Solution of Chapter 17. Stars and The Solar System (NCERT - Science Book)

Exercises

1

Which of the following is NOT a member of the solar system?

(a) An asteroid


(b) A satellite


(c) A constellation


(d) A comet
2

Which of the following is NOT a planet of the sun?

(a) Sirius


(b) Mercury


(c) Saturn


(d) Earth
3

Phases of the moon occur because

(a) we can see only that part of the moon which reflects light towards us.


(b) our distance from the moon keeps changing.


(c) the shadow of the Earth covers only a part of the moon's surface.


(d) the thickness of the moon's atmosphere is not constant.
4

Fill in the blanks:

(a) The planet which is farthest from the sun is ___________.


(b) The planet which appears reddish in colour is___________.


(c) A group of stars that appear to form a pattern in the sky is known as a ___________.


(d) A celestial body that revolves around a planet is known as a ___________.


(e) Shooting stars are actually not ___________.


(f) Asteroids are found between the orbits of ___________ and ___________.
5

Mark the following statement as true (T) or false (F).

(a) Pole star is a member of the solar system. ( )


(b) Mercury is the smallest planet of the solar system. ( )


(c) Uranus is the farthest planet in the solar system. ( )


(d) INSAT is an artificial satellite. ( )


(e) There are nine planets in the solar system. ( )


(f) Constellation Orion can be seen only with a telescope. ( )
6

Match items in column A with one or more items in column B.


A



B



(i)



Inner planets



(a)



Saturn



(ii)



Outer planets



(b)



Pole star



(iii)



Constellation



(c)



Great Bear



(iv)



Satellite of the Earth



(d)



Moon




(e)



Earth



(f)



Orion



(g)



Mars
7

In which part of the sky can you find Venus if it is visible as an evening star?
8

Name the largest planet of the solar system.
9

What is a constellation? Name any two constellations.
10

Draw sketches to show the relative position of prominent stars in (a) Ursa Major and (b) Orion.
11

Name two objects other than planets which are members of the solar system.
12

Explain how you can locate the Pole Star with the help of Ursa Major.
13

Do all the stars in the sky move? Explain.
14

Why is the 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?
15

The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accommodate?
16

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