17. Stars And The Solar System Science class 8 in English Medium ncert book solutions Additional Questions With Solutions

Additional Questions With Solutions

Que: What are celestial object?

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

Que: 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.

Que: Define full moon day.

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

Que: 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.

Que: 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.

Que: 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.

Que: 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.

Que: 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.

Que: Define Light year?

Ans: The distance travelled by light in one year known as light year.

Que: What is a constellation?

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

Que: Write the situation of pole stare.

Ans: The Pole star lies close to the axis of rotation of the Earth.

Que: 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.

Que: Which constellation moves around the pole star?

Ans: Ursa Major Or Great Bear.

Que: 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.