Our Earth | Indian GK | School GK | GK Olympiad | General Knowledge MCQs with Answer

The Earth is our home. It is the planet where all living beings—humans, animals, plants, and microorganisms—live together. Earth is unique because it is the only planet in the solar system known to have life. It gives us air to breathe, water to drink, land to live on, and food to eat. Understanding our Earth helps us to respect nature and take care of our environment.

Position of Earth in the Solar System

The Earth is the third planet from the Sun. The solar system has eight planets, and Earth is one of them. It is called a terrestrial planet because it is made of rock and metal, unlike gas giants like Jupiter and Saturn.

Earth is about 150 million kilometers away from the Sun. This distance is perfect for life because it is neither too hot nor too cold. That is why Earth is called the Goldilocks Planet.

Shape and Size of Earth

The Earth is round, but it is not a perfect sphere. Its shape is called an oblate spheroid—slightly flattened at the poles and bulging at the equator.

• Diameter: About 12,742 kilometers.
• Surface: Around 71% of Earth is covered with water, and 29% is land.
• Atmosphere: Earth is surrounded by layers of gases, which protect us and support life.

Layers of the Earth

Earth is made up of different layers.

1. Crust – The outer layer. It is made of rocks and soil. Mountains, oceans, and land are part of the crust.
2. Mantle – Found below the crust. It is made of hot rocks and magma.
3. Outer Core – A liquid layer made of iron and nickel. It is responsible for Earth’s magnetic field.
4. Inner Core – A solid metallic ball made of iron at the center of the Earth. It is the hottest part of Earth.

Movements of the Earth

Earth is always moving. It has two main movements:

1. Rotation – Earth spins on its axis once every 24 hours. This causes day and night.
2. Revolution – Earth moves around the Sun once every 365 days (one year). This causes seasons—summer, winter, autumn, and spring.

These movements affect life on Earth by giving us time, weather, and seasons.

Earth’s Atmosphere

The atmosphere is a blanket of gases around Earth. It protects us from harmful radiation and helps maintain temperature.

The main gases are:

• Nitrogen (78%)
• Oxygen (21%)
• Carbon dioxide, argon, and others (1%)

The atmosphere has five layers:

1. Troposphere – Closest to Earth, where weather happens.
2. Stratosphere – Contains the ozone layer that protects us from harmful UV rays.
3. Mesosphere – Destroys meteors that fall towards Earth.
4. Thermosphere – Where satellites and the aurora (northern lights) are found.
5. Exosphere – The outermost layer, merging into space.

Water on Earth

Earth is called the Blue Planet because most of its surface is covered with water.

• Oceans and Seas – 97% of Earth’s water is salty.
• Freshwater – Only 3% of water is freshwater, found in rivers, lakes, and glaciers.

Water is essential for all life. Without it, Earth would not have living beings.

Landforms of Earth

The land part of Earth has different shapes, called landforms.

• Mountains – High, steep areas like the Himalayas.
• Plains – Flat areas good for farming, like the Gangetic Plains.
• Plateaus – Elevated flatlands, like the Deccan Plateau.
• Deserts – Dry areas with little rainfall, like the Thar Desert.
• Islands – Land surrounded by water, like the Andaman Islands.

Life on Earth

Earth is the only planet with life because of:

• Air – Oxygen for breathing.
• Water – Essential for all living beings.
• Soil – Helps plants grow.
• Climate – Balanced temperature for survival.

Plants, animals, and humans form a system called the biosphere, where all living things interact with the environment.

Earth’s Natural Resources

Earth provides us with many resources:

• Soil for farming.
• Water for drinking and irrigation.
• Minerals like iron, coal, gold, and copper.
• Forests for wood, medicines, and oxygen.
• Fossil fuels like oil and gas for energy.

We must use these resources carefully, otherwise they will get exhausted.

Protection of Earth

Earth is facing many problems like pollution, deforestation, and climate change. If we do not take care of it, life will become difficult.

Ways to protect Earth:

1. Plant more trees.
2. Save water and electricity.
3. Reduce, reuse, and recycle waste.
4. Use clean energy like solar and wind power.
5. Avoid cutting forests.

Saving Earth is our duty because it is our only home.

Interesting Facts About Earth

• Earth is about 4.5 billion years old.
• It is the fifth largest planet in the solar system.
• Earth’s gravity keeps us and the atmosphere in place.
• The highest point on Earth is Mount Everest (8,849 m).
• The deepest point is the Mariana Trench in the Pacific Ocean.
• Earth is sometimes called the Living Planet because of the biosphere.

Conclusion

Earth is truly a special planet. It gives us everything we need to survive—air, water, land, and life. From its layers deep inside to the mountains and oceans outside, Earth is full of wonders. Its rotation and revolution give us days, nights, and seasons.

For students, learning about Earth is important because it helps us understand the environment and our responsibility to protect it. We must always remember—there is only one Earth, and we must take care of it.

MCQs – Our Earth

1. Earth is the ______ planet from the Sun.
   a) First
   b) Second
   c) Third
   d) Fourth
2. Earth is described as a ______ planet.
   a) Gas
   b) Rocky, terrestrial
   c) Ice
   d) Fire
3. The only astronomical object known to harbour and support life is:
   a) Moon
   b) Mars
   c) Earth
   d) Venus
4. How many main layers is the Earth composed of?
   a) 2
   b) 3
   c) Several
   d) 10
5. Which is the only liquid layer of the Earth?
   a) Inner core
   b) Crust
   c) Mantle
   d) Outer core
6. The outer core is mainly made of:
   a) Gold and Silver
   b) Silicon and Aluminium
   c) Iron and Nickel
   d) Copper and Zinc
7. Which layer is responsible for Earth’s magnetic field?
   a) Mantle
   b) Inner core
   c) Outer core
   d) Crust
8. The hottest part of Earth is:
   a) Mantle
   b) Inner core
   c) Outer core
   d) Crust
9. What is the inner core made of?
   a) Iron only
   b) Gold
   c) Solid metallic iron
   d) Rocks
10. Earth’s hard outer layer is called:
    a) Mantle
    b) Crust
    c) Asthenosphere
    d) Outer core
11. The crust is made of:
    a) Water
    b) Rocks
    c) Gas
    d) Metals only
12. Which layer lies below the lithosphere?
    a) Asthenosphere
    b) Inner core
    c) Mantle
    d) Crust
13. Which layer of solid rock has so much pressure and heat that rocks can flow like liquid?
    a) Mantle
    b) Inner core
    c) Asthenosphere
    d) Lithosphere
14. Which layer lies between Earth’s core and crust?
    a) Inner core
    b) Outer core
    c) Mantle
    d) Lithosphere
15. The mantle is made of rocks containing:
    a) Silicon, iron, magnesium, aluminium, oxygen
    b) Gold, copper, zinc
    c) Ice and water
    d) Carbon and nitrogen
16. Which layer lies between the crust and uppermost mantle?
    a) Lithosphere
    b) Asthenosphere
    c) Inner core
    d) Outer core
17. The lithosphere is subdivided into:
    a) Rock particles
    b) Water masses
    c) Tectonic plates
    d) Layers of air
18. The crust and uppermost mantle together form the:
    a) Asthenosphere
    b) Lithosphere
    c) Inner core
    d) Mantle
19. Which layer is a solid metallic ball at the centre of the Earth?
    a) Outer core
    b) Inner core
    c) Mantle
    d) Crust
20. Which layer is described as “super-heated and dense”?
    a) Lithosphere
    b) Mantle
    c) Core
    d) Crust

Answer Key

1. c) Third
2. b) Rocky, terrestrial
3. c) Earth
4. c) Several
5. d) Outer core
6. c) Iron and Nickel
7. c) Outer core
8. b) Inner core
9. c) Solid metallic iron
10. b) Crust
11. b) Rocks
12. a) Asthenosphere
13. c) Asthenosphere
14. c) Mantle
15. a) Silicon, iron, magnesium, aluminium, oxygen
16. b) Asthenosphere
17. c) Tectonic plates
18. b) Lithosphere
19. b) Inner core
20. c) Core

Some Important Links