Stars

Q.

The twinkling of stars is due to atmospheric

1. dispersion of light by water droplets

2. refraction of light by different layers of varying refractive indices

3. scattering of light by dust particles

4. internal reflection of light by clouds

Q. What is constellations? Name and explain some major constellations.

Q.

Name the star (after the sun) which is closest to the Earth.

Q.

Why can't we easily see stars and planets in the sky when we are in a city, but can see them clearly from villages or countryside?

1. City lights obstruct the light coming from stars and planets

2. Because of light pollution in the cities

3. None of the above suits the explanation

4. The statement is not true

Q.

Do all the stars in the sky move? Explain.

Q.

What is the difference between a star and a shooting star?

Q.

What causes the twinkling of stars at night?

Q. The distance travelled by light in one year is called as ___.

1. light year
2. becquerel
3. decibel
4. None of the above

Q.

Why is the sun called a star? Explain with an example.

Q. Which one is the brightest star in the night sky?

1. Sun
2. Sirius
3. Pole Star
4. Proxima centauri

Q.

Give reasons:

The twinkling of stars

Q.

How is a star born ?

Q.

After the sun, the next nearest star to the Earth is:

(a) Alpha Centauri

(b) Pole Star

(c) Sirius

(d) Proxima Centauri

Q.

Do other stars revolve around the Sun?

1. Yes

2. No

3. Some stars do

4. Can't be determined

Q.

(a) In which direction do stars appear to move in the sky?

(b) Why do they appear to move in this direction?

Q. What is difference between pole star and Sirius

Q.

Fill in the following blanks with suitable words:

(a) The stars appear to ___ in the sky.

(b) The sun is a ___ whereas Orion is a ___.

(c) The group of stars that appears to form a recognisable pattern in the sky is know as ___.

(d) The brightest star in the night sky is ___.

(e) Ursa Major constellation appears to revolve around the ___ star in the night sky.

(f) Orion constellation can be used to locate the position of ___ star whereas Ursa Major constellation can be used to locate the ___ star in the night sky.

(g) The planet which is farthest from the sun is ___.

(h) The planet which appears reddish in colour is ___.

(i) The small heavenly bodies revolving around the sun between the orbits of mars and jupiter are called ___.

(j) Asteroids are found between the orbits of ___ and ___.

(k) Shooting stars are actually not ___.

(l) A celestial body that revolves around a planet is known as ___.

(m) A meteoroid becomes a ___ on entering Earth's atmosphere.

(n) The long distance transmission of television programmes has been made possible with the help of ___ satellites.

Q. Which of the following is NOT a planet of the sun?

1. Sirius
2. Mercury
3. Saturn
4. Earth

Q.

The planets keep changing their position with respect to stars.

1. True
2. False

Q. is the second nearest star to us, at a distance of.

1. Betelgeuse
2. $4.24\text{ly}$
3. Proxima Centauri
4. $2.42\text{ly}$

Q. What happens to the stars during the daytime?

Q. Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth? [3 MARKS]

Q.

One light year is the distance travelled by light in

1. one year

2. one month

3. one second

4. one day

Q.

Statement 1: Stars twinkle but planets do not. Statement 2: Stars have their own light but a planet does not.

Q. Explain how artificial satellites help in transmission of television programmes over large areas.

Q.

What is the scientific name of a shooting star?

1. Asteroid

2. Comet

3. Meteor

4. Satellite

Q. The star that lies close to the axis of rotation of earth is:

Q. Why Sirius is a brightest star in sky ?

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Q. Two small dense stars rotate about their common centre of mass as a binary system with the period 1 year for each.One star is of double the mass of the other and the mass of the lighter one is one third of the mass of the sun.Find the distance between the stars if the distance between thecearth and sun is R.

Q.

What is a quasar?