These DAV Class 6 SST Book Solutions and DAV Class 6 SST Chapter 1 Question Answer – The Planet Earth and the Solar System are thoughtfully prepared by experienced teachers.
DAV Class 6 SST Ch 1 Question Answer – The Planet Earth and the Solar System
DAV Public School Class 6 SST Chapter 1 Question Answer – The Planet Earth and the Solar System
Something To Know
A. Tick (✓) the correct option.
Question 1.
What do we call a huge cluster of billions of stars?
(a) asteroids
(b) meteors
(c) galaxy
(d) universe
Answer:
(c) galaxy
Question 2.
Which one of the following is the hottest planet?
(a) Mercury
(b) Venus
(c) Mars
(d) Jupiter
Answer:
(b) Venus
Question 3.
Which is the most distant planet from the Sun?
(a) Uranus
(b) Neptune
(c) Saturn
(d) Jupiter
Answer:
(b) Neptune
Question 4.
The planet which does not have any satellite is
(a) Venus
(b) Mars
(c) Neptune
(d) Earth
Answer:
(a) Venus
Question 5.
Which planet has two satellites?
(a) Mercury
(b) Venus
(c) Earth
(d) Mars
Answer:
(d) Mars
B. Fill in the blanks.
1. The vast limitless space which includes all celestial bodies is called ……………
2. The distance between celestial bodies is measured in a unit called ……………
3. ………….. always indicates the north direction.
4. All the planets of our solar system revolve round the Sun in their fixed paths called ……………
5. …………… is the third nearest planet to the Sun.
Answer:
1. universe
2. light year
3. Pole Star
4. orbits
5. Earth
C. Match the following:
| 1. Great Bear | (a) Nebula |
| 2. Head of solar system | (b) Mars |
| 3. A giant cloud of gases and dust | (c) Sun |
| 4. Shape of the earth | (d) Constellation |
| 5. Red Planet | (e) Spherical |
Answer:
| 1. Great Bear | (d) Constellation |
| 2. Head of solar system | (c) Sun |
| 3. A giant cloud of gases and dust | (a) Nebula |
| 4. Shape of the earth | (e) Spherical |
| 5. Red Planet | (b) Mars |
D. Answer the following questions in brief.
Question 1.
What are celestial bodies?
Answer:
The sun, the stars, the moon, the planets and other objects are all heavenly or celestial bodies.
Question 2.
Why do stars look very small in the sky?
Answer:
Stars look very small in the sky because they are very far from the earth.
Question 3.
What is ‘Saptarishi Mandal?
Answer:
Ursa Major, also called the Great Bear, is a constellation of several stars. It appears in the northern sky. In India, the seven stars called Saptarishi Mandal, is a part of Great Bear.
Question 4.
Name the planets which are gaseous bodies.
Answer:
Jupiter, Saturn, Uranus.
Question 5.
Which planet is the closest to Neptune?
Answer:
Uranus.
E. Answer the following questions.
Question 1.
Describe the formation of solar system.
Answer:
The solar system is the system which is constituted by the sun and its companion celestial bodies. The eight planets, their companion satellites, asteroids, meteors and comets are the members of the solar system. They all revolve around the sun on their fixed baths called orbits. Some scientists believe that a giant cloud of gases and dust called the Nebula appeared moving in the space about 4.6 billions of years ago.
It cooled and gained very fast rotation. The eight balls of gases of different sizes were separated from the Nebula. The remaining central mass of the Nebula changed into a star known as the sun. The other eight balls changed into planets. It is believed that the satellites were formed when small balls of gases separated from the central mass were attracted by their companion planets.
Question 2.
State three features which make the earth a unique planet.
Answer:
Three features which make the earth a unique planet are –
The earth receives moderate heat and light from the sun. This much quantity of heat and light is just sufficient to evolve and sustain all forms of life on the earth’s surface. Other planets are either very hot or very cold.
About two-third of earth’s area is covered with water. Needless to say that water is essential for human beings, animals and plants.
The earth has an envelope of air or atmosphere around it. It contains gases like oxygen, nitrogen, carbon dioxide, etc. All animals including human beings inhale oxygen for their survival. All the plants need carbon dioxide for their growth. Nitrogen is equally important for the plants arid animals.
Question 3.
Mention three main characteristics of asteroids
Answer:
Three main characteristics of asteroids:
- They are small planetary bodies which revolve around the sun.
- They lie in a gap of about 550 million kilometres between the mbits oi the Mars and the Jupiter.
- They are considered to be die fragments or an exploded planet.
Question 4.
Give a brief description of the phases of the Moon with the help of a diagram.
Answer:
The position of the moon in rotation to the sun changes everyday. When the illuminated side of lire moon is fully hidden from our view, it. is called the new moon. The visible portion goes on increasing gradually day by day alter the new moon day. At hist the moon appears in crescent shape. On 8th day, half portion of the muon comes in our view. The full moon
becomes visible after 15 days when j half of its revolution is completed, The day when the moon is completely | visible to us, is the full moon day. After this day, the decline of the moon’s illuminated part starts. The illuminated part slowly disappears and the moon again comes to the position of new moon. The phases of the moon are used to determine the lunar dates and to fix the duration of lunar months in India and Arab countries.
Question 5.
Write a short note on the other celestial bodies (asteroids, meteoroids and comets) in the solar system.
Answer:
Asteroids, meteors and comets are also celestial bodies which revolve around the sun.
1. Asteroids lie in a gap of about 550 million kilometres between the orbits of the Mars and the Jupiter. They are considered to be the fragments of an exploded planet. The largest asteroid is called cres.
2. Meteors are very small planetary masses which often enter earth’s atmosphere and get burnt due to friction. They appear as bright objects and are called shooting stars. The scientists believe that some asteroids often collide with each other and break into small pieces, while revolving in its paths. A few meteors of large size do not get fully burnt. Parts of them fall on the surface of the earth called meteorites.
3. Comets are the small bodies with a head and long luminous tail. They are made up of dust and frozen gases. They appear in the sky after a long period.
Value-Based Question
Indian Space Research Organisation (SRO) was established in 1969. It was the same year when humans set foot on the moon for the first time. ISRO launched Chandrayaan-1 on October 22, 2008 from Sriharikota. It showed India’s ability to do meaningful science at low cost, its leadership in a cooperative space venture and the capacity to develop essential technology’ within stipulated time. With this success, India became the fifth country to put a spacecraft into an orbit around the moon after the United States, Soviet Russia, Japan and China.
1. What is meant by ‘meaningful science?
2. Mention any two inventions to distinguish between ‘science’ and ‘meaningful science’.
3. Explain the values and life skills -which helped India to attain success in space.
Answer:
1. Meaningful science refers to meaningful scientific experiments or works. For example, in 1969 India Space Research Organisation (ISRO) -was established, and in the same year humans set foot on the moon for the first time. It showed India’s ability to do meaningful science at low cost.
2. S. Breschi and F. Lissoni.
3. India’s success in space is a subject of pride for the country’ as it puts Indians on the scientific world stage along with Americans, Russians and others. The second is more relevant to India’s ability to enhance its development for the benefit of its own people.
Scientific exploration including telecommunications, weather monitoring, navigation, etc, serves to provide a 21st century- infrastructure to stimulate economic growth, and provide educational and other services in technical disciplines that will aid the improvement and security of the country.
Map Skill
On the outline map of India, show the location of Indian space research centres.
Answer:
Something To Do
Question 1.
Prepare a model (working or static) of the Solar System.
Answer:
Do yourself.
Question 2.
When was Mars Orbiter Mission (MOM) launched by India? What are its achievements and why it is so important for us?
Answer:
Mars Orbiter Mission (MOM) was launched in October 2013 by India. The success of this mission represents a milestone in the country’s space programe. With these achievements, India joins a club of deep space explorers such as the US, Russia and Europe, all have reached Mars. Also it is so important for us as our country became the first single nation to reach the Red Planet and enter Orbit at its first round. We feel proud as it puts us on the scientific world stage alongwith Americans, Russians and others. The other one is more relevant as it proves our country’s ability to enhance its development for the benefit of its own people.
Question 3.
Collect pictures related to the landing of man on the moon and make a scrap file. You may also collect information about dates on which certain celestial bodies like Mars were seen from the earth.
Answer:
Do yourself.
DAV Class 6 Social Science Chapter 1 Question Answer – The Planet Earth and the Solar System
A. Tick (✓) the correct option.
Question 1.
Heavenly bodies include
(a) the sun
(b) the planet
(c) both (a) and (b)
(d) neither (a) nor (b)
Answer:
(c) both (a) and (b)
Question 2.
All the stars in a huge cluster are hold together by mutual
(a) gravitational force
(b) centrifugal force
(c) centripetal force
(d) none of these
Answer:
(a) gravitational force
Question 3.
The number of planets is
(a) 7
(b) 8
(c) 9
(d) 10
Answer:
(b) 8
Question 4.
The rays of the sun reach the earth’s surface in about
(a) 30 minutes
(b) 15 minutes
(c) 10 minutes
(d) 8 minutes
Answer:
(d) 8 minutes
Question 5.
What is the correct order of the planets as per their distances from the sun?
(a) Mercury, Earth, Mars, Venus, Jupiter, Saturn, Neptune and Uranus.
(b) Mars, Mercury, Venus, Earth, Saturn, Jupiter, Uranus and Neptune.
(c) Mercury, Jupiter, Saturn, Earth, Mars, Uranus, Neptune and Venus.
(d) Mercuiy, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Answer:
(d) Mercuiy, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Question 6.
Which of the following planets is not a gaseous body?
(a) Saturn
(b) Uranus
(c) Venus
(d) Neptune
Answer:
(c) Venus
Question 7.
Which of the following planets is closest to the sun?
(a) Mercury
(b) Venus
(c) Saturn
(d) Jupiter
Answer:
(a) Mercury
Question 8.
Which of the following heavenly bodies has a long luminous tail?
(a) Asteroid
(b) Comet
(c) Meteorite
(d) Satellite
Answer:
(b) Comet
B. Very Short Answer Type Questions
Question 1.
What is the universe made up of?
Answer:
It is made up of a large number of galaxies.
Question 2.
What is Milky Way made up of?
Answer:
It is made up of billions of stars.
Question 3.
What do you know about ‘Proxima Centauri?
Answer:
It is the nearest star to the earth, other than the Sun. It is about 4’A light years away from us.
Question 4.
What do the space scientists and astronomers use to study the celestial bodies?
Answer:
They use powerful and large-sized telescopes to study the celestial bodies.
Question 5.
Name the members of the solar system.
Answer:
- Eight planets
- Satellites
- Asteroids
- Meteors, and
- Comets.
Question 6.
What is the distance between the earth and the Sun?
Answer:
The distance between the earth and the sun is about 150 million kilometres.
Question 7.
From where do the planets get light and heat?
Answer:
They get light and heat from the sun.
Question 8.
Name the planets which are made up of solid material?
Answer:
Mercury, Venus, Earth and Mars.
Question 9.
What time does the Mercury take to complete one rotation?
Answer:
The Mercury takes 59 days to complete one rotation.
Question 10.
What time does the earth take to complete one revolution around the sun?
Answer:
The earth takes one year i.e., 365 days and 6 hours to complete one revolution around the sun.
Question 11.
What time does the earth take to complete one rotation on its axis?
Answer:
The earth takes one day i.e., 24 hours to complete one rotation.
Question 12.
Name the two planets which do not have any satellite.
Answer:
Mercury and Venus.
Question 13.
What time does the moon take to complete one rotation on its axis and one rovolution around the earth?
Answer:
The moon takes the same time, that is 27 days and 7 hours to complete one rotation on its axis and one revolution around the earth.
Question 14.
What do you know about the surface of the moon?
Answer:
The surface of the moon is rough and irregular. There are high volcanic cones, deep valleys filled with rock material and large craters. It is totally a barren land.
Question 15.
When is it full moon day?
Answer:
The day when the moon is completely visible to us, is the full moon day.
Question 16.
Name the largest asteroid. Mention its diameter.
Answer:
Ceres. Its diameter is more than 1000 km.
Question 17.
How are craters formed?
Answer:
Sometimes meteorites crash on the ground with great force and form deep craters.
Question 18.
What are comets made up of?
Answer:
Comets are made up of dust and frozen gases.
Question 19.
Why is Venus the hottest planet?
Answer:
Venus is the hottest planet due to its dense atmosphere.
Question 20.
What do you understand by the term light year?
Answer:
Light year is the unit used for measuring the distances between various celestial bodies.
C. Short Answer Type Questions
Question 1.
There is a great variation in time taken by each planet to complete one rotation on its axis and one revolution around the sun. Explain it with examples.
Answer:
It is true that time taken by each planet to complete one rotation and one revolution varies greatly. For example, the Mercury completes one rotation in 59 days and one revolution in 88 days. The Venus rotates very slowly and completes one rotation in 244 days but revolves around the sun in 225 days. Jupiter rotates in about 10 hours and revolves round the sun in about 12 years.
Question 2.
Why is life not possible on the moon? Give reasons.
Answer:
The moon does not have atmosphere around it. It becomes extremely hot during the day time in the light of the sun and extremely cold during night or in shadow. The temperature may increase to more than 135°C during the day and falls down to -170°C during the night. It is, therefore, life is not possible on the moon.
Question 3.
What are meteors? Write three points about them.
Answer:
- Meteors are veiy small planetary masses which often enter earth’s atmosphere and get burnt due to friction.
- They appear as bright objects and are called shooting stars.
- Sometimes, they crash on the ground with great force and form deep craters.
Question 4.
Mention three characteristics of a satellites.
Answer:
- A satellite is a heavenly body that revolves around its respective planet.
- It does not have its own light and heat.
- It reflects light, which it receives from the Sun.
D. Long Answer Type Questions
Question 1.
Write short notes on the following:
(a) The sun
(b) The moon
(c) Galaxy
Answer:
(a) The sun is considered the “head” of the solar system. It is a star, although it is smaller and less bright than most other stars. It is a huge celestial body made up of extremely hot gases. It provides heat and light for the whole of the solar system. Life on earth depends on many factors, and sunlight is one of them. The sun is about 150 million kilometres away from earth.
(b) The moon is the only natural satellite of our planet earth. Its diameter is just about a quarter of the earth’s diameter. It is comparatively closer (3,84,400 kilometres away) to earth than all other celestial bodies. It does not support life. It revolves around the earth and rotates about its own axis in about the same time, due to which only one side of the moon is visible to us.
(c) Galaxy is a term that refers to billions of stars, clouds of dust and gases, and other celestial bodies considered as a single unit. The only bigger unit is the universe, i.e. galaxies make up the universe. The galaxy we live in is called the Milky Way.
Question 2.
Draw a diagram showing the eight planets of the solar system in their orbits around the sun. Also prepare a table mentioning the rotation and revolution time of the eight planets.
Answer:
The rotation time and revolution time of the eight planets are as follows:
| Planets | Rotation Time | Revolution Time around the Sun |
| Mercury | 59 days | 88 days |
| Venus | 243 days | 225 days |
| Earth | 24 hours | 365 days and 6 hours |
| Mars | Little over 24 hours | 687 days |
| Jupiter | 10 hours | 12 years |
| Saturn | 10.7 hours | 29 years |
| Uranus | 17 hours | 84 years |
| Neptune | 16 hours | 165 years |