations, such as textile mills or stone crushers suffer from occupational diseases. The deterioration of environment such as stagnant pools in villages and cities provides fertile ground for breeding of vectors. Many such diseases carrying vectors have developed immunity to pesticides, overcrowding and unhygienic living condition in cities specially in slums have also contributed to spread of other communicable diseases.

Vehicular Pollution One-fifth of vehicular population in India is concentrated in the major metropolitan cities.

Nature of Environmental Studies Nearly 70 per cent of vehicles are two and three wheelers which are mostly two stroke engine driven. Petrol driven four stroke engines constitutes only 14 per cent and diesel driven 8 per cent of total. Two-wheeler vehicle has been growing at rate of 20 per cent per year which will increase to 36 million in 2000 against 7 million in 1987. The consumption of gasoline and diesel by automobiles has increased from 1.5 and 7.2 million tonnes in 1980-81 to 3.5 and 14.8 million tonnes (per cent of world fuel consumption). The principal pollutants emitted by vehicles are carbon monoxide, hydrocarbons, Nitrogen oxide and particulate matter. Vehicle using petro-cum-based fuels also emit polynuclear hydrocarbons and traces of aldehydes. In addition, a varying amount of Sulphur dioxide is also emitted depending upon the sulphur content in the fuel.

Pesticide Pollution India is predominantly an agricultural country. In India almost 50% of the potential of food grains production is lost annually due to insect/ pests, pathogen etc. Pesticide plays an important role for control of pests in agriculture and public health programmes. India at present is the largest manufacturer as well as consumer of pesticide chemical in Southern Asia. Pesticide possesses potential health hazard not only to livestock and human beings but also to aquatic flora and fauna. The biomagnification and bioaccumulation of the pesticide in food chain of fishes of serious concern. The pesticides are most widely used to protect the standing crops from pest and to increase the yields of crops. However, they cause major harm to aquatic fauna via agricultural run-off and this has resulted in major ecological problems. The use of pesticides was new era in the application of man made chemicals in control of pest in which increased the production of

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food and helped in the eradication of diseases, but this great achievement has resulted in injury and death of variety of forms of life. Used in insect control these pesticides have contaminated the ecosystem and entered food chain causing damaging effects on the ecosystem and non-target species. The potential toxic compounds get distributed by variety of means and build up concentration in the soil and water and finally reach man. In this pathway they leave degrees of injuries to the life process. The aquatic organisms like fish are able to accumulate several fold higher concentration than the surrounding water with the contaminated pesticides residues. Fish can store up such pesticides in their visceral fat and edible muscle. Although the quantities of pesticides may be relatively small but the concentrations are still sufficient to have a deleterious impact on the fresh water ecosystems. A multiple of environmental problem has been associated with modern methods of agriculture. Most of these stem from abuse of pesticides and the use of persistent plant protection chemicals which have been banned in developed nations. Uses of synthetic fertilizers have led to nitrate pollution of water resources. The release of methane from paddy fields is another form of agricultural pollution, and even the pesticides residues in food chain (vegetables, eggs, fish, meat, milk products, edible oil and breast milk) have been detected.

Depletion of Ozone Layer Ozone layer depletion poses many serious threats in human health. As the stratospheric ozone layer thins, relatively more of the harmful wavelength of ultraviolet radiation will reach the Earth's surface. Ultraviolet radiation has many effects on animals, people, plants and materials. The radiation may result in widespread eye damage and outbreak of infectious diseases as well as an increase in the incidence of skin cancers. Vaccination against some diseases become less effective and more

10

Environmental Sciences

shorter wave ultraviolet radiation will trigger chemical reaction in the lower atmosphere, increasing smog and acid rains, leading to a rise in respiratory problems and increase in global warming and air pollution. Ozone layer depletion disrupts ocean life and affects the marine food web. It has been estimated that a 16 per cent ozone depletion would cause a 5 per cent decrease in plankton number, 7 per cent drop in fish yield thus representing a loss of 6 million tonnes of fish each year.

Waste Management The pollution problem of solid waste disposal is not different. Landfills and garbage overflow in most cities create another set of problem. There is also the problem of disposal of hospital waste. India generates around 25 million tonnes of municipal solid waste per year. Municipal waste has a very high proportion of biomass. Because of high amount of biomass present in the garbage, pellets obtained from garbage have heating value of 4000 k cal/kg and bulk density of 500 kg/cubic meter. It is estimated that about 100 kg of moist garbage yields around 30 kg of fuel pellets. The fuel pellets burn without smoke. The ash residue is only 5 per cent of pellet weight and is a good potassium fertilizer. Earthworms have been used to treat the waste. They provide ideal temperature, pH and oxygen concentration for speedy growth of useful aerobic and actinomycetes. The worm also produces enzymes which break complex biomolecules present in the garbage into simple compounds which are utilized by the microorganisms. The oxygen provided to the microorganisms accelerates various bioprocesses speeding up the decomposition of organic wastes. The oxygen rich micro environment eliminates anaerobic micro-organisms preventing the formation of foul smelling, obnoxious compounds like hydrogen sulphides and mercaptons.

Economic Development It is impossible to separate economic development issues from environmental issues. Many forms of development erode the environmental resources upon which they must be based and environmental degradation can undermine economic development. Poverty is a major cause and effect of global environmental problems. It is thus futile to attempt to deal with environmental problems without a broader perspective that encompasses the factors underlying world poverty and international equality. A main spring of economic growth is new technology. New technology offers potential for slowing the dangerously rapid consumption of finite resources. It also entails high risks including new forms of pollution that would change evolutionary pathways. Such related changes have locked the global economy and global ecology together in new ways. In past, we have been concerned about the impacts of economic growth upon the environment. Presently, we are forced to concern ourselves with the impacts of ecological stress. Ecology and economics are becoming more interwoven into a seamless net of cause and effect, locally, regionally, nationally and globally.

Sustainable Development The concept of sustainable development provides a framework for the integration of environmental policies and development strategies. Sustainable development seeks to meet the needs and aspirations of the present without compromising the ability to meet those in the future. In other words, sustainable development is a process of change in which the exploitation of resources, the direction of investments, the orientation of technological development and institutional change are all in harmony and enhance both current and future potential to meet human needs and aspirations. Sustainable development does imply limits imposed by the present state of technology and

Nature of Environmental Studies social organization on environment resources. Humanity has ability to make development sustainable.

Water Pollution Water is regarded as ‘polluted ‘when its quality or composition is changed directly or indirectly as a result of human activities, so that, it becomes less suitable for drinking domestic, agricultural, recreational, fisheries or other purposes. In India, rapid industrialization and urbanization have taken place during the last four decades. With this the higher risk of deterioration of environmental quality through discharge of wastes by industries and sewage by growing population has challenged the productive capacity of aquatic ecosystems. The latter comprise several interacting physicochemical parameter with organic and inorganic compounds, in dissolved or suspended state, and a variety of flora and fauna. Normally the chemical and biological factors of an ecosystem exist in the dynamic equilibrium in a fixed space and time. The waterbodies because of harbouring primary producers (aerobic autotrophs) have been endowed with a remarkable capacity to rejuvenate their vitality. But the disposal of sewage and/or industrial effluents into them affects their capacity of repurification and influences the biological system either directly or indirectly. Most of the industrial units discharge their effluents in nearby waterbodies, which adversely affect their normal life. The effluents usually contain high amount of inorganic salts, acids or alkalies, organic matter, suspended solids, toxic chemicals and heated water. The gravity of water pollution problem warrants a systematic research with a view to devise suitable methods for its detection, assessment and control. Since water pollution is biological approach and most of the microphytes grow in a wide variety of polluted and non-polluted habitats, one may hope that

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a knowledge about their pollution biology would provide an useful solution to this problem. The changes in water quality brought about by waste disposal in aquatic system can be assessed by observing changes in its physicochemical characteristics and the latter's effect on the distributional pattern and growth behaviour of aquatic organisms. It has been established that the changes thus brought about exert a selective action on the flora and fauna and the effect produced in them can be profitably used to establish biological indices of water quality. Studies on the deleterious effect of industrial wastes on physico-chemical properties of water and aquatic organism have incited considerable interest during the past two decades and researches in this discipline have considerably advanced.

Water Degradation in India Besides land degradation another key environmental problem is the ground water and surface water pollution. In a number of sites the ground water is severely contaminated with toxic metal such as manganese and chromium. In the concentration far so exceeding the limits prescribes for safe portable water by WHO. About 70% of the available surface water resources are severely polluted. Another consequence of such pollution spreading of water borne diseases which accounts for 2/3 of illness in India affecting productivity of the water. The per capita annual water availability was 5236 m3 in India which declined to 2464 m3 and this is expected to decline further in near future. Water quality is closely linked to type of water use and level of economic development. Rapid industrialization in developing countries and intensive agriculture have added a further dimension to water pollution in the form of chemical contamination. Urban populations are now exposed to hazardous chemicals as well as infectious agents in surface

About the Book The book ‘Guide to Environmental Sciences’, has been specially developed keeping in mind the requirements of students, examaspirants and other readers with academic as well as competitions’ point of view. The book is especially useful for the aspirants of various competitive exams such as UGC, UPSC, IFS, Banking etc. where this subject forms an essential part of the selection criterion. The main aim of the book is to present this specialised subject in a reader-friendly manner to make the readers study and practice numerous questions on its various topics thoroughly which are solved by the learned expert. The book comprises a wide spectrum of question-answers in MCQ form, covering all important topics and frequently asked in various exams. The book will act as an efficient tool to test your knowledge of the subject and preparation of exam. The book will definitely prove to be a boon to the inquisitive students, exam-aspirants, and other readers in improving and enhancing their knowledge of the subject and will immensely help them perform better in their respective exams and competitions. The book is highly recommended for study and self-practice of objective questions on the subject and to sharpen your problem-solving skills to a great-extent.

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