General Knowledge Questions on our Planet Earth with MCQs

In this article, we will solve some General Knowledge Questions on our Planet Earth:-

1. What is the Earth mostly covered by?

A) Desert
B) Water
C) Forest
D) Ice

Answer: B) Water

Explanation: About 71% of Earth’s surface is covered by water, mostly in the form of oceans.Only, around 30 percent is land.

2. Which layer of Earth is solid and rocky?

A) Inner Core
B) Mantle
C) Crust
D) Outer Core

Answer: C) Crust

Explanation: The Earth’s crust is the solid, rocky outer layer. The mantle below is semi-fluid, and the core is made up of solid and liquid metal.

3. What is Earth’s atmosphere mostly made of?

A) Carbon Dioxide
B) Nitrogen
C) Oxygen
D) Methane

Answer: B) Nitrogen

Explanation: The Earth’s atmosphere is about 78% nitrogen and 21% oxygen, with trace amounts of other gases like carbon dioxide,ozone etc.

4. How long does it take for Earth to complete one rotation on its axis?

A) 12 hours
B) 24 hours
C) 48 hours
D) 36 hours

Answer: B) 24 hours

Explanation: Earth completes one full rotation about its axis roughly every 24 hours, which is why we have day and night and one revolution takes around 365 days to complete .

5. What is the largest ocean on Earth?

A) Atlantic Ocean
B) Indian Ocean
C) Arctic Ocean
D) Pacific Ocean

Answer: D) Pacific Ocean

Explanation: The Pacific Ocean is the largest and deepest of Earth’s oceanic divisions, covering more area than all of Earth’s landmass combined.

6. Which is the largest continent on Earth?

A) Africa
B) Asia
C) North America
D) Europe

Answer: B) Asia

Explanation: Asia is Earth’s largest continent, both in terms of land area and population.Area of Asia is around 44.6 million square kilometres , second is africa .The area of Africa continent isaround 30 million square kilometres .Are of North America is 25 million square kilometres . The Area of Europe is around 10 million square kilometres .

7. What is the hottest layer of the Earth?

A) Crust
B) Mantle
C) Inner Core
D) Outer Core

Answer: C) Inner Core

Explanation: The inner core is the hottest layer of Earth, with temperatures estimated to be around 5,000 to 6,000°C (9,032 to 10,832°F).

8. How old is Earth estimated to be?

A) 1.5 billion years
B) 4.5 billion years
C) 2.5 billion years
D) 6.5 billion years

Answer: B) 4.5 billion years

Explanation: According to current scientific estimates, Earth is about 4.5 billion years old, based on evidence from radiometric age-dating of meteorite samples and Earth rocks.

9. What causes tides on Earth?

A) The Sun
B) The Moon
C) Wind
D) Earth’s rotation

Answer: B) The Moon

Explanation: Tides are mainly caused by the Moon’s gravitational pull on Earth’s oceans. The Sun also has an effect, but it’s about half as strong as the Moon’s influence.

10. What percentage of Earth’s water is fresh water?

A) 10%
B) 2.5%
C) 50%
D) 30%

Answer: B) 2.5%

Explanation: Only about 2.5% of Earth’s water is fresh water, and most of that is trapped in glaciers or underground. Very little is in rivers and lakes.

11. What is the main gas responsible for the greenhouse effect?

A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Methane

Answer: C) Carbon Dioxide

Explanation: Carbon dioxide is the primary gas responsible for the greenhouse effect, which traps heat in the Earth’s atmosphere. While other gases like methane also contribute, carbon dioxide has the most significant impact.

12. What is the largest desert on Earth?

A) Sahara
B) Arabian
C) Atacama
D) Antarctic

Answer: D) Antarctic

Explanation: While many people think of the Sahara as the largest desert, technically, the Antarctic desert holds this title. Deserts are defined by low precipitation, not necessarily heat, and Antarctica fits this criteria.

13. What is the primary source of Earth’s energy?

A) The Moon
B) Geothermal heat
C) The Sun
D) Fossil fuels

Answer: C) The Sun

Explanation: The Sun is Earth’s primary source of energy. It provides the heat and light that sustain life on our planet, drive weather patterns, and power natural processes.

14. Which layer of Earth’s atmosphere is closest to the surface?

A) Stratosphere
B) Troposphere
C) Mesosphere
D) Exosphere

Answer: B) Troposphere

Explanation: The troposphere is the layer of Earth’s atmosphere that is closest to the surface. It extends up to about 8 to 15 kilometers (5 to 9 miles) and contains most of the atmosphere’s mass.Every Weather Phenomena Occurs in this layer only .

15. What is the Earth’s diameter?

A) 8,000 miles
B) 12,742 kilometers
C) 40,000 kilometers
D) 5,000 miles

Answer: B) 12,742 kilometers

Explanation: The Earth’s diameter is approximately 12,742 kilometers (7,918 miles). This measurement can vary slightly due to the Earth not being a perfect sphere but an oblate spheroid.

16. Which planet is known as Earth’s “twin”?

A) Mars
B) Venus
C) Jupiter
D) Saturn

Answer: B) Venus

Explanation: Venus is often called Earth’s “twin” because it is similar in size, composition, and proximity to the Sun. However, its atmosphere and climate are vastly different from Earth’s.

17. What is the name of the boundary that separates the Earth’s crust and mantle?

A) Moho
B) Core-mantle boundary
C) Tropopause
D) Mesopause

Answer: A) Moho

Explanation: The boundary that separates the Earth’s crust from its mantle is called the Mohorovičić discontinuity, commonly referred to as the Moho.

18. What percentage of Earth’s surface is covered by land?

A) 29%
B) 50%
C) 71%
D) 15%

Answer: A) 29%

Explanation: About 29% of Earth’s surface is covered by land, while the rest is covered by water.

19. Which is the highest mountain on Earth?

A) Mount McKinley
B) Mount Kilimanjaro
C) Mount Everest
D) K2

Answer: C) Mount Everest

Explanation: Mount Everest is the highest mountain on Earth, with a peak that rises to an elevation of 8,848 meters (29,029 feet) above sea level.It is situated in Nepal on border with China .

20. Which gas is most abundant in Earth’s crust?

A) Oxygen
B) Silicon
C) Aluminum
D) Iron

Answer: A) Oxygen

Explanation: Oxygen is the most abundant element in Earth’s crust, making up about 46.6% of its weight. It’s primarily found in the form of oxides and in minerals.

21. What is the longest river on Earth?

A) Amazon
B) Nile
C) Yangtze
D) Mississippi

Answer: A) Amazon

Explanation: The Amazon River, located in South America, is generally considered the longest river on Earth, especially when one includes some of its tributaries in the Andes.

22. How many time zones does Earth have?

A) 12
B) 24
C) 36
D) 48

Answer: B) 24

Explanation: Earth has 24 time zones, which correspond roughly to 15 degrees of longitude each, making a full circle of 360 degrees around the Earth.

23. What is the Earth’s average distance from the Sun?

A) 149.6 million kilometers
B) 92.96 million miles
C) 10 million miles
D) Both A and B

Answer: D) Both A and B

Explanation: The Earth’s average distance from the Sun is about 149.6 million kilometers or 92.96 million miles. This distance is known as an astronomical unit (AU).

24. What causes Earth’s seasons?

A) Distance from the Sun
B) Earth’s rotation
C) Earth’s axial tilt
D) Moon’s gravitational pull

Answer: C) Earth’s axial tilt

Explanation: Earth’s seasons are caused by the tilt of its axis, not its distance from the Sun. The axial tilt causes different parts of the Earth to receive varying amounts of sunlight at different times of the year.

25. What is the Earth’s axial tilt?

A) 23.5 degrees
B) 15 degrees
C) 30 degrees
D) 10 degrees

Answer: A) 23.5 degrees

Explanation: The Earth’s axis is tilted from perpendicular to the plane of the ecliptic by about 23.5 degrees. This tilt is responsible for the change of seasons on Earth.

26. Which ocean is the smallest?

A) Atlantic
B) Indian
C) Arctic
D) Southern

Answer: C) Arctic

Explanation: The Arctic Ocean is the smallest and shallowest of the world’s five major oceans.

27. What type of rock is the Earth’s crust mostly made of?

A) Igneous
B) Sedimentary
C) Metamorphic
D) All of the above

Answer: A) Igneous

Explanation: The Earth’s crust is primarily made up of igneous rock. Igneous rocks form from the solidification and cooling of magma.

28. Which gas forms the ozone layer?

A) Oxygen
B) Carbon Dioxide
C) Ozone
D) Methane

Answer: C) Ozone

Explanation: The ozone layer is formed by ozone gas. It protects life on Earth by absorbing the majority of the sun’s harmful ultraviolet radiation.

29. What is the deepest part of Earth’s oceans?

A) Puerto Rico Trench
B) Mariana Trench
C) Tonga Trench
D) Sunda Trench

Answer: B) Mariana Trench

Explanation: The Mariana Trench is the deepest part of Earth’s oceans, with a maximum known depth of about 36,070 feet (10,984 meters).

30. What phenomenon causes the Northern and Southern Lights?

A) Reflection of the moon
B) Sunspots
C) Interaction between solar winds and Earth’s magnetic field
D) Light pollution

Answer: C) Interaction between solar winds and Earth’s magnetic field

Explanation: The Northern and Southern Lights, also known as Aurora Borealis and Aurora Australis, are caused by the interaction between solar winds and Earth’s magnetic field.

31. What is the driest place on Earth?

A) Sahara Desert
B) Atacama Desert
C) Death Valley
D) Antarctica

Answer: B) Atacama Desert

Explanation: The Atacama Desert in Chile is the driest place on Earth. Some weather stations in the desert have received little to no rainfall for hundreds of years.

32. What type of natural disaster is measured by the Richter scale?

A) Hurricanes
B) Earthquakes
C) Tornadoes
D) Volcanic eruptions

Answer: B) Earthquakes

Explanation: Earthquakes are measured by the Richter scale. The scale goes from 0 to 10, with each whole number increase indicating tenfold amplitude of seismic waves and roughly 31.6 times more energy release.

33. What is the primary reason for soil erosion?

A) Water
B) Wind
C) Human activity
D) All of the above

Answer: D) All of the above

Explanation: Soil erosion can be caused by water, wind, and human activity. While natural forces like water and wind contribute, human activities such as deforestation and poor land use intensify the process.

34. What are Earth’s polar regions covered with?

A) Sand
B) Ice
C) Forest
D) Grassland

Answer: B) Ice

Explanation: Earth’s polar regions are covered with ice. The Arctic to the north has mainly sea ice, while Antarctica to the south is a continent covered in ice sheets.

35. What is the second most abundant element in Earth’s crust?