Text Book Back Questions and Answers - Chapter 1 The Universe and The Solar System Term 1 6th Social Geography Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

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Chapter 1 - The Universe and The Solar System - Term 1 - 6th Social Geography Guide Samacheer Kalvi Solutions- Text Book Back Questions and Answers

A. Fill in the blank
1. The Universe was formed after ___________ explosion.
2. _______ is the unit used to measure the distance between two celestial bodies.
3. ____________ is the centre of the solar system.
4. The word planet means _________
5. ______ planet has many natural satellites.
6. India's first ever mission to the moon is ____________ 
7. Earth is inclined by _________ degrees.
8. The Equator faces the Sun directly ______________ on and ___________ 
9. ______________ the time of Perihelion, the Earth is to the sun
10. The line which divides day and night on the Earth's surface is ___________ 

Answer:
1. Big Bang
2. Light year
3. Sun
4. Wanderer
5. Jupiter
6. Chandrayaan - I
7. $231 / 2$
8. 21st March and 23rd September
9. Closest
10. Terminator Line
B. Choose the bent answer

Question 1.
The movement of the Earth on its axis is called
(a) Revolution
(b) Seasons
(c) Rotation
(d) Circulation

Answer:
(c) Rotation

Question 2.
The Tropic of Capricorn faces the Sun directly on
(a) March 21
(b) June 21
(c) September 23
(d) December 22

Answer:
(d) December 22

Question 3.
The galaxy in which our solar system is found is
(a) Andromeda
(b) Magellanic clouds
(c) Milky Way
(d) Starburst

Answer:
(c) Milky Way

Question 4.
The only celestial body where man has successfully landed
(a) Mars
(b) Moon
(c) Mercury
(d) Venus

Answer:
(b) Moon

Question 5.
Which of the following planets can float on water?
(a) Jupiter
(b) Saturn
(c) Uranus
(d) Neptune

Answer:
(b) Saturn
C. Circle the odd one out
1. Venus, Jupiter, Neptune,
2. Saturn Sirius, Andromeda, Milky way, Magellanic clouds
3. Pluto, Eris, Ceres, Io
4. Comet, Asteroids, Meteorites, Dwarf planets
5. Rover, Orbiter, Aeroplane, Space shuttle

Answer:
1. Venus
2. Sirius
3. Io
4. Dwarf planets
5. Aeroptane
D. Match the following

1. Hottest Planet - a. Mars
2. Ringed Planet $-\mathrm{b}$. Neptune
3. Red Planet $-\mathrm{c}$. Venus
4. Somersaulting Planet $-d$. Saturn
5. Coldest Planet $-\mathrm{e}$. Uranus

Answer:
1. $-\mathrm{c}$
2. $-\mathrm{d}$
3. $-\mathrm{a}$
4. $-\mathrm{e}$
5. $-\mathrm{b}$
(I) Consider the following statement

Question 1.
1. Venus rotates from east to west.
2. The Tropic of Cancer faces the Sun on June 21.
3. Mars has rings around it.

Choose the correct answer using the codes given below.
(a) 1 and 2
(c) 1,2 and 3
(b) 2 and 3

(d) 2 only

Answer:
(a) 1 and 2
(II) Consider the following statements.

Question 1.
Statement Is Earth is called a watery planet, Statement II: The rotation of the Earth causes seasons. Which of the statement(s) is/are true?
(a) I is true; II is wrong
(b) I is wrong; II is true
(c) Both the statements are true
(d) Statements I and II are wrong.

Answer:
(a) I is true; II is wrong
F. Name the following
1. Cluster of stars. - Galaxy
2. The nearest galaxy to the solar system. - Magellanic clouds/Andromeda
3. The brightest planet. - Venus
4. The living sphere - Earth
5. The year which has 366 days. - Leap year
G. Answer in brief.

Question 1.
Name the inner planets.
Answer:
The inner planets are Mercury, Venus, Earth, and Mars.
Question 2.
Pluto is no longer a planet. Reason out.
Answer:

Unlike planets Pluto share its orbit with other planets.
Question 3.
What is perihelion?
Answer:
Perihelion is the Earth's closest position to the Sun.
Question 4.
How many times in a year would you find the Sun overhead if you lived on $20^{\circ} \mathrm{N}$ Latitude?

Answer:
2 times.
Question 5.
Which celestial body shares its orbit with others? Give an example, Answer:
1. The dwarf planets share their orbits with others.
2. The five dwarf planets of the solar system are Pluto, Ceres, Eris, Makemake and Haumea.
H. Give reasons.

Question 1.
Why is Uranus called the somersaulting planet?
Answer:

The axis of Uranus is tilted so much that, it appears to orbit the sun on its sides like a rolling ball. So uranus called the somersaulting planet.

Question 2.
The surface of the moon has many craters.
Answer:
The craters are formed due to the meteorites which fall on the moon's surface.
Question 3.
The velocity of Earth's rotation is zero at poles, Answer:
1. The Earth is a sphere.
2. It is widest at the equator, becoming increasingly narrow further toward to top and bottom.
3. The velocity of earth's rotation varies from $1670 \mathrm{~km} / \mathrm{hr}$ at equator and to $845 \mathrm{~km} / \mathrm{hr}$ at $60^{\circ} \mathrm{N}$ and $\mathrm{S}$ and zero at the poles.
I. Answer In detail.

Question 1.
Distinguish between inner and outer planets,

Answer:

Inner or Terrestrial Planets
1. Mercury, Venus, Earth, Mars.
2. They are comparatively smaller in size.
3. They are composed of rocks. The surface of the inner planets has mountains, volcanoes and craters.
4. None of the inner planets have rings orbiting them

Outer Planets or Jovian Planets, or Gaseous Giants
1. Jupiter, Saturn, Uranus, Neptune.
2. They are huge in size.
3. Most of them are made of gas.
4. All of the outer plants have rings orbiting them.

Question 2.
What are the effects of rotation and revolution?
Answer:
Rotation:
- The rotation of the earth causes day and night.
- As the earth is spherical in shape, only one half of it is illuminated by the sun at a time. The other half remains dark.
- The illuminated portion of the earth experiences day and the other part of the earth experiences night.

Revolution:
- The movement of the earth around the sun is called revolution.
- The revolution of the earth causes seasons.
- The revolution of the earth gives the impression that the sun is moving north and south of the equator.
- The equator faces the Sun directly on March 21 and September 23.
- During these two days the day and night are equal throughout the earth. These two days are called Equinoxes.
- On June 21, the Tropic of Cancer faces the sun. This is known as summer solstice. It is the longest day in the
- Northern Hemisphere and longest night in the Southern hemisphere.

Question 3.
Explain the characteristic! of the various spheres of the Earth.
Answer:
Earth is the most suitable planet to support life. It has three major components that we call as the 

realms of the Earth lithosphere, hydrosphere and atmosphere.
(i) Lithosphere : The word lithosphere is derived from the Greek word Lithos, which means rocky. The Lithosphere is the land on which we live.
(ii) Hydrosphere : The word Hydro means water in Greek. The hydrosphere consists of water bodies such as oceans, seas, rivers, lakes, ice caps on mountains and water vapour in the atmosphere.
(iii) Atmosphere : The word Atmo means air in Greek. Atmosphere is the envelope of air that surrounds the Earth. Different types of gases make up the atmosphere. The major gases are Nitrogen (78\%) and Oxygen (21\%).
(iv) Biosphere : The narrow belt of interaction among the lithosphere, the hydrosphere and the atmosphere, where life exists is known as Biosphere. Bio means life in Greek. It consists of distinct zones.
J. Picture Study,

Question 1.

Study the picture and answer the given questions,
a. Which is the closest planet to the Sun?
b. Which is the largest planet?
c. Which is the farthest planet from the Sun?
d. Which is the second smallest planet?

Answer:
a. Mercury
b, Jupiter
c, Neptune
d. Mars

Question 2.
Look at the picture and answer the questions given below,

(a) Identify the planet

Answer:
Uranus
(b) What is the colour of the planet?

Answer:
Green
(c) Why is it of this colour?

Answer:
It appears green due to the presence of methane
Student Activity
K. Solve the Puzzle Across

2. A dwarf planet.
3. Equal days and nights.
7. I am a gas found in the Sun.
8. I appear once in 76 years.

Down
1. I am the morning star.
2. India's first moon mission.
3. I have two natural satellites.
4. I am the farthest planet.
5. An imaginary line passing through
6. the centre of the Earth.

In-TextQuestion
HOTS:
Question 1.
Even though Mercury Is the nearest planet to the Sun, Venus Is the hottest one, Guess why?
Answer:
1. Venus is the hottest planet even though Mercury is the closest planet to the Sun.
2. The reason that Venus is hotter than Mercury is because it has an atmosphere made of Carbon dioxide.
3. It also has clouds of acid inside its atmosphere.
4. This is called Green House effect.

Question 2.
If you could put Saturn In a large enough ocean It would float. Guess why?
Answer:
1. Being less dense than water means that it would float on an ocean big enough to contain it.
2. Saturn is the only planet in the Solar System that is less dense than water.
3. Since Saturn is lighter that water, it can float on water.

Question 3.
Imagine you were on a space craft travelling at the speed of light from Earth, how long would It take to reach the Sun?
Answer:

1. Sunlight travels at the speed of light.
2. Photons emitted from the surface of the Sun need to travel across the vacuum of space to reach our eyes.
3. It takes sunlight to an average time of 8 minutes and 20 seconds to travel from the Sun to Earth.

Question 4.
We see only one side of the Moon always. Why?

Answer:
1. We can see only one side of the moon.
2. It is because the moon revolves around the Earth at the exact same speed as it rotates around its own axis.
3. So that the same side of the moon is constantly facing the surface of the Earth.
4. It takes 27 days and 8 hours for its one rotation.
5. If the moon did not rotate at all, we would see all of its sides.

Question 5.
Priya Is 12 years old. How many limes she would have revolved around the Sun?
Answer:

1. It takes the earth $3651 / 4$ days to complete one orbit around the sun.
2. It is the movement of the Earth around the Sun on its elliptical path.
3. priya is 12 years old. She would have revolved around the Sun 12 times.

Question 6.
If the Earth is not Inclined at $231 / 2^{\circ}$ angle, what would happen to the Earth?
Answer:
1. If the Earth weren't tilted on its axis, there would be no seasons and humanity would suffer.
2. An Earth without a tilt would get colder as you move away from the equator.
3. Humans would never survive the continuous winter of the high latitudes.
4. Fortunately, as things are, Earth 's tropical zones tend to have minimal temperature, daylength variability over the course of the year.

In-TextQuestion

Question 1.
Watch a show In the nearest planetarium,
(a) Share your experience In the class room,
(b) Make an album of Interesting facts about the Solar System.
(c) In the Solar System

Answer:
1. The hottest planet is not closest of the Sun.
2. The dwarf planet Pluto is smaller in diameter than the United States of America.
3. The edge of the Solar System is 1000 times farther away than Pluto.
4. Jupiter has the biggest Ocean of any planet.

Solar system profile:

Question 2.
Circle the leap years? 2000,2005, 2012,2014,2017, and 2020
Answer:
$2000,2012,2020$
A. Fill In the blanks :
1. Universe is also referred to as the ___ 
2. The study of the Universe is called ________
3. The sound travels at a speed of ________
4. In a galaxy, a huge cluster of stars are held by _________
5. The nearest galaxy to the Earth is ________
6 . The Roman word 'sol' means __
7. The Sun is made up of extremely hot gases like ___________ and ______________
8. There are ____________ planets in the solar system.
9. The curved path in which the planets move around the Sun is known as _____________
10. The four planets nearer to the Sun are called _______ Planets
11. Outer Planets are also called ________
12. The smallest planet is ____
13. The planet ___________ is called Earth's twin.
14. The living planet is ___________
15. The distance between the Sun and the Earth is about __________
16. The _________ is named after the Roman God of war.
17. ISRO has now become the ________ space agency to reach
18. The fastest spinning planet in the solar system is ______
19. Saturn has _______ natural satellites around it.
20. The specific gravity of Saturn is ______  
21. The astronomer William Herschel discovered _______ in 1781
22. The Planet _________ has striking blue and white features
23. The _______ planets are extremely cold and dark.
24. The Earth's satellite is _________
25. Asteroids are _________ the Planets.
26. The celestial object made up of a head and a tail is called a ___________

27. Shooting stars are nothing but ___________
28. The earth is ___________ in shape
29. The earth is __________ on its axis.
30. The rotation of the Earth _______ causes __________
31. In a leap year, there are ___________ days in the month of February.
32. When day and night are equal throughout the Earth, it is known as ____________
33. farthest position ofthe Earth from the Sun is known as ________
34. Summer Solstice is the longest day in ___________ Hemisphere
35. The longest day in __________ Hemisphere is called as Winter Solstice
36. The Greek word 'Lithos' means ________
37. The Greek word 'hydro' means __________
38. The ________ is made up of different types of gases.
39. In Biosphere, there are zones called ____________
40. Our solar system is a part of the ________ Galaxy.

Answer:
1. Cosmos
2. Cosmology
3. $330 \mathrm{~m} / \mathrm{sl}$
4. gravitational forcesl
5. Andromedal
6. Sun God
7. hydrogen and helium
8. eight
9. Orbit
10. Inner or Terrestriall
11. Jovian Planets or Gaseous Giantsl
12. Mercury
13. Venus
14. Earth

15. 150 million kilometer'
16. Mars
17. Fourth
18. Jupiter
19. 62
20. less than
21. Uranus
22. Neptune
23. Dwarf
24. Moon
25. Minor
26. Comet
27. Meteors
28. Spherical
29. rotates
30. Day,night
31. 29
32. Equinox
33. Aphelion
34. Northern
35. Southern
36. Rocky
37. Water
38. atmosphere
39. Eco system

40. Milky Way
B. Choose the correct answer

Question 1.
Galaxy means having a huge cluster of ____________
(a) Planets
(b) Asteroids
(c) Stars
(d) Meteors

Answer:
(e) Stars

Question 2.
The somersaulting planet is _______
(a) Venus
(b) Mars
(c) Neptune
(d) Uranus

Answer:
(d) Uranus

Question 3.
__________Is self-luminous and gives light on its own
(a) Sun
(b) Moon
(c) Star
(d) Earth

Answer:
(a) Sun

Question 4.
Halley comet will next appear in _________
(a) 2051
(b) 2041
(c) 2061
(d) 2031

Answer:
(c) 2061

Question 5.
The nearest planet is  ________
(a) Mercury
(b) Venus
(c) Neptune
(d) Jupiter

Answer:
(a) Mercury

Question 6.
The fifth-largest planet in the Solar system is ______
(a) Jupiter
(b) Mars
(c) Saturn
(d) Earth

Answer:
(d) Earth

Question 7.
lo, Europa, Ganymede, Callisto are a few large satellites of _____________
(a) Jupiter
(b) Mars
(c) Mercury
(d) Venus

Answer:
(a) Jupiter

Question 8.
The second-largest planet in the solar system is ____________
(a) Mars
(b) Star
(c) Earth
(d) Saturn

Answer:
(d) Saturn

Question 9.
Saturn's largest moon is _________
(a) Europa
(b) Callisto
(c) Titan
(d) Titania

Answer:
(c) Titan

Question 10.
Triton is the satellite of ___________
(a) Earth
(b) Juipeter
(c) Neptune
(d) Uranus

Answer:

(c) Neptune

Question 11.
Halley's comet is expected to appear in _________
(a) 2020
(b) 2014
(c) 2035
(d) 2020

Question 12.
Pick owt the leap year from the following:
(a) 2001
(b) 2014
(c) 2018
(d) 2020

Question 13.
Solid layer of rocks and soil is found in:
(a) Biosphere
(b) Lithosphere
(c) Hydrosphere
(d) Atmosphere
C. Find the odd one out

Question 1.
Mercury, Earth, Mars, Uranus

Answer:
Uranus, the other three rotate anti-clockwise.
Question 2.
Pluto, Ceres, Makemake, Titan.
Answer:
Titan,Titan is a moon. Other three are Dwarf planets.
Question 3.
Sol, Bio, Atmo, Hydro
Answer:
Sol, it a Roman word. Other three are Greek words.
Question 4.
Mars, Saturn, Mercury, Jupiter.
Answer:
Mercury, R doesn't have any moon. Other three have moons.
Question 5.
Europa, Ganymede, Pluto, Callisto.
Answer:
Pluto, $\mathrm{R}$ is a dwarf planet. Other three are satellites of Jupiter.
D. Match the following

Question 1.
1. Planets - (a) Jovian planet
2. Mercury - (b) Earth's Twin
3. Neptune - (c) Living planet
4. Venus - (d) Wanderer
5. Earth - (e) Innner planet

Answer:

1. $(1-\mathrm{d})$
2. $(2-\mathrm{e})$
3. $(3-a)$
4. $(4-b)$
5. $(5-c)$

Question 2.
1. Cosmos - (a) Self-luminous
2. Sun - (b) Axis tilted
3. Orbit - (c) Universe
4. Mercury - (d) Curved path
5. Uranus - (e) No natural satellite

Answer:
1. $(1-c)$
2. $(2-a)$
3. $(3-\mathrm{d})$
4. $(4-e)$
5. $(5-b)$

Question 3.
1. Summer Solstice - (a) 22nd December

2. Equinox - (b) Rocky
3. Winter Solstice - (c) 21 st June
4. Lithos - (d) Water
5. Hydro - (e) 21st March

Answer:
1. $(1-\mathrm{c})$
2. $(2-\mathrm{e})$
3. $(3-a)$
4. $(4-b)$
5. $(5-\mathrm{d})$
E. Consider the following statement:

Question 1.
1. Universe is referred to Cosmos.
2. The Sun is at the centre of the solar system.
3. Pluto is a dwarf planet.

Choose the correct answer using the codes given below:
(a) 1 and 2
(b) 2 and 3
(c) 1,2 and 3
(d) 1 only.

Answer:
(c) 1,2 and 3

Question 2.

1. Biosphere consists of Ecosystems.
2. Atmosphere consists of water bodies.
3. Lithosphere is the solid outer layer of the! Earth.

Choose the correct answer using the codes given below:
(a) 1 and 2
(b) 1 and 3
(c) 1,2 and 3
(d) 2 only.

Answer:
(b) 1 and 3

Question 3.
Statement I : Jupiter is the eighth planet from the Sun.
Statement II : Jupiter is the Gaseous Giant planet.
Which of the following statements is/are time?
(a) I is true, II is wrong
(b) I is wrong, II is true
(c) Both the statements are true
(d) Both the statements are wrong

Answer:
(b) 1 is wrong, II is true

Question 4.
Statement I : Summer Solstice is the longest day with Southern Hemisphere.
Statement II : Winter Solstice is the longest day in the Northern Hemisphere.
(a) $\mathrm{I}$ is true, $\mathrm{II}$ is wrong
(b) I is wrong, II is true
(c) Both the statements are true
(d) Both the statements are wrong

Answer:
(d) Both the statements are wrong!
F. Name the following

Question 1.
1. A massive explosion to bring the celestial bodies into existence.
2. The somersaulting plant.
3. The study of the Universe.
4. Outer Planets or Jovian Planets .
5. Morning Star.
6. Red Planet.
7. Fastest spinning Planet.
8. Its specific gravity in less than water.
9. This planet appears green.
10. It comesdose to the Earth every 76 years.
11. Shooting Star.
12. It is in spherical shape.
13. The spinning movement of the Earth.
14. 21st March and 23rd September.
15. This layer is made up of different types of gases.

Answer:
1. Big Bang
2. Uranus
3. Cosmology
4. Gaseous giants

5. Verms
6. Viars
7. Jupiter
8. Saturn
9. Uranus
10. Halley's Comet
11. Meteors
12. Earth
13. Rotation
14. Equinoxes
15. Atmosphere
G. Answer in a sentence or two

Question 1.
W hat does the universe consist of?
Answer:
The universe consists of billions of galaxies, stars, planets, comets, asteroids, meteors
Question 2.
Did the ancient Tamils know that the planets went around the Sun? It yes, then give example.
Answer:
Yes. In Tamil literature, Sirupanatruppadai, it is mentioned that the Sun is surrounded by planets.
Question 3.
What is a solar system?
b
1. The solar system is gravitationally bound system.

2. It comprises of the Sun, the eight planets, dwarf planets, satellites, comets, asteroids and meteors.

Question 4.
Name the eight planets.
Answer:
1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus and
8. Neptune are the planets.

Question 5.
Write a note on the venus.
Answer:
1. Venus rotates in the opposite direction to all other planets except Uranus.
2. It has no natural satellites.
3. It is often visible in the mornings and the evenings. So it is also known as Morning Star and the Evening Star.

Question 6.
Name the tw o natural satellites of Mars.
Answer:
Phobos and Deimos are the two natural satellites of Mars.
Question 7.
Name the four largest satellites of Jupiter.
Answer:
Io, Europa, Ganymede and Callisto are the four largest satellites of Jupiter.

Question 8.
Define satellites
Answer:
Satellites are celestial objects, which revolve around the planets.
Question 9.
Where do we find the Asteroids?
Answer:
1. Asteroids are small solid objects that move around the Sun.
2. They are found as a belt between the Mars and Jupiter.
3. They are too small to be called as planets

Question 10.
What is the Rotation?
Answer:
Rotation is the spinning movement of the Earth on its axis.
Question 11.
What is Revolution?
Answer:
Revolution is the movement of the Earth around the Sun on its elliptical path.
$\mathrm{H}$. Give reasons.

Question 1.
The eight planets revolve in their respective orbits.
Answer:
The eight planets revolve in their respective orbits because of the gravitational pull of the Sun.
Question 2.
Planet Mercury experiences extremes of temperature.
Answer:
Mercury does not have an atmosphere and so experiences extremes of temperature. Life is possible on the Earth.

Question 3.
Life is possible on Earth because of the presence of land, air and water.
Answer:
Mars appears red in colour.
Question 4.
Mars appears red in colour
Answer:
Mars appears red in colour due to presence of iron oxide on its surface.
Question 5.
Seasons are caused.
Answer:
The inclination of the Earth on its axis and its revolution around the Sun cause different seasons.
Question 6.
We think the sun is continuously moving north and south of the equator.

Answer:
The changing position of the Earth in its orbit during revolution gives this impression.
I. Answer In detail.

Question 1.
Distinguish between Mercury and Venus.
Mercury
1. Smallest and closest planet to the Sun.
2. Experiences extremes of temperature.
3. Airless and waterless planet.

Venus
1. Second planet from the Sun.
2. Rotates in opposite direction. Hottest planet.
3. Brightest planet.

Question 2.
Distinguish between Asteroids and Comets.
Answer:
Asteroids
1. Small solid objects moving around the Sun.
2. Found as a belt between Mars and Jupiter.
3. They are too small to be called planets.
4. They are also known as Minor Planets or Planetoids

Comets
1. A celestial object made up of a head and tail.
2. The head of a comet consists of solid particles held together by ice and the tail is made of gases.
3. Halley's comet comes Close to earth every 76 years.