DAV Class 5 Science Solution Chapter 12 Observing the Sky
DAV School Books Class 5 Science Solution Chapter 12 Observing the Sky all Question Answer. DAV Class 5 12th Chapter Observing the Sky full Chapter explanation by expert teacher.
A.) Fill in the blanks.
Answer: (1) constellation (2) closer (3) wandering star (4) north (5) twinkle,twinkle.
B.) Match the following:
1. A constellation visible in winter | a. Sun |
2. The morning star | b. moon |
3. A constellation visible in spring | c. Orion |
4. Brightest object in the night sky | d. Ursa Major |
5. A star of average brightness | e. Mercury and venus |
Answer: (1) c, (2) e, (3) d, (4) b, (5) a.
C.) Tick the correct option.
1.) The planet that can be (sometimes) seen in the evening sky, even with unaided eye, is-
Answer: (c) Mercury
2.) The two stars, at the top of Ursa Major, are called-
Answer: (d) Pointers
3.) The Cassiopeia is-
Answer: (d) a constellation visible in autumn.
4.) From the following, the object in the sky, that (apparently) moves least in a given time is-
Answer: (a) North Star
5.) The brightest planet in the night sky is-
Answer: (b) Venus
6.) On closely observing some bright stars, for some hours, one finds that stars appear to move from-
Answer: (a) east to west
D.) Answer the following questions in brief.
1.) Why do, we usually not see the stars during the day?
Even though stars are present in the sky all the time they are only visible during nighttime and not during daytime due to the brightness of Sunsome at that point of time
2.) In which part of the sky are we likely to find Venus when it is visible as an evening star?
Answer: west direction.
3.) State the cause of the apparent motion of the sun from east to west?
Answer:
The seeming motion of the sun from east to West is due to the rotation of the earth on its own axis from West to east.
4.) Name the special star in the northern hemisphere. Why has it been useful for travellers?
The pole star is present in the north hemisphere and is used by navigators because it appears to be fixed at one position because it lies almost along the axis of rotation of the earth.
E.) Answers the following questions.
1.) Define the term ‘constellation’.
Answer: Group of stars that imitate a certain figure and form a different pattern in the sky are known as a constellation
2.) In what respects is, the pole star, different from other stars?
Answer: the pole star like another stars seems fixed at one position due to it being at the tip of the axis of rotation of the earth. This is why its position remains fixed and it becomes easier for others to navigate using its position
3.) Write two points of difference between a planet and a star.
Planets | Stars |
Planets might be composed of rocks, metals , gases or a combination of all | Stars are only made of gases like hydrogen and helium |
Planets do not twinkle | Stars are seen twinkling in the night sky |
4.) Why do stars appear to slightly shift their position in the night sky?
Answer: Due to the revolution of the earth along its orbit the position of the stars seemed to appear slightly shifted from their position in the night sky
5.) Why do stars appear as points to us?
Stars appear as small or dim points in the sky because they are at light years away from us which is a very large distance due to this they appear very hazy toward eyes.