[Earth is the third planet from the Sun and the only known planet in the Solar System that supports life. It is often called the “Blue Planet” formed around 4.5 billion years ago from a cloud of gas and dust called the solar nebula. It has a spherical shape (geoid) and rotates on its axis while also revolving around the Sun. The Earth has a layered structure: Crust, Mantle, Core. Earth is surrounded by an atmosphere made mainly of nitrogen (78%) and oxygen (21%), which protects life from harmful solar radiation and helps maintain temperature. Two main movements of Earth are: Rotation → causes day and night (about 24 hours); Revolution → causes seasons (about 365¼ days). Earth is unique because it has liquid water, suitable temperature, and a protective atmosphere, making it the only known planet capable of supporting life]
1Q. Which planet is known as the “Blue Planet” in the Solar System?
Ans: Earth
2Q. Which is the only known planet to support life?
Ans: Earth
3Q. What is the natural satellite of Earth?
Ans: Moon
4Q. Which force keeps Earth in orbit around the Sun?
Ans: Gravity
5Q. What is the shape of Earth called?
Ans: Geoid
6Q. Which layer of Earth lies between the crust and the core?
Ans: Mantle
7Q. Which is the hottest layer inside Earth?
Ans: Inner Core
8Q. What is the approximate age of Earth?
Ans: About 4.5 billion years
9Q. Which movement of Earth causes day and night?
Ans: Rotation
10Q. Which movement of Earth causes seasons?
Ans: Revolution
11Q. How much time does Earth take to complete one rotation?
Ans: About 24 hours
12Q. How much time does Earth take to revolve around the Sun?
Ans: About 365¼ days
13Q. What is the imaginary line passing through Earth’s poles called?
Ans: Axis
14Q. At what angle is Earth tilted on its axis?
Ans: 23½°
15Q. What is the path of Earth around the Sun called?
Ans: Orbit
16Q. Which phenomenon occurs due to Earth’s tilted axis?
Ans: Seasons
17Q. What is the closest point of Earth to the Sun called?
Ans: Perihelion
18Q. What is the farthest point of Earth from the Sun called?
Ans: Aphelion
19Q. On which date is Earth nearest to the Sun?
Ans: Around 3 January
20Q. On which date is Earth farthest from the Sun?
Ans: Around 4 July
21Q. Which imaginary line divides Earth into Northern and Southern Hemispheres?
Ans: Equator
22Q. What are the lines running east-west on Earth called?
Ans: Latitudes
23Q. What are the lines running north-south on Earth called?
Ans: Longitudes
24Q. Which longitude is known as the Prime Meridian?
Ans: 0° Longitude
25Q. Which latitude is known as the Tropic of Cancer?
Ans: 23½° North
26Q. Which latitude is known as the Tropic of Capricorn?
Ans: 23½° South
27Q. Which latitude is called the Arctic Circle?
Ans: 66½° North
28Q. Which latitude is called the Antarctic Circle?
Ans: 66½° South
29Q. Which layer of Earth contains the ozone layer?
Ans: Stratosphere
30Q. Which is the lowest layer of Earth’s atmosphere?
Ans: Troposphere
31Q. In which layer do weather changes occur?
Ans: Troposphere
32Q. Which gas is most abundant in Earth’s atmosphere?
Ans: Nitrogen
33Q. Which gas supports life on Earth?
Ans: Oxygen
34Q. Which gas protects Earth from harmful ultraviolet rays?
Ans: Ozone
35Q. Which planet has conditions most similar to Earth?
Ans: Venus
36Q. Which planet is called Earth’s twin?
Ans: Venus
37Q. Which planet is larger than Earth and famous for the Great Red Spot?
Ans: Jupiter
38Q. Which is the third planet from the Sun?
Ans: Earth
39Q. Which celestial event occurs when Earth comes between the Sun and Moon?
Ans: Lunar Eclipse
40Q. Which celestial event occurs when the Moon comes between Earth and the Sun?
Ans: Solar Eclipse
41Q. What is the speed of Earth’s rotation at the equator?
Ans: About 1670 km/h
42Q. What causes tides on Earth?
Ans: Gravitational pull of the Moon and Sun
43Q. Which planet has liquid water on its surface?
Ans: Earth
44Q. What is the outermost solid layer of Earth called?
Ans: Crust
45Q. Which instrument measures earthquakes on Earth?
Ans: Seismograph
46Q. What is the boundary between Earth’s crust and mantle called?
Ans: Mohorovičić Discontinuity (Moho)
47Q. Which layer of Earth is made mainly of molten iron and nickel?
Ans: Outer Core
48Q. What protects Earth from solar winds?
Ans: Magnetic Field
49Q. What is the study of Earth called?
Ans: Geology
50Q. Which planet in the Solar System has the highest density?
Ans: Earth
51Q. Which scientist first explained that Earth revolves around the Sun?
Ans: Nicolaus Copernicus
52Q. Which proof supports Earth’s rotation on its axis?
Ans: Foucault Pendulum
53Q. Which proof supports Earth’s revolution around the Sun?
Ans: Stellar Aberration
54Q. What is the velocity of Earth’s revolution around the Sun?
Ans: About 29.8 km/s
55Q. Which imaginary circle receives the vertical rays of the Sun on 21 June?
Ans: Tropic of Cancer
56Q. Which imaginary circle receives the vertical rays of the Sun on 22 December?
Ans: Tropic of Capricorn
57Q. During which equinox are day and night equal throughout Earth?
Ans: 21 March and 23 September
58Q. Which force causes Earth to bulge at the equator?
Ans: Centrifugal Force
59Q. Why is Earth slightly flattened at the poles?
Ans: Due to rotation
60Q. What is the angular speed of Earth’s rotation?
Ans: 15° per hour
61Q. Which longitude determines the International Date Line?
Ans: 180° Longitude
62Q. Which country is nearly divided into two dates by the International Date Line?
Ans: Russia
63Q. Which atmospheric layer reflects radio waves back to Earth?
Ans: Ionosphere
64Q. Which atmospheric layer is nearest to outer space?
Ans: Exosphere
65Q. Which layer of Earth’s atmosphere contains electrically charged particles?
Ans: Thermosphere
66Q. What is the average distance between Earth and the Sun?
Ans: About 149.6 million km
67Q. Which term describes Earth’s daily spinning movement?
Ans: Diurnal Motion
68Q. Which waves cannot travel through liquid layers inside Earth?
Ans: S-Waves
69Q. Which date marks the Summer Solstice in the Northern Hemisphere?
Ans: 21 June
70Q. Which date marks the Winter Solstice in the Northern Hemisphere?
Ans: 22 December
71Q. Which branch of science studies Earth’s atmosphere and weather?
Ans: Meteorology
72Q. What is 0° longitude called?
Ans: Prime Meridian
73Q. What is the speed of light from the Sun to Earth?
Ans: About 8 minutes 20 seconds
74Q. Which planet has the strongest magnetic field after Jupiter?
Ans: Earth
75Q. Which geophysical phenomenon proves Earth’s internal heat?
Ans: Volcanism
76Q. Which discontinuity separates Earth’s mantle and core?
Ans: Gutenberg Discontinuity
77Q. Which layer of Earth is responsible for plate tectonics?
Ans: Lithosphere
78Q. Which movement of tectonic plates causes earthquakes?
Ans: Plate Tectonics
79Q. Which zone around Earth traps charged particles from the Sun?
Ans: Van Allen Radiation Belt
80Q. What is 180° longitude called?
Ans: International Date Line