Stars and the Solar System - Exemplar Solutions 2

CBSE Class 8 Science
NCERT Exemplar Solutions

8. Do stars emit light only during night ?
Ans: The stars are present in the sky even during the day-time. But they are not visible during daytime because of the bright sunlight.

9. Paheli and Boojho observe a bright object in the night sky which was not twinkling. Paheli says, it is a star and Boojho says it is a planet. Who is correct ?
Ans: The planets look like stars, but they do not have light of their own. They reflect the sunlight falling on them. Boojho is correct, the object was planet.

10. State whether the following statements are ‘True’ or ‘False’.
(a) The planet nearest to us is Jupiter.
(b) All the stars are at the same distance from us.
(c) The planets do not emit light of their own.
(d) The planets keep changing their position with respect to stars.
(e) The planet Venus appears in the eastern sky before sunrise.
(f) The plane in which the earth revolves around the sun is called equatorial plane of earth.
Ans: a. False – The next planet after Earth is Mars.
b. False – The stars are at different distances.
c. True
d. True
e. True
f. False – The plane in which the Earth revolves round the sun is known as orbital plane of the Earth.

11. John saw full moon on a particular day. After how many days will he be able to see the full moon again ?
Ans: John will be able to see the next full moon in slightly longer than 29 days.

12. In the picture of rotating earth given as Fig. 17.3 mark the position of pole star.
Ans: The pole star is situated in the direction of the earth’s rotation axis.

13. In the given Fig. 17.4 out of the positions A, B, C and D which will indicate the position of the sun ? Draw the sun at the appropriate position.
Ans: (C)

14. In Fig. 17.5 mark the arrows (←), (→), (↓), or (↑) to show the direction of sunlight.