Geography MCQs PDF

 Your Achievement Our Commitment BEFORE ANYTHING ELSE, PREPARATION IS THE KEY TO SUCCESS. Civil Services Examinations are the most prestigious and coveted examinations in India. Due to the power, authority, reputation, this career attracts every asp...

 Your Achievement Our Commitment BEFORE ANYTHING ELSE, PREPARATION IS THE KEY TO SUCCESS. Civil Services Examinations are the most prestigious and coveted examinations in India. Due to the power, authority, reputation, this career attracts every aspirant to hold the post and become IAS/IPS officer. Union Public Service Commission (UPSC) and State Public Service Commission (SPSC) conduct this examination every year and lakhs of aspirants across the country toil for years together to crack this distinguished exam in the country. Being the toughest exam, it automatically consists of a vast and a detailed syllabus. Aspirants often find it difficult to cover the entire syllabus and lack a right direction for a proper and a systematic study for the exam. The most important aspect of this preparation journey are the NCERT books. Every year approximately 35-40 questions directly come from NCERT books. NCERT books also play a key role in understanding the Basic Concepts; so that aspirants can easily form the basic foundation of the entire syllabus. But due to the demand for many NCERT books which are required for study, it becomes exhausting to cover each and every NCERT book. NCERT MCQs series presented by Arihant Publications covers MCQS from Class 6th to 12th NCERT books ( both Old & New) in a comprehensive manner. The series is extremely useful for UPSC and State PSC examinations. The chapter-wise questions given in the sequential form in the series along with the source of the questions and detailed solutions will make the preparation easy and convenient. The factual accuracy and explanations make this series an authentic source for cracking the examinations. The book is adorned with questions prepared by a team of experts along with a vital role played by the Project Management team with members: Mona Yadav (Project Manager), Divya Gusain (Project Coordinator), Shivani Dixit, Ayush Rajput (Proof readers), Vinay Sharma, Kamal Kishor, Sonu Kumar (DTP coordinators), Shanu and Mazher (Cover and Inner designer). We hope this book will help the aspirants to achieve their goals of clearing UPSC as well as State PCS exams. Your valuable suggestions have always inspired us to strive for useful, authentic and more trustworthy publications. So your inputs and suggestions are welcomed for subsequent editions. We wish you all the very best for your preparation and journey!! Publisher  CONTENTS WORLD GEOGRAPHY Chapter 1. Geography as a Discipline 1-2 Chapter 2. The Universe 3-7 Ÿ Study of Universe Ÿ Solar System Ÿ Planets Chapter 3. The Earth 8-19 Ÿ Origin of Earth Ÿ Geological Time Scale Ÿ Motions of the Earth Ÿ The Moon Ÿ Latitudes, Longitudes and Time Chapter 4. Geomorphology 20-41 Ÿ Earth’s Internal Structure Ÿ Earth Movements Ÿ Theories of Distribution of Continents and Oceans on Earth Ÿ Rocks Ÿ Landforms Chapter 5. Climatology 42-62 Ÿ Insolation and Temperature Ÿ Atmospheric Composition and Structure Ÿ Structure of Atmosphere Ÿ Atmospheric Pressure, Pressure Belts and Wind Systems Ÿ Airmass Ÿ Cyclones Ÿ Moisture in the Atmosphere Ÿ Clouds and Precipitation Ÿ World Climatic Classification Chapter 6. Oceanography 63-75 Ÿ Distribution of Water on the Earth Ÿ Temperature and Salinity of Oceans Ÿ Oceanic Movements: Waves, Tides, Current Ÿ Oceanic Deposits Chapter 7. Biogeography 76-87 Ÿ Soils Ÿ Major Biomes Chapter 8. Agriculture 88-99 Ÿ Animal Husbandry Chapter 9. Mineral and Energy Resources 100-106 Ÿ Mineral Resources Ÿ Energy Resources Chapter 10. Industries 107-114 Ÿ Manufacturing Sector Ÿ Service Sector Ÿ Industrial Regions Chapter 11. Transport and Communication 115-121 Ÿ Transport Ÿ Railways Ÿ Airways Ÿ Waterways Ÿ Pipelines Ÿ Communication Chapter 12. World Population and Human Development 122-128 Ÿ Population Distribution and Growth Ÿ Population Composition Ÿ Human Development Chapter 13. Human Settlements and Tribes 129-133 Ÿ Human Settlements Ÿ Major Tribes Chapter 14. Continents 134-159 Ÿ Asia Ÿ Africa Ÿ South America Ÿ Australia Ÿ Antarctica Ÿ North America Ÿ Europe Chapter 15. Maps 160 INDIAN GEOGRAPHY Chapter 16. Location and Structure of India 161-164 Chapter 17. Physiographic Divisions of India 165-177 Ÿ Evolution of India’s Geological Structure Ÿ Himalayan Mountains Ÿ Northern Plains Ÿ Peninsular Plateau Ÿ Great Indian Desert Ÿ Coastal Plains Ÿ Islands Chapter 18. Drainage of India 178-187 Ÿ Indian Drainage Ÿ Himalayan Drainage System Ÿ The Indus Ÿ The Ganga Ÿ The Brahmaputra Ÿ Peninsular Drainage Ÿ Lakes Chapter 19. Climate of India 188-195 Ÿ General Features of Indian Climate Ÿ Indian Monsoon Ÿ Seasons in India Ÿ Rainfall Ÿ Climatic Classification Ÿ El-Nino and Southern Oscillations Chapter 20. Soils and Natural Vegetation 196-203 Ÿ Soils Ÿ Natural Vegetation Ÿ Forest Conservation in India Chapter 21. Natural Resources of India 204-209 Ÿ Water conservation Chapter 22. Agriculture 210-218 Ÿ Agriculture and Its Types Ÿ Cropping Seasons Ÿ Major Crops Ÿ Irrigation Chapter 23. Mineral and Energy Resources in India 219-227 Ÿ Minerals Ÿ Ferrous Minerals Ÿ Non-Ferrous Minerals Ÿ Conventional Resources Ÿ Non-Conventional Resources Chapter 24. Industries 228-236 Ÿ Types of Industries Ÿ Industrial Regions of India Chapter 25. Transport and Communication 237-243 Ÿ Railways Ÿ Inland Waterways Ÿ Air Transport Ÿ Pipelines Ÿ Ports Ÿ Communication Chapter 26. Human Settlements 244-245 ENVIRONMENT AND ECOLOGY Chapter 27. Environment 246-247 Chapter 28. Ecology and Ecosystem 248-254 Chapter 29. Biodiversity 255-259 Chapter 30. Biosphere Reserves, National Parks and Wildlife Sanctuaries 260-264 Chapter 31. Greenhouse Effect, Ozone Depletion and Climate Change 265-267 Ÿ Greenhouse Effect Ÿ Ozone Depletion Ÿ Climate Change Chapter 32. Environmental Issues 268-274 Ÿ Pollution Ÿ Water Pollution Ÿ Sound/ Noise Pollution Ÿ Solid Waste Ÿ Land Degradation and Desertification Chapter 33. Sustainable Development 275-276 Chapter 34. Disaster Management 277-281 Ÿ Earthquake and Tsunami Ÿ Landslides Ÿ Tropical Cyclones Ÿ Floods and Droughts Ÿ Disaster Mitigation Practice Sets 1-3 285-296  World Geography 01 Geography as a Discipline New NCERT Class XI (Geography as a Discipline), Old NCERT Class XI (Geography as a Discipline), New NCERT Class XII (Human Geography : Nature and Scope) 1. Which of the following statements with reference Exp. Both the statements (1) and (2) are correct with to the evolution of geography as a subject are reference to the evolution of geography. incorrect? (Chap 1, Class-XI, New NCERT) As there are many scholars from India, Arab and Greece who tried to understand the universe around us but (a) The term Geography was first coined by a Greek among them the foundation of Geography as a science scholar Eratosthenes. was mainly laid by Greek scholars. (b) The subject matter of discipline has been taken from The word ‘Geography’ has been derived from two roots Natural sciences. from Greek language Geo (earth) and Graphos (c) Geography can be considered as the study of Areal (description). Differentiation over Earth. In systematic approach, a phenomenon is studied all (d) Geography cannot be used to describe phenomenon over the world as a whole, and then the identification of on the Earth with a cause and effect relationship. typologies or spatial patterns is done. This approach was j Ans. (d) introduced by Alexander Von Humboldt, a German Exp. Statement (d) is incorrect with reference to the geographer (1769-1859) and Karl Ritter. evolution of geography as a subject because geography can be used to describe phenomenon on the Earth with 3. Consider the following statements with reference a cause and effect relationship. to Possibilism and Determinism. (Chap 1, Class-XI, Old NCERT) Geographers do not only study the variations in the phenomena over the Earth’s surface (space) but also 1. Possibilism views humans as capable of modifying study the associations with the other factors which the environment and using natural resources cause these variations. according to their own needs. 2. Determinism propounds that human choices and 2. Consider the following statements with reference needs are restricted by natural factors. to the evolution of geography. 3. F Ratzel belonged to the Deterministic School. (Chap 1, Class-XI, Old NCERT) Which of the statement(s) given above is/are 1. The foundation of Geography as a science was correct? mainly laid by Greek scholars. (a) 1 and 2 (b) 2 and 3 2. German geographers such as AV Humboldt and (c) 1 and 3 (d) All of these Karl Ritter began the systematic study of geographical phenomenon in the early 19th j Ans. (d) century. Exp. All the statements are correct with reference to Which of the statements given above is/are Possibilism and Determinism because the Possibilism correct? school of thought offers many choices to human. In this approach, emphasis is on human rather than nature and (a) Only 1 (b) Only 2 human is seen choosing his needs according to his own (c) Both 1 and 2 (d) Neither 1 nor 2 culture and is also “the judge of their use”. j Ans. (c)  NCERT MCQs Geography as a Discipline 02 The French School of Geographers is firm supporter of The shape of the Earth is Geoid but the basic tool of a possibilism. According to Determinism thought, geographer is a map which is two-dimensional human is a slave of nature. There is direct dependence representation of the Earth. of human beings on nature for resources and nature is taken as a powerful force, it is worshipped, revered and 6. Match the following lists correctly and choose the conserved. correct code. (Chap 1, Class-XI, Old NCERT) Kant, Humboldt, Ritter and German expert Ratzel and List I List II his student Ellen Churchill Semple belong to the (Geographer) (Field of Work) Deterministic School. A. H Mackinder 1. Quantitative Methods 4. Which of the following pairs is/are matched B. W Christaller 2. Regional Geography correctly?(Chap 1, Class-XII, New NCERT) (UPPSC Pre 1994) 1. Neo Determinism – Griffith Taylor C. Peter Haggett 3. Settlement Hierarchy 2. Determinism – E Huntington D. W Davis 4. Cycle of Erosion 3. Possibilism – Vidal De La Blache Codes Codes (a) 1 and 2 (b) 2 and 3 A B C D A B C D (c) Only 2 (d) All of these (a) 1 2 3 4 (b) 2 3 1 4 (c) 3 1 4 2 (d) 4 2 1 3 j Ans. (d) Exp. All the pairs are correctly matched as Griffith j Ans. (b) Taylor gave the concept of Neo Determinism also Exp. The correct matching is A-2, B-3, C-1, D-4. known as ‘Stop and Go Determinism’. H Mackinder He gave his greatest contribution on Determinism can be defined as naturalisation of Heartland Theory in the field of regional geography. humans. E Huntington was one of the pioneers of this W Christaller He gave his greatest contribution approach. on Central Place Theory in the field of settlement Vidal De La Blache was a pioneer of possibilism along hierarchy. with Lucian Febre. Possibilism means humanisation Peter Haggett He was well-known for his work on of nature. quantitative methods as quantitative revolutionaries. W Davis He gave the theory of cycle of erosion where he 5. Which of the following statements is/are correct defined the three distinct stages of river erosion. regarding geography? (Chap 1, Class-XI New NCERT) 1. Biogeography is closely related to botany, 7. “Human geography is concerned with the study of zoology as well as ecology as human beings are changing relationship between unresting man and located in different locational niche. unstable Earth.” Who gave this statement about 2. Geography is very much linked with the study of human geography? (Chap 1, Class-XII, New NCERT) astronomical locations and deals with latitudes (a) Paul Vidal De La Blache (b) Ellen Semple and longitudes. (c) Ratzel (d) W Davis Codes j Ans. (b) (a) Only 1 Exp. The statement about human geography was given (b) Only 2 by Ellen Semple. (c) Both 1 and 2 According to Ellen Semple “Human geography is the (d) Neither 1 nor 2 study of the changing relationships between the j Ans. (c) unresting man and unstable Earth” Exp. Both the statements (1) and (2) are correct In general terms Human geography is defined as “the regarding geography. Biogeography is closely related relationship between the physical/ natural and the to botany, zoology as well as ecology as human beings human worlds, the spatial distribution of human are located in different locational niche. Geography is phenomenon and how they come about, the social and very much linked with the study of astronomical economic difference between different parts of the locations and deals with latitudes and longitudes. world”.  02 The Universe New NCERT Class VI (The Earth in the Solar System), Old NCERT Class VI (The Earth in our Solar System), New NCERT Class XI (Origin and Evolution of Earth) Study of Universe 3. Which of the following statement is/are not correct about the state of early universe? 1. The state of universe before the occurrence of (Chap 2, Class-XI, New NCERT) the ‘Big Bang’ can correctly described by which (a) The distribution of matter and energy was not even. of the following terms? (Chap 2, Class-XI, New NCERT) (b) Differences in the density led to differences in (a) Nebula (b) Singularity gravitational forces. (c) Point (d) Atom (c) Galaxies started forming by the accumulation of a j Ans. (b) large cloud of hydrogen gas. (d) None of the above Exp. The term ‘Singularity’ correctly describes the state of universe before the occurrence of the ‘Big Bang’. j Ans. (d) According to the ‘Big Bang’ theory (expanding universe Exp. All the given statements are correct about the hypothesis) in the beginning, all matter forming the state of early universe. The distribution of matter and universe existed in one place in the form of a ‘tiny ball’ energy was not even in the early universe. This initial (singular atom) with an unimaginably small volume, density differences gave rise to differences in infinite temperature and infinite density. This existence gravitational forces and it caused the matter to get was termed as singularity. At the Big Bang, the ‘tiny drawn together. ball’ exploded violently, this led to a huge expansion of Hence, galaxies started forming by the accumulation of the universe. a large cloud of hydrogen gas. A galaxy contains a large number of stars. Galaxies 2. Which the following statements with respect to spread over vast distances are measured in thousands of ‘Expanding Universe Hypothesis’ is/are correct? light years. The diameters of individual galaxies range (Chap 4, Class-XI, New NCERT) from 80,000-1,50,000 light years. (a) The Expanding Universe Hypothesis was proposed by scientist Edwin Hubble in 1920. 4. Which of the following statements about the state (b) Edwin Hubble provided the evidence that the of universe are correct? (Chap 2, Class-XI, New NCERT) universe is expanding. 1. The universe is in an expanding state. (c) Both ‘a’ and ‘ b’ 2. The space between galaxies is increasing. (d) Neither ‘a’ nor ‘ b’ 3. The distance between the galaxies is found to be j Ans. (c) increasing and thereby, the universe is considered to Exp. Both the statements (a) and (b) are correct be expanding. regarding the ‘Expanding Universe Hypothesis’, 4. The formation of universe started almost 13 billion because the most popular argument about the origin of years ago. the universe was proposed by Edwin Hubble in 1920. In Codes this argument, he provided evidence that the universe is (a) 1 and 2 (b) 2 and 3 expanding and galaxies are moving a part with the (c) 1, 3 and 4 (d) 1, 2, 3 and 4 passage of time.  NCERT MCQs The Universe 04 j Ans. (d) j Ans. (a) Exp. All the given statements are correct about the Exp. Statement (a) is correct with reference to our Solar state of universe. System. The average density of the Earth is highest According to scientist Edwin Hubble, the universe is among all the other eight planets of our Solar System. It in expanding state and with passing of time, the space is about 5.514 g/cm 3. between the galaxies is increasing. The Big Bang Statement (b), (c) and (d) are incorrect. The largest Theory is the most widely accepted theory about the constituent element of the Earth is Iron (32.07%), Oxygen genesis of the universe. (30.12%) is the second and Silicon (15.12%) is the third According to which, the formation of universe started largest element in the composition of the Earth. almost 13.7 billion years before the present and it is The Sun contains 99.8% of the mass of Solar System and still expanding. the diameter of the Sun is roughly 109 times the diameter of the Earth. 5. Which of the following statements are correct about the formation of universe? 7. Given below is a list of stages of formation of (Chap 2, Class-XI, New NCERT) planets in the universe. Arrange the list in correct 1. Before the Big Bang, the universe was sequence using the codes given below. concentrated in a singular atom. (Chap 2, Class-XI, New NCERT) 2. The singular atom exploded violently which led 1. Condensation of gas cloud around the core to its rapid expansion. 2. Development of planetesimals 3. The present rate of expansion of universe is 3. Formation of planets more than its initial expansion. 4. Formation of localised gas lumps Codes 5. Formation of core of gas cloud (a) 1 and 3 (b) 1 and 2 Codes (c) 2 and 3 (d) All of these (a) 1, 2, 4, 5, 3 (b) 4, 5, 1, 2, 3 (c) 2, 1, 4, 5, 3 (d) 4, 2, 1, 5, 3 j Ans. (b) Exp. Statements (1) and (2) are correct about the j Ans. (b) formation of universe as in the beginning, all matter Exp. The correct sequence of the stages of the formation forming the universe existed in one place in the form of planets in the universe is 4, 5, 1, 2, 3. of a ‘tiny ball’ (singular atom) with an unimaginably Formation of localised gas lumps The stars are localised small volume, infinite temperature and infinite lumps of gas within a nebula. The gravitational force density. within the lumps leads to the formation of a core of the gas At the Big Bang, the ‘tiny ball’ exploded violently. cloud. This led to a huge expansion. Formation of core of gas cloud A huge rotating disc of gas It is now generally accepted that the event of big bang and dust develops around the core. took place 13.7 billion years before the present. The Condensation of gas cloud around the core In the next expansion continues even to the present day. stage, the gas cloud starts getting condensed and the matter Statement (3) is incorrect as there was particularly around the core develops into small rounded objects. rapid expansion within fractions of a second after the Development of Planetesimals The small rounded objects bang. But thereafter, the expansion has slowed down. by the process of cohesion develop into what is called Hence the present rate of expansion of universe is not planetesimals. Larger bodies start forming by the collision more than its initial expansion. and gravitational attraction causes the material to stick together. 6. Which one of the following statements is Formation of Planet In the final stage, planetesimals which correct with reference to our Solar System? are a large number of similar bodies accrete to form a (Chap 2, Class-XI, New NCERT) (IAS Pre 2002) fewer larger bodies in the form of planets. (a) The Earth is the densest of all planets in our Solar system. Solar System (b) The predominant element in the composition of Earth is Silicon. 8. Consider the following statements regarding the Solar System. (Chap 1, Class-VI, Old NCERT) (CGPSC Pre 2020) (c) The Sun contains 75% of the mass of the Solar system. 1. Mercury is the hottest planet in the Solar system. (d) The diameter of the Sun is 190 times that of the 2. Ganymede, satellite of Saturn, is the largest satellite Earth. in the solar system.  NCERT MCQs The Universe 05 3. Neptune is surrounded by methane gas rings of lots of gases and dust from the terrestrial planets. The sub-zero temperature. terrestrial planets are smaller and their lower gravity 4. Phobos and Deimos are two satellites of mars. could not hold the escaping gases. Which of the statements given above are correct? 11. Which among the following celestial objects will (a) 1 and 2 (b) 2 and 3 be found beyond the orbit of planet Neptune in (c) 3 and 4 (d) 1, 2, 3 and 4 the Solar System? (Chap 2, Class-XI, New NCERT) j Ans. (c) (a) Asteroids (b) Comet Exp. Statements (3) and (4) are correct regarding Solar (c) Dwarf Planets (d) Both ‘b’ and ‘c’ System. Neptune is surrounded by methane gas rings of sub-zero temperature. Mars has two small moons : j Ans. (d) Phobos and Deimos, which were discovered by Exp. Among the given celestial objects, Comet and American astronomer Asaph Hall in 1877. Dwarf Planets will be found beyond the orbit of Statements (1) and (2) are incorrect because Venus is Neptune in the Solar System. the hottest planet in the Solar System, not Mercury For instance, Pluto was previously considered as a because its dense atmosphere acts as a greenhouse and planet (until August 2006). However, at a meeting of the heats the surface to about 880°F. International Astronomical Union, it was decided that Ganymede is the satellite of Jupiter. It is the largest Pluto, like other recently found astronomical objects satellite in the Solar System. (2003 UB 313), should be referred to as a ‘Dwarf Planet’. 9. The planetoids, also known as asteroids, are Comets orbit around the Sun, but most are believed to planet-like objects that revolve around the Sun in inhabit in an area known as the Oort Cloud, far beyond our Solar System. These numerous small bodies the orbit of Pluto. are usually found between the orbits of which of While Asteroids belt is located roughly between the the following planets? (Chap 1, Class-VI, New NCERT) orbits of the planets Jupiter and Mars. (a) Earth and Mars (b) Mars and Jupiter 12. Which among the following statements can be (c) Jupiter and Saturn (d) Mercury and Venus considered as definitely true about the planets in j Ans. (b) Solar System? (Chap 2, Class-XI, New NCERT) Exp. The planetoids (also known as asteroids) are found 1. The asteroids are revolving around the Sun between between the orbits of Mars and Jupiter. They are rocky the orbits of terrestrial planets and Jovian planets. objects revolving around the Sun. Asteroids are made 2. The terrestrial planets in the Solar System are up of clay and silicate rocks and are dark in appearance. much smaller than the Jovian planets. They are known to be among the most ancient objects in the Solar System. 3. The atmosphere of Jovian planets is made up of oxygen and argon. 10. Consider the following statements about Codes terrestrial planets. (Chap 2, Class-XI, New NCERT) (a) 1 and 3 (b) 2 and 3 1. The terrestrial planets were formed in the close (c) 1 and 2 (d) All of these vicinity of the parent star where it was too cold for j Ans. (c) gases to condense to solid particles. Exp. Statements (1) and (2) are considered as definitely 2. The terrestrial planets are larger and their lower true about the planets in Solar System because out of gravity could not hold the escaping gases. the eight planets, Mercury, Venus, Earth and Mars are Which of the statement(s) given above is/are called as the inner planets as they lie between the Sun and the belt of asteroids. incorrect? The other four planets are called the outer planets. (a) Only 1 (b) Only 2 Alternatively, the first four are called terrestrial, (c) Both 1 and 2 (d) Neither 1 nor 2 meaning earth-like as they are made up of rock and j Ans. (c) metals, and have relatively high densities. Exp. Both the statements (1) and (2) are incorrect about The rest four are called Jovian or gas giant planets. terrestrial planets. The terrestrial planets were formed Jovian means Jupiter-like, most of them are much in the close vicinity of the parent star where it was too larger than the terrestrial planets. warm for gases to condense to solid particles. The solar Statement (3) is false because the atmosphere of Jovian wind was most intense, nearer the Sun; so, it blew off planets is made up of helium and hydrogen.  NCERT MCQs The Universe 06 Planets 16. This planet takes almost same time to rotate on its axis and revolve around the Sun in its fixed 13. Which of the following statements is/are correct orbit. Its shape and size is very much similar to regarding evolution of atmosphere and the Earth. Its orbital period is shorter than the hydrosphere? (Chap 2, Class-XI, New NCERT) Earth. Identify the planet from the information (a) During the cooling of the Earth, gases and water given above. (Chap 4, Class-X, NCERT) vapour were released from the interior solid Earth. (a) Mercury (b) Saturn (c) Uranus (d) Venus (b) The process through which the gases were outpoured from the interior is called degassing. j Ans. (d) (c) Continuous volcanic eruptions contributed water Exp. The given information is about planet Venus. It vapour and gases to the atmosphere. takes almost same time to rotate on its axis (243 days ) and revolve around the Sun (255 days) in its fixed orbit. (d) All of the above It also considered as ‘Earth’s-twin’ because its size and j Ans. (d) shape are very much similar to that of the Earth. Exp. All of the given statements are correct regarding evolution of atmosphere and hydrosphere. During the 17. Consider the following statements regarding light cooling of the Earth, gases and water vapour were year. (Chap 2, Class-XI, New NCERT) released from the interior of the earth by the mode of 1. Light travels at a speed of 3,00,000 km/second. volcanic eruptions. This started the evolution of the Therefore, the distance the light will travel in one present atmosphere. The early atmosphere largely year is taken to be one light year. contained water vapour, nitrogen, carbon dioxide, methane, ammonia and very little of free oxygen. The 2. The mean distance between the Sun and the process through which the gases were outpoured from Earth is 149,598,000 km. the interior is called degassing. 3. The diameters of individual galaxies range from Continuous volcanic eruptions contributed water 80,000-1,50,000 light years. vapour and gases to the atmosphere. As the Earth Which of the statement given above is/are Correct? cooled, the water vapour released started getting (a) Only 1 (b) 2 and 3 condensed. (c) 1 and 3 (d) 1, 2 and 3 14. Which one of the following planets has the j Ans. (d) largest number of natural satellites or moons? Exp. All the given statements are correct regarding (Chap 1, Class-VI, Old NCERT) (IAS Pre 2009) light year. A light year is a measure of distance. Light travels at a speed of 3,00,000 km/second. Considering (a) Jupiter (b) Mars this, the distance the light will travel in one year is (c) Saturn (d) Venus taken to be one light year. This equals to 9.4611012 km. j Ans. (c) The mean distance between the Sun and the Earth is Exp. Among the given options, Saturn has the largest 149,598,000 km. In terms of light years, it is 8.311 number of natural satellites. It has total of 82 satellites. minutes. The diameters of individual galaxies range The number of moons of other planets are Mercury 0, from 80,000-1,50,000 light years. Venus (0), Earth (1), Mars (2), Jupiter (79), Uranus (27) and Neptune (14). 18. Which of the statements is/are incorrect regarding formation of moon? 15. Which among the following planets is made up of (Chap-2 Class-XI, New NCERT) hydrogen and helium, with traces of methane, (a) The formation of moon, as a satellite of the Earth, is ammonia and water? (Chap 2, Class-XI, New NCERT) an outcome of’ ‘giant impact’ or what is described as (a) Mars (b) Jupiter ‘the big splat.’ (c) Mercury (d) Venus (b) A body of the size of one to three times that of mars collided into the Earth sometime shortly after the j Ans. (b) Earth was formed. Exp. The planet which is made up of hydrogen and helium, with traces of methane, ammonia and water is (c) Both ‘a’ and ‘b’ ‘Jupiter’. Saturn, Uranus and Neptune are Jovian (d) Neither ‘a’ nor ‘b’ planets. j Ans. (d) Exp. None of the statement is incorrect regarding formation of moon. The moon’s origin as a satellite of  NCERT MCQs The Universe 07 the Earth is the result of a ‘great impact,’ often known 21. Consider the following statements regarding as ‘the big splat.’ Shortly after the Earth was formed, a stages in the evolution of the present atmosphere. body, crashed with it that was the size of one to three (Chap 2, Class-XI, New NCERT) times of Mars. 1. The first stage is marked by the loss of primordial A big portion of the Earth was blown into space. About atmosphere. 4.44 billion years ago, a piece of the blasted material 2. In the second stage, the hot interior of the Earth was orbiting the Earth that the current moon. contributed to the evolution of the atmosphere. 19. Arrange the following planets in increasing 3. Finally, the composition of the atmosphere was order of their size? (Chap 1, Class-XI, New NCERT) modified by the living world through the process of (a) Mars, Earth, Uranus, Saturn photosynthesis. (b) Venus, Earth, Neptune, Saturn Which of the statements given above is/are correct? (c) Mars, Mercury, Venus, Earth (a) Only 1 (b) Only 2 (d) Both ‘a’ and ‘b’ (c) 1, 2 and 3 (d) 1 and 3 j Ans. (a) j Ans. (c) Exp. The correct arrangement of planets in increasing Exp. All the given statements regarding the stages of order of their size is Mars, Earth, Uranus and Saturn. evolution of present atmosphere are correct. There are The size of planets can be compared on the basis of the three stages in the evolution of the present their radius. atmosphere. The first stage is marked by the loss of The radius (Equatorial radius of Earth 6378.137 km primordial atmosphere. = 1) of the planets are Mercury- 0.383, Venus- 0.949, In the second stage, the hot interior of the Earth Earth- 1.000, Mars- 0.533, Jupiter-11.19, Saturn-9.460, contributed to the evolution of the atmosphere. Uranus- 4.11 and Neptune- 3.88. Finally, the composition of the atmosphere was modified by the living world through the process of 20. Which of the following factors have contributed photosynthesis. to the formation of terrestrial rocky planets? (Chap 2, Class-XI, New NCERT) 22. Which among the following terms is used to 1. Closeness to the parent star describe small bodies that develop into large 2. Solar winds planets due to processes of cohesion? 3. Higher gravity (Chap 2, Class-XI, New NCERT) Codes (a) Proto planets (b) Planetoids (a) 1 and 2 (b) 2 and 3 (c) Planetesimals (d) Plutoids (c) 1 and 3 (d) All of these j Ans. (c) j Ans. (a) Exp. ‘Planetesimals’ is the term used to describe small Exp. Closeness to the parent star and solar winds have bodies that develop into large planets due to process of contributed to the formation of terrestrial rocky cohesion. planets. The terrestrial planets were formed in the In the second stage of formation of planets, the gas cloud close vicinity of the parent star where it was too warm starts getting condensed and the matter around the core for gases to condense to solid particles. develops into small rounded objects. These small Jovian planets were formed at quite a distant location. rounded objects by the process of cohesion develop into The Solar wind was most intense, nearer the Sun; so, it larger planets which is called planetesimals. blew off lots of gases and dust from the terrestrial Protoplanets are small celestial objects that are the size planets. The solar winds were not all that intense to of a moon or a big bigger than that. cause similar removal of gases from the Jovian planets. Planetoid is another term for asteroids. It is also known The terrestrial planets are smaller and their low as minor planets. gravity could not hold the escaping gases. Plutoids are celestial bodies in orbit around the Sun. They are basically dwarf planets that are farther from Sun.  03 The Earth New NCERT Class VI (The Earth in the Solar System, Globe: Latitudes and Longitudes, Motions of the Earth), Old NCERT Class VI (The Earth in the Solar System, Latitudes and Longitudes, Motions of the Earth), New NCERT Class XI (The Origin and Evolution of the Earth) Old NCERT Class XI (The Earth: Its Origin and Evolution) Origin of Earth 3. Which among the following statements are correct about the Earth in its primitive form? 1. Consider the following Assertion (A) and (Chap 2, Class-XI, Old NCERT) Reason (R) and choose the correct code. 1. It was a cloud of dust and gases in its initial stages. (Chap 1, Class-VI, New NCERT) 2. All the gases were concentrated in the core of Earth. Assertion (A) The shape of the Earth is Geoid. 3. Life was present on the land in initial stages. Reason (R) The Earth is slightly flattened at the 4. It took 4,600 million years in formation of Earth. poles not at the Equator. Codes Codes (a) 1, 2 and 3 (b) 2 and 4 (a) Both A and R are true and R is the correct (c) 1 and 4 (d) All of the above explanation of A. j Ans. (c) (b) Both A and R are true, but R is not the correct explanation of A. Exp. Statements (1) and (4) are correct about the Earth in its primitive form because the Sun is surrounded by solar (c) A is true, but R is false. nebula (a giant cloud) containing mostly, hydrogen and (d) A is false, but R is true. helium along with dust. It took around 4,600 million years j Ans. (a) for the evolution of life on the surface of the planet Earth. Exp. Both Assertion (A) and Reason (R) are true and Planet Earth initially was a barren, rocky and hot object Reason (R) is the correct explanation of Assertion with a thin atmosphere of hydrogen and helium. Hence, (A). The Earth is slightly flattened at the poles not at life was not present on the land in initial stages. Equator. That is why; its shape is described as a Statements (2) and (3) are incorrect as the Earth was mostly Geoid that means an Earth-like shape. in a volatile state during its primordial stage. Due to gradual increase in density, the temperature inside the 2. Which of the following statements is incorrect Earth increased. As a result, the material inside the Earth about the Earth? (Chap 1, Class-VI, Old NCERT) started getting separated depending on their densities. (a) It is spherical in shape. There are no traces of life to be present on the land in (b) The poles of Earth are flat. initial stages. (c) It is located nearest to the Sun. 4. Many scientists gave the early theories of formation (d) It is the only planet where life exists. of Earth. Which of the following proposed that a j Ans. (c) wandering star was responsible for formation of Exp. Statement (c) is incorrect about the Earth as it Earth by separation of material from solar surface? is the third nearest planet to the Sun. Earth is (Chap 2, Class-XI, Old NCERT) nearest to Venus and Mars while Mercury is nearest (a) Chamberlain and Moulton (b) Harold Jeffery to the Sun. (c) Laplace (d) Otto Schmidt  NCERT MCQs The Earth 09 j Ans. (a) Earth travels fastest at the perihelion (point of orbit Exp. Chamberlain and Moulton proposed that a closet to Sun) gradually slowing down until it reaches wandering star was responsible for formation of the the aphelion (point of orbit farthest from Sun) where it Earth by separation of material from solar surface. increases its speed until the perihelion. As the passing star moved away, the material separated 7. The stages of formation of the Earth are given in from the solar surface continued to revolve around the the options given below. Arrange the stages in a Sun and it slowly condensed into planets. correct sequence and choose the correct answer 5. Which of the following views was supported by using the codes given below. Carl Weizsacker and Otto Schmidt about the (Chap 2, Class-XI, Old NCERT) origin of Earth? (Chap 2, Class-XI, Old NCERT) 1. Formation of ridges and basins 1. Sun was surrounded by a nebula of hydrogen and 2. Swirling ball of dust and clouds helium. 3. Formation of crust of the Earth 2. Collision and friction between gas particles 4. Floating of gases to form atmosphere formed the planets. 5. Formation of oceans 3. Planets were formed by the process of Codes disintegration. (a) 2, 1, 3, 5, 4 (b) 2, 3, 1, 4, 5 Codes (c) 1, 2, 4, 5, 2 (d) 5, 1, 3, 4, 2 (a) 1 and 2 (b) 2 and 3 j Ans. (b) (c) 1 and 3 (d) All of these Exp. Option (b) is the correct sequence. At the j Ans. (a) beginning, Earth was a giant ball of dust and cloud Exp. Statements (1) and (2) were supported by Otto known as Nebula. Schmidt of Russia and Carl Weizsacker of Germany. After that, through the process of accretion, the planet They revised the ‘nebular hypothesis’, that was Earth started to form. This process allowed heavier differing in details. They considered that the Sun was materials (like iron) to sink towards the centre of the surrounded by solar nebula containing mostly the Earth and the lighter ones to move towards the surface. hydrogen and helium along with dust. The crust started to form along with ridges and basins. Statement (3) is not correct as planets were formed In the next stage, the Earth’s atmosphere started to through the process of accretion not by the process of form with floating gases and at last after 500 million disintegration. years from the formation of the Earth, the oceans started to form. 6. Consider the following statements. (Chap 2, Class- XI, Old NCERT) (UPPSC Pre 2000) 8. Which among the following is the earliest theory 1. The Northern end of the Earth’s axis is called to describe the formation of Earth? North Pole. (a) Big Bang Theory (Chap 2, Class-XI, New NCERT) 2. 45° latitude is half of the length of the equator. (b) Expanding Universe Hypothesis 3. Earth’s axis is Parallel. (c) Nebular Hypothesis 4. The Earth’s speed of revolution is faster in (d) Steady State Hypothesis aphelion position. j Ans. (c) Which of the statement(s) given above are correct? Exp. Earliest theory to describe the formation of Earth (a) 1 and 2 (b) 2 and 3 (c) 3 and 4 (d) 1 and 3 is known as Nebular Hypothesis. A large number of j Ans. (d) hypotheses were put forth by different philosophers and scientists regarding the origin of the Earth. One of Exp. Statements (1) and (3) are correct. The North Pole the earlier and popular arguments was given by is the Northern point of Earth i.e. northern end of the German philosopher Immanuel Kant. Earth’s axis which is called North Pole. Both the axis of 1° Mathematician Laplace revised it in 1796 and named as the Earth are tilted at an angle of 23 and are parallel Nebular Hypothesis. Both Big Bang and Expanding 2 Universe Hypothesis are related to the origin of to each other. universe and Steady State Hypothesis state that the Statements (2) and (4) are incorrect because the length density of matter in the expanding universe remains of 45° Parallel line is 2833.039 km, while the length of unchanged over time because of the continuous creation the equator is 40075.62 km. of matter.  NCERT MCQs The Earth 10 9. Consider the following Assertion (A) and Codes Reason (R) and choose the correct code. (a) 1 and 2 (b) Only 2 (Chap 2, Class-XI, New NCERT) (IAS Pre 2003) (c) Only 3 (d) 1, 2 and 3 Assertion (A) Moving from one place on earth to j Ans. (d) another place of high latitude, the weight of an Exp. All the statements are correct about the evolution object decreases. of Earth’s lithosphere. Reason (R) Earth is not a perfect sphere. The Earth was mostly in a volatile state during its Codes primordial stage. (a) Both A and R are true, and R is the correct Due to gradual increase in density, the temperature explanation of A. inside increased. As a result, the material inside started getting separated depending on their densities. (b) Both A and R are true, but R is not the correct explanation of A. This allowed heavier materials (like iron) to sink towards the centre of the Earth and the lighter ones to move (c) A is true, but R is false towards the surface. (d) A is false, but R is true With passage of time, it cooled further and solidified j Ans. (d) and condensed into a smaller size. This later led to the Exp. Assertion (A) is false and Reason (R) is true. development of the outer surface in the form of a crust. The centrifugal force generated by the Earth’s axis rotation is maximum at equator. As the result of this 12. During the evolution of the Earth, the hydrogen force, the weight of any object is minimum at Equator and helium gases of early atmosphere were and maximum at poles and also increases towards high stripped off by, which of the following? latitude. Earth is not perfect sphere because it is (Chap 2, Class-XI, New NCERT) slightly flattened at the poles and not the Equator. (a) High density of Earth (b) Solar winds (c) Solar spots (d) Rainfall 10. According to the early theories of Earth formation, the accretion of, which of the following materials j Ans. (b) led to the formation of planet Earth? Exp. During the evolution of the Earth, the hydrogen and helium gases of early atmosphere were stripped off, (a) Nitrogen (Chap 2, Class-XI, New NCERT) as a result of the solar winds. This happened not only in (b) Hydrogen and helium the Earth, but also in all the terrestrial planets, which (c) Silicon and oxygen were supposed to have lost their primordial atmosphere (d) Iron and nickel through the impact of solar winds. j Ans. (b) 13. The major components of the present atmosphere Exp. According to the early theories of Earth formation, of Earth have been released from, which of the the accretion of hydrogen and helium gases led to the formation of planet Earth. They initially formed the following sources? (Chap 2, Class-XI, New NCERT) Earth’s surface. The early atmosphere with hydrogen (a) The Sun in Solar System and helium is supposed to have been stripped off as a (b) A large mass of rock revolving around the Earth result of intense solar wind. This happened not only in (c) Interior of the Earth Earth, but also in all the terrestrial planets, which were (d) Volcanic eruptions supposed to have lost their primordial atmosphere through the impact of solar winds. j Ans. (c) Exp. The major components of the present atmosphere 11. Which among the following statements about the of Earth have been released from interior of the Earth evolution of Earth’s lithosphere is correct? because during the cooling of the Earth, gases and water (Chap 2, Class-XI, New NCERT) vapour were released from the interior of solid Earth. 1. The materials inside the lithosphere have This started the evolution of the present atmosphere. arranged according to density differences. 14. Which among the following were not the 2. During its formation, the heavier materials have components of Earth’s atmosphere during its sunk towards the centre of the Earth. origin? (Chap 2, Class-XI, New NCERT) 3. During its formation, the increase in density inside the Earth has resulted is increase in 1. Carbon dioxide 2. Helium temperature. 3. Hydrogen 4. Oxygen  NCERT MCQs The Earth 11 Codes 17. Dinosaurs got extinct from the Earth during (a) 1, 2 and 3 (b) 1 and 4 which of the following periods? (c) 2 and 3 (d) 1, 2 and 4 (Chap 2, Class-XI, New NCERT) j Ans. (b) (a) Jurassic period (b) Carboniferous period Exp. Carbon dioxide and oxygen were not the (c) Triassic period (d) Cretaceous period components of Earth’s atmosphere during its origin. j Ans. (d) Only hydrogen and helium are the gases, which were Exp. Dinosaurs got extinct from Earth. In Cretaceous found at the primordial stage of the Earth’s period (65 - 144 million years ago), which is the part of atmosphere. Mesozoic era. It is the last period of Mesozoic era. 15. Which of the following pairs are matched 18. During, which of the following periods, the first correctly? (Chap 2, Class-XI, New NCERT) fish appeared in the oceans? 1. Origin of life on Earth – 3,800 million years ago (Chap 2, Class-XI, New NCERT) 2. Photosynthesis begins – 2,500-3,000 million years (a) Cambrian period (b) Ordovician period ago (c) Permian period (d) Devonian period 3. Release of oxygen in atmosphere – 2,000 million j Ans. (b) years ago Codes Exp. In Ordovician period, the first fish appeared in the oceans. The Ordovician period is a part of (a) 1 and 2 (b) 2 and 3 Palaeozoic era. The age of this period is 438 to (c) 1 and 3 (d) All of these 505 million years ago. j Ans. (d) Exp. All of the pairs are matched correctly as the origin 19. Arrange the following periods in the correct of life on Earth began 3,800 million years ago. It was sequence of the Geological Time Scale. just after the formation of ocean around 4,000 million (Chap 2, Class-XI, New NCERT) years ago. 1. Tertiary Period Around 2,500-3,000 million years ago, the process of 2. Carboniferous photosynthesis evolved. Then the oceans began to have 3. Cambrian Period the contribution of oxygen through this process. 4. Jurassic Period Eventually, oceans were saturated with oxygen and Codes 2,000 million years ago, the oxygen began to flood the (a) 1, 2, 3, 4 (b) 3, 2, 4, 1 atmosphere. (c) 2, 3, 4, 1 (d) 1, 3, 2, 4 j Ans. (b) Geological Time Scale Exp. Cambrian period is the oldest period among the 16. The first plant on the Earth appeared in, which given options as it existed 505-570 million years ago. of the following Era? (Chap 2, Class-XI, New NCERT) Then, the next is Carboniferous period as it existed 286-360 million years ago. (a) Mesozoic Era (b) Palaeozoic Era The third is Jurassic period, which existed 286-360 (c) Cainozoic Era (d) Pre-Cambrian Era million years ago. j Ans. (b) The fourth is Tertiary period, which is the youngest Exp. The first plant on Earth appeared in Palaeozoic among the given options as it existed 2-65 million years Era. This era was present 245 to 570 million years ago. ago. This era has been divided into six periods. These are Permian, Carboniferous, Devonian, Silurian, 20. Match the following lists correctly and choose the Ordovician and Cambrian. correct code. (Chap 2, Class-XI, New NCERT) The major events in this era are List I List II Reptile Dominate-Replace amphibians (Period) (Major Event) First Reptiles A. Carboniferous 1. Early human ancestors Vertebrates: Coal beds amphibians B. Silurian 2. Appearance of first reptiles First trace of life on land: Plants First fish C. Jurassic 3. First traces of life on land No terrestrial life : Marine invertebrate D. Tertiary 4. Dominance of dinosaurs  NCERT MCQs The Earth 12 Codes Motions of Earth A B C D A B C D (a) 1 2 4 3 (b) 2 3 4 1 22. Consider the following statements. (c) 3 1 2 4 (d) 2 4 1 3 (Chap 4, Class-VI, Old NCERT) (IAS Pre 2018) j Ans. (b) 1. The Earth’s magnetic field has reversed every few hundred thousand years. Exp. The correct matching is A-2, B-3, C-4, D-1. 2. When the Earth was created more than 4000 Carboniferous It is a part of Palaeozoic era. The age of Carboniferous period is 286-360 million years. The million years ago, there was 54% oxygen and no major event of this period is the appearance of first carbon dioxide. reptiles. 3. When living organisms originated, they modified Silurian It is also a part of Palaeozoic era. The age of the early atmosphere of the Earth. Silurian period is 408 - 438 million years before present. Which of the statement(s) given above is/are correct? The major event of this period is the first traces of life (a) Only 1 (b) 2 and 3 (c) 1 and 3 (d) 1, 2 and 3 on land. j Ans. (c) Jurassic It is a part of Mesozoic era. The age of Jurassic Exp. Statements (1) and (3) are correct. The magnetic period is 144-208 million years before present. The field of Earth has reversed every few hundred thousand major event of this period is the dominance of years. When living organisms originated, they modified dinosaurs. the early atmosphere of the Earth. Tertiary It is a part of Cenozoic era. The age of this Statement (2) is not correct as the Earth is period is 2–65 million years. The major event of this approximately 5 billion years old and the oxygen was period is early human ancestors. completely absent at that time. 21. Match the following lists correctly and choose the 23. Which of the following statements is/are correct correct code. (Chap 2, Class-XI, New NCERT) about the revolution of Earth around the Sun? List I (Epoch) List II (Age) (Chap 3, Class-VI, New NCERT) A. Holocene 1. 24-37 million years (a) The orbit of the Earth around the Sun is helical in shape. B. Pliocene 2. 0-10,000 years (b) During its revolution, the inclination of the Earth C. Oligocene 3. 37-58 million years remains constant. D. Eocene 4. 2-5 million years (c) The shape of the Earth changes during its revolution. (d) All of the above Codes A B C D A B C D j Ans. (b) (a) 1 2 4 3 (b) 2 3 4 1 Exp. Statement (b) is correct about the revolution of (c) 3 1 2 4 (d) 2 4 1 3 Earth around the Sun. The movement of the Earth around the Sun is a fixed path or orbit is called j Ans. (d) Revolution. The axis of the Earth which is an imaginary Exp. The correct matching is A-2, B-4, C-1, D-3. 1° line makes an angle of 66 with the orbital plane. Holocene It is a part of Quaternary period. The age of 2 Holocene Epoch is 0-10,000 years. The major event of The orbit of the Earth around the Sun is an elliptical this epoch is the development of modern man. orbit. Throughout its orbit, the Earth is inclined in the Pliocene It is a part of Tertiary period. The age of same direction. Pliocene epoch is 2-5 million years before present. The shape of the Earth does not change during The major event in this time is emerging of early human Revolution. The Revolution is responsible for change in ancestor. climate. Oligocene It is also a part of Tertiary period. The age of Oligocene epoch is 24-37 million years before present. 24. The Earth rotates on its inclined axis in, which of The major event of this period is the emerging of the following directions? (Chap 4, Class-VI, Old NCERT) anthropoid ape. (a) From East to West throughout the year Eocene It is a part of Tertiary period. The age of Eocene (b) From West to East throughout the year epoch is 37-58 million years before present. The major (c) East to West in summers and West to East in winters event of this period is the emerging of rabbit and hare. (d) East to West in winters and West to East in summers  NCERT MCQs The Earth 13 j Ans. (b) Exp. If the Earth stops rotating on its axis then there Exp. The Earth rotates on its inclined axis from West to will be complete day on one side. The portion of the East throughout the year. Rotation is the movement of Earth facing the Sun would always experience day. It the Earth on its axis. The Earth takes about 24 hours to will bring continuous warmth to the region. The other complete one rotation around its axis and it moves from half would remain in darkness and be freezing cold all West to East throughout the year. The period of the time. Life would not have been possible in such rotation is known as the Earth day. extreme conditions. 25. Consider the following statements about Earth’s 28. Different places on the Earth experience sunrise, inclined axis. (Chap 4, Class-VI, Old NCERT) noon, sunset and midnight at the same time. Which of the following most appropriately 1. The axis of Earth is an imaginary line. explains this phenomenon? 2. The axis of Earth coincides with the circle of (Chap 4 , Class-VI, Old NCERT) illumination. (a) Revolution of the Earth around the Sun 3. The axis is tilted at 23 1/2° to the orbital plane of (b) Rotation of the Earth on its axis Earth. (c) Axial tilt of the Earth Which of the statement(s) given above is/are correct? (d) Earth’s elliptical orbit (a) 1 and 2 (b) Only 2 j Ans. (b) (c) Only 1 (d) All of these Exp. Different places on the Earth experience sunrise, j Ans. (c) noon, sunset and midnight at the same time due to Exp. Statement (1) is correct about Earth’s inclined axis rotation of the Earth on its axis. The Earth’s axis runs because Earth’s axis is an imaginary pole or line passing from the North Pole to the South Pole. The Earth takes through the center of the Earth and makes an angle of 24 hours or one day, to make one complete rotation 66½° with its orbital plane. around this invisible line. As the Earth rotates, each Statements (2) and (3) are incorrect because the circle area of its surface gets a turn to face and be warmed by that divides the day from night on the globe is called the the Sun. This is important to all life forms on the Earth. circle of illumination. This circle does not coincide with the axis. Also the axis is tilted at 66 ½° to the orbital 29. Which of the following statements is/are correct plane of Earth. regarding Earth’s revolution around the sun? (Chap 4, Class-VI, Old NCERT) 26. It is because of the Earth’s rotation on its axis 1. The Earth’s movement around the Sun in its orbit that there is day and night in regular succession is called revolution. in all parts of Earth. Days and nights on the 2. The Earth’s revolution is responsible for Earth are divided by, which of the following occurrence of leap year on Earth. circles? (Chap 3, Class-VI, New NCERT) Codes (a) Circle of ellipse (b) Circle of inclination (a) Only 1 (b) Only 2 (c) Circle of illumination (d) Circle of division (c) Both 1 and 2 (d) Neither 1 nor 2 j Ans. (c) j Ans. (c) Exp. Days and nights on the Earth are divided by circle Exp. Both the statements (1) and (2) are correct of illumination. The imaginary line that separates day regarding Earth’s revolution around the sun. from night on Earth is called the circle of illumination. The Earth’s movement around the Sun in its orbit is It is basically the region that is experiencing sunshine. called revolution. It takes 365 1/4 days (one year) to The circle of illumination cuts all latitudes into half on revolve around the Sun. We consider it a year, as the spring and autumnal equinoxes. consisting of 365 days only and ignore six hours for the sake of convenience. Six hours saved every year are 27. What would happen if the Earth stops rotating on added to make one day (24 hours) over a span of four its axis? (Chap 4, Class-VI, Old NCERT) years. (a) There will be no seasons. This surplus day is added to the month of February. (b) There will be complete day on one side. Thus, every fourth year, February is of 29 days instead (c) The crust of Earth will melt. of 28 days. Such a year with 366 days is called a leap (d) The atmosphere of Earth will disappear. year. Thus, the Earth’s revolution is responsible for occurrence of leap year on Earth. j Ans. (b)  NCERT MCQs The Earth 14 30. Consider the following statements about the Statement (2) is incorrect because when the Southern revolution of Earth. (Chap 4, Class-VI, Old NCERT) Hemisphere is tilted towards the Sun, the South Pole has 24 hours night. 1. The Earth’s revolution takes place in an elliptical orbit. 32. Match the following lists correctly and choose the 2. The Earth rotates from West to East. correct code. (Chap 3, Class-VI, New NCERT) 3. Revolution of Earth on its tilted axis causes List I (Date) List II (Event) formation of seasons. A. 21st June 1. Summer Solstice Which of the statement(s) given above is/are correct? B. 22nd December 2. Autumn Equinox (a) 1 and 2 (b) 2 and 3 C. 23rd September 3. Winter Solstice (c) 1 and 3 (d) All of these D. 21st March 4. Spring Equinox j Ans. (d) Codes Exp. All the statements are correct about the revolution A B C D A B C D of Earth. The Earth takes 365¼ days (one year) to (a) 1 2 4 3 (b) 1 3 2 4 revolve around the Sun in an elliptical orbit. (c) 3 1 2 4 (d) 3 4 1 2 The Earth rotates on its own axis and it rotates in the Eastward direction and in a counter-clockwise motion. j Ans. (b) So, the direction of the Earth’s rotation is considered Exp. The correct matching is A-1, B-3, C-2, D-4. from West to East. 21st June, the Southern Hemisphere experiences On the The revolution of Earth on its tilted axis causes winter season and it is summer in the Northern formation of seasons because change of seasons is the hemisphere. At that point of time, the position of the result of changing in the position of the Earth around Earth on 21st June is called the Summer Solstice. the Sun. On 22nd December, the Tropic of Capricorn receives direct rays of the Sun as the South Pole tilted towards it. 31. Consider the following statements about the As the Sun’s rays fall vertically at the Tropic of revolution of Earth and it associated effects. Capricorn, a larger portion of the Southern Hemisphere (Chap 4, Class-VI, Old NCERT) gets light. This position of the Earth is called the Winter 1. When the Northern Hemisphere is tilted towards Solstice. the Sun, days are longer and nights are shorter in On 23rd September, direct rays of the Sun fall on the Northern Hemisphere. equator. This is called an equinox. At this time, it is 2. When the Southern Hemisphere is tilted towards autumn season in the Northern Hemisphere and spring the Sun, the North Pole has 24 hours day. season in the Southern Hemisphere. It is called as 3. When the Southern Hemisphere is tilted towards Autumn Equinox. the Sun, the North Pole has 24 hours night. 21st March is opposite case on 21st March, when it is Which of the statements given above is/are spring in the Northern Hemisphere and autumn in the Southern Hemisphere. It is also known as Spring correct? Equinox. (a) 1 and 2 (b) Only 2 (c) 2 and 3 (d) 1 and 3 j Ans. (d) 33. On which of the following days, the length of day Exp. Statements (1) and (3) are correct about the and night on the North Pole and South Pole will revolution of Earth and it associated effects because be exactly same? (Chap 4, Class-VI, Old NCERT) when 21st June, the Northern Hemisphere is tilted (a) 23rd December (b) 22nd September towards the Sun. The rays of the Sun fall directly on the (c) 21st March (d) 31st December Tropic of Cancer. As a result, it is summer in the regions North of the equator. The longest day and the j Ans. (c) shortest night at these places occur on 21st June. On Exp. On 21st March, the length of day and night on the 22nd December, the Tropic of Capricorn receives North Pole and South Pole will be exactly same. During direct rays of the Sun as the South Pole is tilted towards the spring and autumn equinoxes, i.e., on 21st March it. Therefore, it is summer in the Southern Hemisphere and 23rd September, the Sun is exactly overhead the with longer days and shorter nights. The reverse Equator and the North and South Poles lie at an equal happens in the Northern Hemisphere and the North distance from the Sun. This is the reason, days and Pole has 24 hours night. nights are of equal length throughout the world on these two days.  NCERT MCQs The Earth 15 34. The rotation of Earth in its elliptical orbit causes regions of the equator. The longest day and the shortest seasons on Earth. Seasons differ in both the night at these places occur on 21st June. Northern Hemisphere and the Southern At this time in the Southern Hemisphere all these Hemisphere. Which of the following statements conditions are reversed. It is winter season there. The nights are longer than the days. This position of the about the seasons in Southern and Northern Earth is called the Summer Solstice. Hemispheres is/are correct? (Chap 3, Class-VI, New NCERT) 36. The Winter Solstice occurs on 22nd December. 1. In the month of September, the Southern During Winter Solstice, which of the following Hemisphere has spring season. phenomenon can be observed in the Southern 2. In the month of June, the Northern Hemisphere Hemisphere? (Chap 3, Class-VI, New NCERT) has summer season. 3. In the month of December, the Southern 1. The length of days will be longer in the Southern Hemisphere has winter season. Hemisphere. Codes 2. Southern Hemisphere experiences winter season. (a) 1 and 3 (b) 2 and 3 3. The South Pole has 24 hours day for 6 months. (c) Only 2 (d) 1 and 2 Codes j Ans. (d) (a) 1 and 2 (b) 2 and 3 Exp. Statements (1) and (2) are correct about the (c) 1 and 3 (d) All of these seasons in Southern and Northern Hemisphere. j Ans. (c) As on 21st March and 23rd September, direct rays of the Exp. Phenomena mentioned in Statements (1) and (3) Sun fall on the equator. At this position, neither of the can be observed in the Southern Hemisphere. poles is tilted towards the Sun; so, the whole Earth During Winter Solstice, the length of days will be experiences equal days and equal nights. On 23rd longer in the Southern Hemisphere and the South Pole September, it is autumn season in the Northern has 24 hours day for 6 months. This is because on 22nd Hemisphere and spring season in the Southern December, the Tropic of Capricorn receives direct rays Hemisphere. of the Sun as the South Pole tilts towards it. Also in Northern Hemisphere, the longest day and the Therefore, it is summer in the Southern Hemisphere shortest night take places on 21st June. Hence, we can with longer days and shorter nights. This position of the conclude that in the month of June, the Northern Earth is called the Winter Solstice. Hemisphere has summer season. Phenomenon mentioned in statement (2) cannot be Statement (3) is incorrect as in the month of December, observed as during this time Southern Hemisphere the Southern Hemisphere has summer season while the experiences summer season and Northern Hemisphere Northern Hemisphere has winter season. experiences winter season. 35. Which of the following statements is incorrect 37. Consider the following Assertion (A) and Reason about the Summer Solstice? (R) and choose the correct code. (Chap 3, Class-VI, New NCERT) (Chap 3, Class-VI, New NCERT) (a) The North Pole of Earth has 24 hours daylight. Assertion (A) All the places on Earth will have (b) The South Pole has 24 hours night. equal length of days and nights on 23rd (c) The Northern Hemisphere has autumn season. September. (d) The Southern Hemisphere has winter season. Reason (R) The rays of the Sun fall directly on the j Ans. (c) Equator during Equinox. Exp. Statement (c) is incorrect about the summer Codes solstice because on 21st June, the Northern (a) Both A and R are true and R is the correct Hemisphere is tilted towards the Sun. The rays of explanation of A the Sun fall directly on the Tropic of Cancer. As a result, these areas receive more heat. The areas near (b) Both A and R are true, but R is not the correct the poles receive less heat as the rays of the Sun are explanation of A slanting. (c) A is true, but R is false Since, a large portion of the Northern Hemisphere is (d) A is false, but R is true getting light from the Sun, it is summer in the north j Ans. (a)  NCERT MCQs The Earth 16 Exp. Both Assertion (A) and Reason (R) are true and If the Earth stops rotating, the portion of the Earth Reason (R) is the correct explanation of Assertion (A). facing the Sun would always experience day, thus because on 21st March and 23rd September, direct rays bringing continuous warmth to the region. The other of the Sun fall on the equator. At this position, neither half would remain in darkness and be freezing cold all of the poles is tilted towards the Sun, so the whole the time. Earth experiences equal days and equal nights. This is Earth’s rotates at an axial tilt of 66 1/2° from the plane of called an equinox. Earth’s orbit. 38. During certain period of the year, the rays of the The Moon Sun are falling directly over the Tropic of Cancer (23 1/2° N). Which of the following is 40. Which of the following statements can be most likely to occur during this period? considered as certainly true about the Moon? (Chap 4, Class-VI, Old NCERT) (Chap 1, Class-VI, Old NCERT) (a) Northern Hemisphere will have longer days and (a) The diameter of Moon is one-fifth of the Earth. shorter nights. (b) A person on Earth will always see the same side of (b) There will be 24 hour day on the North Pole. the Moon. (c) The revolution period of Moon is more than the (c) The length of days and nights will be equal at all rotation period. places. (d) Water and soil are present in abundant quantities on (d) Both ‘a’ and ‘ b’ Moon. j Ans. (d) j Ans. (b) Exp. During the period mentioned in question, Exp. Statement (b) can be considered as certainly true Northern Hemisphere will have longer days and about the moon because Earth has only one satellite, shorter nights. Also there will be 24 hour day on the i.e., the Moon. Its diameter is only one-quarter to that North Pole because on 21st June when the rays of the of the Earth. Sun fall directly on the Tropic of Cancer, Northern Hemisphere receive more heat. Since, a large portion It appears so big because it is nearer to our planet than of the Northern Hemisphere is getting light from the other celestial bodies. It is about 3,84,400 km away from Sun, it is summer in the regions North of the equator us. It revolves around the Earth and rotates about its with longer days and shorter nights. own axis in about the same time, due to, which only one side of the Moon is visible to us. Water and soil are not Statement (c) is incorrect because during this time, days present on the Moon. Hence, the Moon does not have are longer in Northern Hemisphere and nights are favourable conditions for life. shorter but in Southern Hemisphere all these conditions are reversed. Thus, the length of days and nights are 41. Consider the following statements about the equal at all places when the rays of the Sun are falling Moon. (Chap 1, Class-VI, Old NCERT) directly over the Tropic of Cancer. 1. The Moon revolves around the Earth in a fixed 39. Which among the following statements are path. incorrect about t