CBSE Class 8 Science Stars and the Solar System Assignment

A.TICK THE CORRECT OPTIONS:

Question. When the moon is in between the Earth and the Sun, we see_____________ .
(a) New moon
(b) Full moon
(c) Quarter moon
(d) Crescent moon
Answer. a New moon

Question. Which of the following is not an inner planet?
(a) Mercury
(b) Neptune
(c) Mars
(d) Earth
Answer. b Neptune

Question. The planet that has minimum time period of rotation is the______________ .
(a) Earth
(b) Mercury
(c) Venus
(d) Jupiter
Answer. d Jupiter

Question. Which of the following has no satellite?
(a) Saturn
(b) Venus
(c) Neptune
(d) Jupiter
Answer. b Venus

Question. Which of the following planets is the largest planet of the solar system?
(a) Jupiter
(b) Earth
(c) Uranus
(d) Saturn
Answer. Jupiter

B.FILL IN THE BLANKS
1. The ________is the brightest star in the sky at night.
2. Orion constellation is also called the _________constellation.
3. ____________ comet appears nearly after every 76 years.
4. A meteoroid that lands on the Earth’s surface is called_________.
5. Ursa Major is also called _________________________.
6. Pole Star is not visible in _________________________.
7. The full moon night is also called __________________.
8. The moon rotates about its axis in about the __________ time that it to orbit the Earth.
Answer.
1.Sirius       4. Meteorite                      7. Purnima
2.Hunter     5.Great Bear constellation  8. 27days 8 hours
3. Halley’s   6.Southren hemisphere

C. VERY SHORT ANSWER QUESTIONS:

Question. What is the temperature of the moon’s surface (a) in daytime (b) at night?
Answer. The temperature of the moon’s surface is
(a) In daytime = 123o C (b) at night = --- 233o C

Question. In which parts of the sky can you find Venus if is visible as an evening star?
Answer. Venus appears in the western sky after sunset that is why it is called as evening star.

Question. Name the largest planet in our solar system.
Answer. The largest planet in our universe is Jupiter.

Question. Name two planets that rotate from the east to the west.
Answer. Venus and Uranus are the two planets that rotate from the east to the west.

Question. What is a comet?
Answer. A comet is a small body of ice and dust that revolves around the sun in highly elliptical orbit.

Question. Name two dwarf planets.
Answer. Two dwarf planets are Pluto and Ceres.

D. SHORT ANSWER QUESTIONS:

Question. Why does the Sun appear to be larger and brighter than other stars?
Answer. The Sun appear to be larger and brighter than other stars because it is closer to the Earth than any other star.

Question. Which planet is called red planet and why?
Answer. Mars is called as red planet as its whole surface is covered with red coloured dust (iron oxide) and rock.

Question. Why does the pole star appear stationary?
Answer. Pole star is situated above the axis of rotation of the earth, so it appears stationary from the earth.

Question. What do you mean by light year?
Answer. One light year is the distance travelled by the light in one year, that is equal to 9.46x 1012 Km.

Question. Why can we never see the backside of the moon from the Earth?
Answer. We never see the backside of the moon from the Earth because the moon rotates about its axis in about the same time that it takes to orbit the Earth. This results in the same face turned towards the Earth at all times.

Question. What are asteroids?
Answer. Asteroids are small irregular shaped heavenly bodies of rocks and metals that revolve around the Sun in the gap between the orbits of Mars and Jupiter.

Question. Write any three points about Ursa Minor constellation.
Answer. (1) It is clearly seen in the northern part of the sky in July during the summer season.
(2) There are seven prominent stars in this constellation that form the shape of a dipper.
(3) At the end of the tail of Ursa Minor is the pole star.

Question. Why does life exists on the Earth? Write three conditions.
Answer. The Earth is at the right distance from the Sun. So, it has some special environmental conditions like right temperature range, the presence of water, a suitable atmosphere and a blanket of ozone. These are responsible for the existence and continuation of life on the Earth.

Question. Write any three differences between meteors and meteorites.
Answer.

G. Long Answer Questions:

Question. What is meant by the following phases of the moon: -
(a) New moon, (b) crescent moon, (c) first quarter moon, (d) gibbous moon and (e) full moon?
Answer. (a) New moon:-
When the moon is between the Earth and the Sun and we do not see the moon at all, it is called new moon. It is also known as Amavasya.

(b) Crescent moon:-
When we see a small sun – lit portion of the moon, it is called crescent moon. The increasing size of the lighted part of the moon is called waxing crescent moon where as the decreasing size of the lighted part of the moon is called waning crescent moon.

(c) first quarter moon:-
After new moon, when we see half the moon, it is called the first quarter moon.

(d) Gibbous moon:-
When we see more than half of the moon, it is called gibbous moon. The increasing and decreasing size of the lighted part of the moon is called waxing and waning gibbous moon.

(e) Full moon:-
After two weeks when the whole sun –lit portion of the moon is visible, it is called full moon. The full moon night is called `purnima’. The full moon is very bright because of the maximum moonlight.

Question. Differentiate between a star and a planet.
Answer.

Question. (a) What are artificial satellites?
Answer. An artificial satellite is a human-made object that has been placed into the orbit around the Earth or other planets to perform specific fuctions.
First artificial satellite was Sputnik-I by USSR and the first Indian satellite was Aryabhatta.

(b) Give three uses of artificial satellites.
Answer. Artificial satellites are used for:-
1. Forecasting weather
2. Transmitting radio and television signals.
3. Telecommunication- -- cellular phones and long distance telephones, fax,etc., are few of the services provided by satellite communication.

Question 1- Which of the following is NOT a member of the solar system?

 

Question 13. Do all the stars in the sky move? Explain.

Answer- No, no star moves in sky. They appear to move from east to west, because the Earth rotates from

west to east about its axis.

 

Question 14. Why is distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the earth?

Answer- The distance of stars is so large that it cannot be expressed in terms of kilometer. That is why very large distances are expressed in another unit known as light year. One light year is the distance travelled by light in one year. If the distance of a star is eight light years, it means that this distance is the distance travelled by light in eight years.

 

Question 15. The radius of Jupiter is 11 times the radius of Earth. Calculate the ratio of the volumes of Jupiter and the earth. How many earths can Jupiter accommodate?

Answer- If the radius of the Earth is r.

Then, radius of the Jupiter is 11r.

So, the ratio of Volume of Jupiter and the earth = [4/3π(11r)³] / [4/3π (r)³] = 1331 : 1

So, we cwn say that Jupiter can accommodate 1331 earths.

 

Question 16. Boojho made the following sketch (fig. 17.29) of the solar system. Is the sketch correct? If not, correct it.

Answer- The positions of Mars and Venus should be interchanged. Similarly positions of Neptune and Uranus should be also interchanged.

ONE MARK MCQs

More Question

Q1. Define the following terms:-

a. Orbit

b. Satellite

c. Constellation

Q2. Explain, why can we see full moon on a full moon day while it is not visible on a new moon day?

Q3.We never see the back side of moon from the earth , Why?

Q4. Explain, with the help of diagram, how is moon visible to us when it does not have light of its own?

Q5. Can we hear any sound on moon? Comment.

Q6.Give reasons for the following:-

(a) Stars appear to us as points objects

(b) Stars are not are present in the day time also but we are not able to see them.

(c)Earth is called a unique planet.

(d) Stars appear to move from east to west.

Q7. In which part of the sky can you find Venus if it is visible as a morning star?

Q8. What is pole star? Where does it lie?

Q9. How can you locate the star Sirius with the help of Orion Constellation?

Q10. A star is 7 light years away from earth. What do you mean by the statement? Also calculate thec distance in km.

Q11. Distinguish between

(a) Stars and planets

(b) Meteors and Meteorites

(c) Period of rotation and period of revolution

(d) Asteroids and comets

Q12. How does earth look like when observed from space?

Q13. What causes the change of season on earth?

Q14. What makes Saturn unique in the solar system?

Q15. Name the following:-

a) Red planet of our solar system

b) Planet which has a large number of satellites

c) Planet which is the least dense among all the planets

d) Brightest planet in the Solar System

e) The constellation which looks like the letter W or M

f) Smallest planet of our solar system

g) Planet which shows phases like moon.

STARS AND THE SOLAR SYSTEM

1.On full moon day:
(A) Moon lies in between the Earth and the Sun.
(B) Earth lies in between the moon and the Sun.
(C) Sun lies in between the Earth and the moon.
(D) None of them.

2.Which planet has 30 satellites:
(A) Saturn.
(B) Pluto.
(C) Uranus.
(D) Jupiter.

3.Time taken by the Earth to go once around the Sun is:
(A) 365 days.
(B) 365.45 days.
(C) 365.75 days.
(D) 365.25 days.

4.Halley's comet appears after every:
(A) 75 years.
(B) 73 years.
(C) 76 years.
(D) 72 years.

5.Moon's surface is:
(A) Smooth.
(B) Fertile.
(C) Dusty and barren.
(D) None.

6.Pole star changes its position in the sky because:
(A) It is an imagination.
(B) It lies on the axis of rotation of earth.
(C) It lies on 30° to the axis of rotation of earth.
(D) Moon kept it stationary in sky.

7.Write the name of first satellite of India.

8.What is a natural satellite?

9.Why do we classify the sun as a star?

10.Which comet appears after every 76 years?

11.Name any two artificial satellites of our country.

12.Name a star that always appear stationary from earth's surface?

13.What do you mean by the term phases of moon?

14.What are celestial bodies?

15.Why the village sky is so different from the night sky in big cities?

16.The star nearest to the Earth after the Sun is:
(A) Alpha Centuari.
(B) Pole star.
(C) Shooting star.
(D) Moon.

17.Light year is equal to
(A) 9.46 x 1012 km.
(B) 3,00,000 x 365 x 24 x 60 x 60 km.
(C) 9,460,000,000,000 km
(D) All of them

18.Polaris' is the name given to a star situated in the north direction. The other name of the star is
(A) Great bear.
(B) Orion.
(C) Pole star
(D) Ursa minor.

19.Distance between the stars is measured in:
(A) Kilometers.
(B) Meters.
(C) Light years.
(D) Chandra Shekhar Limit.

20.Which of the following planet is called morning star:
(A) Venus.
(B) Mercury.
(C) Pluto.
(D) Neptune.

21.Venus is brightest planet because of:
(A) Ozone layer around it.
(B) Cloudy atmosphere of nitrogen.
(C) Cloudy atmosphere of carbon dioxide.
(D) Layer of jugnus around it.

22.Which of the following statements is false about Venus?
(A) Venus keeps its same face towards the sun
(B) Its day side temperature is too high and night side temperature is too low.
(C) It has a thick atmosphere of carbon dioxide, which contributes to its excessive dayside temperature.
(D) It rotates from west to east about its axis.

23.Change of seasons on the earth takes place due to the reason that:
(A) The axis of rotation of the earth is tilted at an angle of ° with the vertical.
(B) The earth is not always at the same distance from the sun, on account of its slightly elliptical orbit around the sun.
(C) Both (a) and (b).
(D) None of these.

24.Match the following:

Column I                           Column II

I. Coldest planet                   A.Mars

II. Bluish planet                    B.Saturn

III. Plant with rings around   C. Uranus

IV. Red planet                      D. Pluto

(A) I-B, II-A, III-D, IV-C (B) I-C, II-B, III-A, IV-D

(C) I-D, II-C, III-B, IV-A (D) I-A, II-D, III-C, IV-B

25.Match the following:

Column I                                    Column II

IDon't twinkle                                A.Meteors

II.Group of stars                           B.Planets

III.Burning pieces of rocks           C.Asteroids

IV.A belt of debris between   D.Constellation Mars and Jupiter
(A) I-B, II-D, III-A, IV-C
(B) I-C, II-A, III-B, IV-D
(C) I-D, II-B, III-C, IV-A
(D) I-A, II-C, III-D, IV-B

26.Which of the following can reach on the surface of earth:
(A) Meteors.
(B) Meteorite.
(C) Comets.
(D) Asteroids.

27.What reason you assign for the formation of day and night on the earth?
(A) Revolution of sun around the earth
(B) Revolution of earth around the sun
(C) Revolution of earth on its own axis
(D) Revolution of moon around earth

28.On new moon day
(A) The moon is between the sun and earth.
(B) The sun is between the moon and earth.
(C) The earth is between the sun and moon.
(D) None of these.

29.Jupiter's red spot is really a:
(A) A big storm.
(B) A layer of red clouds.
(C) An active volcano.
(D) A river of blood.

30.A group of stars forming some recognizable shape are known as
(A) Galaxy.
(B) Constellation.
(C) Comets.
(D) Asteroids.

31.Which of the following is natural satellite of a planet?
(A) Phobos.
(B) Vagus.
(C) Deimos.
(D) Both (a) and (c).

32.Halley comet was last seen in:
(A) 1910.
(B) 1986.
(C) 1923.
(D) 1999.

33.Which of the following planet has largest numbers of moons ?
(A) Saturn.
(B) Uranus.
(C) Earth.
(D) Jupiter.

34.In how much time moon completes one revolution around the earth?
(A) 27(1/3) days.
(B) 29(1/2)days.
(C) 15 days.
(D) 30 days.

35.Moon always presents same face towards the earth because:
(A) Moon completes one revolution between one new moon to next new moon in 29(1/2) days.
(B) It takes exactly the same time to spin once about its axis.
(C) The moon completes one revolution around the earth in29(1/2) days.
(D) The moon absorbs the light from sun.

36.Shooting star is a:
(A) Meteor.
(B) Meteorite.
(C) Asteroid.
(D) Comet.

37.Large number of small bodies between the orbits of Mars and Jupiter that revolve around the sun are called:
(A) Comets.
(B) Meteors.
(C) Meteorites.
(D) Asteroids.

38.Which of the following does not operates through satellites?
(A) Transport system.
(B) Mobile phones.
(C) Internet.
(D) Television programme.

39.Remote sensing means:
(A) Collecting information from a distance.
(B) Breaking a remote.
(C) Marketing of remote.
(D) None of these.

40.Which of the following is false about satellites:
(A) Long distance transmission of television programme becomes possible with the help of artificial satellites.
(B) Artificial satellites are also used to gather information about movements of materials concerning defence activities.
(C) Artificial satellites are also used for research.
(D) Moon is much closer to earth than the artificial satellites.

41.Which planet takes minimum time in one revolution around sun:
(A) Earth.
(B) Jupiter.
(C) Mercury.
(D) Saturn.

42.Which out of the following has density less than water:
(A) Earth.
(B) Jupiter.
(C) Mercury.
(D) Saturn.

43.The MilkyWay Galaxy is …………….. in shape.
(A) Spherical.
(B) Elliptical.
(C) Spiral.
(D) None.

44.Venus is …………than Mercury.
(A) Hotter.
(B) Colder.
(C) Smaller.
(D) None.

45.Which of the following is not a member of the solar system?
(A) A constellation.
(B) A satellite.
(C) A comet.
(D) An asteroid.

46.Which of the following is not a planet of the sun?
(A) Mercury.
(B) Saturn.
(C) Sirius.
(D) Earth.

47.The study of universe is known as:
(A) Astronomy.
(B) Aeronautics.
(C) Genomic.
(D) None.

<2M>

48.What are stars?

49.What is light year? What is its value in km?

50.What is pole star?

51.Write about solar system.

52.Give reason:
(i)Why does change in seasons on the earth occurs?
(ii)Why are phases of moon observed?

53.What are meteors? Why they are called shooting stars?

54.Explain constellations. Give an example also.

55.Can we hear any sound on the moon? Explain.

56.What are galaxies?

<3M>

57.Write uses of artificial satellites.

58.Write short notes on Meteors and Meteorites.

59.What is the difference between a star and a constellation?

60.Give one word for each:
(a) Stars forming a recoginsable pattern.
(b) A solid body from outer space that is sometimes able to reach the earth's surface.
(c) A belt of small planetoids present mainly in between the orbits of Mars and Jupiter.

61.What is moon? Explain

62.Write any three differences between Galaxy and Constellations.

63.What are the difference between natural satellite and Artificial Satellite.

<5M>

64.Show the relative positions of prominent stars in
(a) Ursa major and
(b) Orion in a diagram.

65.(i) What do you mean by solar system.
(ii) Which planet of the solar system is:
(a) The largest planet.
(b) The smallest planet.
(c) The brightest planet.
(d) The planet with rings.
The largest number of natural satellites.

66.What are the differences between a star and a planet?

67.What are the difference between natural satellite and Artificial Satellite