NCERT Solutions class 8 Science 17. Stars And The Solar System Additional Questions With Solutions

Additional Questions With Solutions

Ques : What are celestial object?
Ans : The stars, the planets, the moon and many other objects in the sky are called celestial objects.

Ques : Why the village skylooks clear from the night sky inbig cities?
Ans : In big cities is rarely clear due to bright light, smoke and dust, sky. There are no bright lights in the village sky and the atmosphere is clear.

Ques : Define full moon day.
Ans : The day on which the whole disc of the moon is visible is known as the full moon day.

Ques : What are phages of the moon?
Ans : The various shapes of the bright part of the moon as seen during a month are called phases of the moon.

Ques : What is the new moon day?
Ans : On the fifteenth day the moon is not visible. This day is known as the new moon day.

Ques : What is the crescent moon?
Ans : The next day of the new moon day, only a small portion of the moon appears in the sky. This is known as the crescent moon.

Ques : The moon has not it own light as stars but how do we able to see the moon?
Ans : We see the moon because the sunlight falling on it gets reflected towards us.

Ques : Why is the life not possible on the moon?
Ans : The moon has no useful substances for living like atmosphere and it has no water.

Ques : Define Light year?
Ans : The distance travelled by light in one year known as light year.

Ques : What is a constellation?
Ans : The stars forming a group that has a recognisable shape is called a constellation.

Ques : Write the situation of pole stare.
Ans : The Pole star lies close to the axis of rotation of the Earth.

Ques : When can you see the Great bear constellation or Saptarishi Tara Mandal?
Ans : We can see Great bear constellation or Saptarishi Tara Mandal during the summer time in the early part of the night.

Ques : Which constellation moves around the pole star?
Ans : Ursa Major Or Great Bear.

Ques : When can the Orion see in the sky?
Ans :   Orion is another well-known constellation that can be seen during winter in the late evenings

Que : What is satellite?
Ans : A body revolving around another body is called a satellite.

Que : Write the type of satellites.
Ans: There are two type of satellites.

1. Natural satellite – The moon
2. Artificial Satelite – Aryabhatt, INSAT, IRS and KalpanAns : I etc.

Que : Name the first natural satellite of India.
Ans : Aryabhatta.

Que : Differentiate between natural and artificial satellite.
Ans :

Que : Define orbit?
Ans: A planet has a definite path in which it revolves around the Sun. This path is called an orbit. 

Que : Write the use of artificial satellites.
Ans :

1. They are used for forecasting weather, transmitting television and radio signals.
2. They are also used for telecommunication and remote sensing.

Que: Explain Period of revolution.
Ans : The time taken by a planet to complete one revolution is called its period of revolution.

Que : What is revolution?
Ans : The movement of planets around the sun on their orbit is called revolution.

Que : What is rotation ?
Ans : The planets move on their own axis like top, Such movement s known as rotation.