Sunday, April 22, 2012

Class 6 - Geography - Ch1 - THE EARTH IN THE SOLAR SYSTEM (#eduvictors)(#cbsenotes)


Class 6 - Geography - Ch1 - THE EARTH IN THE SOLAR SYSTEM (#eduvictors)(#cbsenotes)
Our Solar System

NCERT Textbook Solutions and other Questions and Answers

Q1: Answer the following questions briefly.
(a) How does a planet differ from a star?

  1. Stars emit their own light and heat. While planets do not have their own light.
  2. There are millions of stars while there are eight planets in our solar system.
  3. Usually stars twinkle at night while planets glow without any flickering.

(b) What is meant by the ‘Solar System’?

The sun, eight planets, satellites and some other celestial bodies known as asteroids and meteoroids form the solar system.The sun is in the centre of the solar system. All the planets of the solar system move around the sun in fixed paths.

(c) Name all the planets according to their distance from the sun.

Answer: Mercury, Venus, Earth.Mars, Jupiter, Saturn, Uranus, Neptune

(d)  Why is the Earth called a unique planet?

Following are the reasons the Earth is considered as a unique planet:
  • The land, water, air and the favourable climate facilitate the origin of life and help them in their development on the Earth. 
  • The earth is neither too hot nor too cold.
  • The air has life-supporting gases like oxygen.
  • No other planet of the solar family has a life like that of the Earth.

(e) Why do we see only one side of the moon always?

The moon moves around the earth in about 27 days. It takes exactly the same time to complete one spin. As a result, only one side of the moon is visible to us on the earth.

(f) What is the Universe?

Answer: A universe consists of millions of galaxies (such as Milky Way). It is vast and ever expanding. Space scientists speculate that the Universe had its origin some 15,000 million years ago.

Q2. Tick the correct answer.
(a) The planet is known as the “Earth’s Twin” is
(i) Jupiter
(ii) Saturn
(iii) Venus

Answer: (iii) Venus

(b) Which is the third nearest planet to the sun?
(i), Venus
(ii) Earth
(iii) Mercury

Answer:  (ii) Earth

(c) All the planets move around the sun in a/an (i) Circular path
(ii) Rectangular path
(iii) Elongated elliptical path
Answer:(iii) Elongated elliptical path.

(d) The Pole Star indicates the direction to the(i) South
(ii) North
(iii) East
Answer: (ii) North

(e) Asteroids are found between the orbits of(i) Saturn and Jupiter
(ii) Mars and Jupiter
(iii) The Earth and Mars
Answer:(ii) Mars and Jupiter

3. Fill in the blanks.

(a) A group of _stars__ forming various patterns is called a _constellation_.
(b) A huge system of stars is called_galaxy_.
(c) _The Moon__is the closest celestial body to our earth.
(d) _The Earth_is the third nearest planet to the sun.
(e) Planets do not have their own__light__ and _heat_.

 Choose the correct answer
4. The stars are not visible during the day because of their size
b) of their self-illumination
c) of their distance
d) of Sun’s brightness

Answer: d) of Sun's brightness

5. Which of the following is a natural satellite?
a. moon
c. IRS

Answer: a) moon.

6. Name the nearest star to the Earth.

Answer: Sun.

7. Name the nearest star to the Earth after the sun.

Answer:  Proxima Centauri

8. Why the earth is called a blue planet?

Answer: From the outer space, the earth appears blue because its two-thirds surface is covered by water. It is, therefore, called a blue planet.

9. How much time does it take to the light of the sun reach the earth?

Answer:  About eight minutes.

10. Name the first person who stepped on the surface of the moon.

Answer: Neil Armstrong

Q11: Why Venus is considered as ‘Earth’s Twin’?

Answer: Venus is considered as Earth Twin because its size and shape are very much similar to that of the Earth.

Q12: Why Earth is called the ‘Blue Planet’?

Answer: From the space, the Earth looks blue because of the presence of water on it. So, it is called ‘Blue Planet’.

Q13: What is a Constellation? What is the name of the constellation in Latin and English?

Answer: A group of star forming a particular pattern or design is called constellation Saptrishi is one such constellation. The constellation Saptrishi is called ‘Ursa Major’ in Latin and ‘Big Bear’ in English.

Q14: Which is the biggest member of the Solar System? Discuss it.

Answer: The Sun is the biggest member of the solar system. It is in the centre of the Solar System.
It is the source of heat and light. It is million times bigger than our Earth. The earth would
grow cold and lifeless without the solar energy.

Q15: How does the moon appear different each night?

Answer: The Moon revolves round the Earth. It has no light of its own. It only reflects the light of the Sun. The Moon neither decreases nor increases in reality, it only appears changed in its shape because of difference in light falling on it everyday.

Q16: What is an orbit?

Answer: All the planets of the Solar Family revolve around the Sun in elliptical path. It is known as orbit.

Q17: Write the major features of the Moon.

Answer: The Moon has been separated from the Earth, hence it is called a satellite of the Earth. Its diameter is only one-fourth of the Earth. It looks very big as it is not very far from the Earth. The Moon has mountains, plateau and depression on its surface. In the reflected light on the Earth these features look like shadows.

Q18: What is a Galaxy?

Answer: A galaxy is a huge system of stars. The white glowing path of stars across the sky is called the Milky Way galaxy. It has millions of stars close to one another. We in India call it Akash Ganga.

Q19: How did people in the past used to determine directions?

Answer: In the past people used to determine directions by watching the stars. The North Star or the Pole Star Indicates the North because it shines directly above the North Pole. It remains in the same direction in the sky, throughout the year.

Q20 Describe asteroids and meteoroids.

Asteroids- The heavenly bodies found between the orbits of Mars and Jupiter are called asteroids. They also revolve around the Sun. They are parts of a planet which was exploded many years back.

Meteoroids- Small pieces of rocks which revolve round the Sun are called meteoroids. When they enter the Earth’s atmosphere, they begin to burn. These burning rocks are called meteors. They cause a flash of light.

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