NCERT Solutions for Class 6 Social Science - The Earth Our Habitat

Chapter 1 : The Earth in the Solar System

• Solar system is formed by the family of sun- the planets, satellites, asteroids and meteoroids.
• The different patterns in sky formed by the group of stars are called constellation.
• The moon, sun and other shining objects in night sky are called celestial bodies.
• Stars twinkle and are made up of gases.
• Celestial bodies that do not have their own heat and lights and use the light of stars are called planets.
• There are 8 planets in our solar system. Jupiter is the largest planet and mercury is the smallest planet.
• Planets revolves around the sun in a fixed path called orbit.
• Earth is called a unique planet because it has life supporting condition. It is neither too hot or nor too cold. Water and air are found only in Earth.
• 2/3^rd of the earth’s surface is covered by water, hence earth is called blue planet.
• Satellite which revolves around planet is called moon.
• Asteroids numerous tiny bodies which moves around sun.
• Meteoroids are pieces of rocks which moves around sun.
• A huge system formed by stars, clouds, dust and gases is called galaxy.
• Millions of different galaxies makes up the universe. 

Chapter 2 : Globe Latitudes and Longitudes

• Globe is a exact miniature model of the Earth.
• Equator is an imaginary line which passes through the center of the Earth and divides the Earth into equal parts: The Northern Hemisphere and the Southern Hemisphere.
• There are parallel circles from equator towards the poles known as parallel of latitudes.
• Four important parallels of latitudes are: 23 ½◦ N (Tropic of Cancer), 23 ½◦ S is Tropic of Capricorn, 66 ½◦ N is Arctic circle and 66 ½◦ S is Antarctic circle.
• There are three heat zones of Earth: Torrid zone, Temperate zone and Frigid zone.
• The semicircles from North pole to South pole are called meridian of Longitudes.
• Equator is 0◦ Latitude whereas prime meridian is 0◦ Longitude.
• Prime meridian also divides the Earth into two equal halves: The Eastern Hemisphere and The Western Hemisphere.
• The time at 82 ½◦ E longitude in India is taken as the standard time of the whole country.
• There are 180 meridian or the meridian of the longitudes and 180 latitudes or parallel of latitudes are present.     

Chapter 3 : Motions of the Earth

• Earth practices two types of motion: Rotation and Revolution.
• Axis is an imaginary line which makes an angle of 66 ½◦.
• Days and nights are caused due to rotation.
• Seasons are caused due to revolution.
• Circle of illumination is the circle which divides day from night on globe.
• Leap year comes after every 4 years and at that time, February has 29 days. It means, earth usually have 365 days but in the leap year earth will have 366 days.
• The longest day and shortest night is observed on 21^st June.
• 21^st March and 23^rd September experiences equal day and night which is known as equinox.

Chapter 4 : Maps

• Map is a drawing according to the scale.
• There are three types of map: Political, physical and thematic.
• Physical maps are also called relief maps.
• There are three components of map: distance, direction and symbol.
• Scale is a ratio of distance shown in map and in actual.
• Direction is represented by letter ‘N’.
• Four cardinal points are: east, west, north and south.
• Conventional symbols are used in maps to represent different features like river, roads, temple, trees, railway, grave etc. And, various colours too are used.
• Sketch is a rough drawing of a spot which is not according to scale.
• Plan is a drawing a small scale on a large scale.

Chapter 5 : Major Domains of the Earth

• In earth, there are three components of environment: Lithosphere, Atmosphere and Hydrosphere.
• Solid portion of the earth is lithosphere, water portion of the earth is hydrosphere and air portion of the earth is known as atmosphere.
• The narrow zone of contact between air, water and land is called biosphere.
• The large landmasses are continents and large water bodies are oceans.
• There are seven continents on earth: Asia, America, Africa, North America, South America, Australia and Antarctica.
• Research stations of India in Antarctica are Maitri and Dakshin gangotri.
• More than 71% of Earth’s surface is covered with water and 29% with land.
• There are five oceans on the Earth: Pacific Ocean, Indian Ocean, Arctic Ocean, Antarctic Ocean and Atlantic Ocean.
• Mariana Trench in Pacific Ocean is the deepest point on Earth.
• Indian Ocean is the only Ocean which is named after a country ‘India’.
• 78% of Nitrogen is present in atmosphere, 21% oxygen and 1% other gases like CO₂, argon, vapours etc.
• The largest continent is Asia and smallest is Australia. The largest Ocean is Pacific ocean and smallest is Arctic ocean.
• Increase in the amount of CO₂ increases global temperature and this is called as global warming.

Chapter 6 : Major Landforms of the Earth

• Landforms are formed by two major processes: Internal process and External process.
• The wearing away of soil from the surface of Earth is known as soil erosion.
• The surface is lowered by the process of erosion and rebuilt by the process of deposition.
• Mountains, Plateaus and Plains are the group of different landforms which are dependent on the Elevation and slopes.
• Rivers are formed by melting of glaciers.
• Mountains are of three types: Block mountains, fold mountains and volcanic mountains.
• Block Mountains are Horsts and the lowered blocks of Block Mountains are called graben.
• Mountains are called storehouse of the water.
• An elevated flat land or flat topped table land is called Plateau.
• The height of a Plateau is measured above the 600m.
• Plains are large stretches of flat land which is generally till 600m.

Chapter 7 : Our Country India

• India has a vast geographical expanse as in North, it is bounded by Himalayas; in west by Arabian sea, Bay of Bengal in east and Indian Ocean in south.
• Area of India is about 3.28 million km². From North to South, it extends about 3200km. And, from east to west it extends about 2900km.
• Kashmir in North, Kanyakumari in South, Arunachal Pradesh in East and Rann of Kutch are the last point of the country.
• India is located at the Northern Hemisphere and Tropic of Cancer (23◦30’N) passes through half way of the country.
• India and Sri Lanka are separated by the Palk Strait.
• Neighboring countries of India are: Nepal, Bhutan, Pakistan, China, Afghanistan, Myanmar, Sri Lanka and Bangladesh.
• There are 28 States and 8 Union territories.
• Physical divisions of India includes every type of domains. For example: Himalayas, The Great Indian Desert, Indian Ocean, Deccan Plateau and Lakshadweep Island etc.

Chapter 8 : India Climate Vegetation and Wildlife

• The day to day changes of atmosphere is called weather. A change in weather for a long period of time is known as season.
• Average weather condition which is measured over many years is called climate.
• Usually there are four main seasons in India.
• Climate of a place is affected by the distance from the sea level. Altitude, location and relief.
• Forests are the natural habitat of the wildlife.
• Special programs like Van Mahotsav are done to spread awareness about reducing the cutting of trees.
• Tiger is National animal of India and Peacock is National Bird of India; and Gujrat is the home of Asiatic lions.
• Assam is the home of one horn Rhinoceros and elephants.
• The Great Indian Desert and the Rann of Kutch are the home of Camels.
• Himalayan Region are the home of wild goats, snow leopards, bear etc.
• More than 100 species of snakes are found in India including India cobra, Python, Kraits etc.
• To reduce the number of extinct species National Parks, Biosphere reserves and Sanctuaries are built to protect the different species of flora and fauna.
• The government of India has started project tiger and project elephant to protect their species.    

FAQ: