Q1Multiple choice
Morning star is the name given to
- (a)pole star
- (b)star Sirius
- (c)planet Jupiter
- (d)planet Venus
Show answer
(d) planet Venus
Chapter 17 – Stars And Solar System
Class 8 Science · 24 questions · 22 with answers
Questions
Q2Multiple choice
Which of the following figures depicts the position of pole star correctly?
This question refers to a figure in the original PDF.
- (a)
- (b)
- (c)
- (d)Fig. 17.1
Show answer
(a)
Q3Multiple choice
Sun appears to move from east to west around the earth. This means that earth rotates from
- (a)east to west
- (b)west to east
- (c)north to south
- (d)west to north 98 E XEMPLAR PROBLEMS
Show answer
(b) west to east
Q4Multiple choice
An astronaut standing on the surface of the moon throws a ball upwards. The ball would
- (a)directly fall down from the point it is released.
- (b)hang in space.
- (c)go up and then come back to the surface of the moon.
- (d)keep going up never to come back.
Show answer
(c) go up and then come back to the surface of the moon.
Q5Multiple choice
Suppose a new planet is discovered between Uranus and Neptune. Its time period would be
- (a)less than that of Neptune.
- (b)more than that of Neptune.
- (c)equal to that of Neptune or Uranus.
- (d)less than that of Uranus.
Show answer
(a) less than that of Neptune.
Q6Multiple choice
The change in seasons on the earth occurs because
- (a)the distance between the earth and the sun is not constant.
- (b)the axis of rotation of the earth is parallel to the plane of its orbit.
- (c)the axis of rotation of the earth is perpendicular to the plane of its orbit.
- (d)the axis of rotation of the earth is tilted with respect to the plane of its orbit.
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(d) the axis of rotation of the earth is tilted with respect to the plane of its orbit.
Q7Multiple choice
The first of a month is the new moon day. On fifteenth of the same month, which of the following figures would represent the phase of the moon?
This question refers to a figure in the original PDF.
- (a)
- (b)
- (c)
- (d)Fig. 17.2 S TARS AND SOLAR SYSTEM 99
Show answer
(a)
Q8Very short answer
Do stars emit light only during night?
Show answer
No, they emit light all the time.
Q9Very short answer
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?
Show answer
Boojho is correct.
Q10Multiple choice
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.
Show answer
(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.
Q11Very short answer
John saw full moon on a particular day. After how many days will he be able to see the full moon again?
Show answer
Approximately 29 days.
Q12Very short answer
In the picture of rotating earth given as Fig. 17.3 mark the position of pole star. Fig. 17.3 100 E XEMPLAR PROBLEMS
This question refers to a figure in the original PDF.
Q13Very short answer
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. (B) (A) (C) (D) Fig. 17.4
This question refers to a figure in the original PDF.
Show answer
C ANSWERS 153
Q14Very short answer
In Fig. 17.5 mark the arrows (←), (→), (↓), or (↑) to show the direction of sunlight. Fig. 17.5 S TARS AND SOLAR SYSTEM 101
This question refers to a figure in the original PDF.
Show answer
(←) SHORT ANSWER QUESTIONS
Q15Short answer
A star is ten light years away from the earth. Suppose it brightens up suddenly today. After how much time shall we see this change?
Show answer
We will see the change after 10 years.
Q16Short answer
Meteors are not visible during the daytime. Explain the reason.
Show answer
The brightness of a meteor is extremely small compared to that of the sun, therefore, it is not seen during day time.
Q17Short answer
Why does the moon change its shape daily?
Show answer
It changes its shape because we see only that part of the moon from which the light of the sun is reflected towards us.
Q18Short answer
Paheli saw the moon through a glass window at 8:00 p.m. She marked the position of the moon on the glass pane. She got up at 4 a.m. in the morning. Will the moon be visible at the same position?
Show answer
No, because the position of the moon keeps changing during the night. LONG ANSWER QUESTIONS
Q19Long answer
Suppose the moon emits light of its own. Would it still have phases? Justify your answer.
Show answer
No. The phases are seen because the moon does not emit its own light and reflects the light of sun.
Q20Long answer
Fig. 17.6 shows comets without their tail. Show the tails of the comets at position A, B, and C. In which position will the tail be longest? Fig. 17.6 102 E XEMPLAR PROBLEMS
This question refers to a figure in the original PDF.
Show answer
The tail will be longest at position B. 154 E XEMPLAR PROBLEMS
Q21Multiple choice
Explain why we always see the same side of moon. 22. Fig. 17.7 Look at Fig. 17.7 carefully and answer the following question:
This question refers to a figure in the original PDF.
- (a)In which part of the sky would you see the full moon in the evening?
- (b)In which part of the sky would you see the crescent moon in the evening?
Show answer
This is because the period of rotation of the moon on its axis is equal to the period of its revolution round the earth.
Q23Long answer
Write the names of all planets in Fig. 17.8. Fig. 17.8 S TARS AND SOLAR SYSTEM 103
This question refers to a figure in the original PDF.
Q24Long answer
Suppose the distance between earth and sun becomes half of its present distance. What is likely to happen to life?
Show answer
Hint: Life may no longer exist. (See page 227-228 of textbook)
Q25Long answer
Explain with a diagram how you can locate pole star with the help of the constellation Great Bear (Ursa Major).
Show answer
Locate the two end stars of Ursa Major. Imagine a straight line passing through these stars as shown in the figure below. Extend this imaginary line towards the north direction. This line will lead to a star which is not too bright. This is pole star. ANSWERS 155