Question 1.
Which of the following is NOT a member of the solar system?
(a) An asteroid
(b) A satellite
(c) A constellation
(d) A comet
(c) A constellation
Question 2.
Which of the following is NOT a planet of the sun?
(a) Sirius
(b) Mercury
(c) Saturn
(d) Earth
(a) Sirius
Question 3.
Phases of the moon occur because
(a) we can see only that part of the moon which reflects light towards us.
(b) our distance from the moon keeps changing.
(c) the shadow of the Earth covers only a part of the moon’s surface.
(d) the thickness of the moon’s atmosphere is not constant.
(a) we can see only that part of the moon which reflects light towards us
Question 4.
Fill in the blanks.
(a) The planet which is farthest from the Sun is _____
(b) The planet which appears reddish in colour is ______
(c) A group of stars that appear to form a pattern in the sky is known as a _____
(d) A celestial body that revolves around a planet is known as ______
(e) Shooting stars are actually not _____
(f) Asteroids are found between the orbits of and ______
(a) Neptune
(b) Mars
(c) constellation
(d) satellite
(e) stars
(f) Mars, Jupiter
Question 5.
Mark the following statements as true (T) or false (F).
(a) Pole star is a member of the solar system.
(b) Mercury is the smallest planet of the solar system.
(c) Uranus is the farthest planet in the solar system.
(d) INSAT is an artificial satellite.
(e) There are nine planets in the solar system.
(f) Constellation Orion can be seen only with a telescope.
(a) False
(b) True
(c) False
(d) True
(e) False
(f) False
Question 6.
Match items in column A with one or more items in column B.
(i) (e) (g)
(ii) (a)
(iii) (c) (f)
(iv) (d)
Question 7.
In which part of the sky can you find Venus if it is visible as an evening star?
In west side of the sky.
Question 8.
Name the largest planet of the solar system.
Jupiter
Question 9.
What is a constellation? Name any two constellations.
A group of stars which has a recognizable shape is called a constellation.
Example: Ursa Major, Orion
Question 10.
Draw sketches to show the relative positions of prominent stars in
(i) Ursa Major and
(ii) Orion
(i) Ursa Major
(ii) Orion
Question 11.
Name two objects other than planets which are members of the solar system.
Comets and asteroids.
Question 12.
Explain how you can locate the Pole star with the help of Ursa Major.
Pole star can be located with the help of two stars at the end of Ursa Major. Imagine a straight line passing through these stars. Extend the imaginary line in North direction. This line is about five times the distance between two stars. A star is seen in this direction which is called Pole star.
Question 13.
Do all the stars in the sky move? Explain.
No, all the stars do not move in the sky. Due to the rotation of the Earth on its own axis stars seem to move in the sky.
Question 14.
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?
The stars are very far away from the Earth and it is not convenient to express such distances in kilometres. Thus, such large distances are expressed in unit known as light year.
If we say that a star is eight light years away from Earth, it means that the light from star will reach the Earth in eight years.
Question 15.
The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accommodate?
Question 16.
Boojho made the following sketch (Fig. 17.6) of the solar system. Is the sketch correct or not, correct it.
No, the sketch made by Boojho is not correct. The correct sketch is given below:
Question 17.
Name the instrument you will use to observe rings of the planet Saturn.
Telescope.
Question 18.
Which star appears to remain fixed to us ? What is / are the name/s given to it ?
Pole star appears to be fixed. Its name is Dhruv Tara.
Question 19.
Planet ………….. is known to have the largest number of natural satellites.
Jupiter.
Question 20.
Name any two constellations that have seven prominent stars in them.
Ursa Major and Ursa Minor have seven prominent stars in them.
Question 21.
Name the planet that was predicted before it was actually observed.
Pluto
Question 22.
Why the stars are not visible during the day?
The stars are not visible during the day because of the glare of bright sunlight.
Question 23.
Which of the following is NOT a member of the solar system?
- An asteroid
- A satellite
- A constellation
- A comet
A satellite.
Question 24.
Which of the following is NOT a planet of the sun?
- Sirius
- Mercury
- Saturn
- Earth
Sirius.
Question 25.
Phases of the moon occur because
- we can see only that part of the moon which reflects light towards us.
- our distance from the moon keeps changing.
- the shadow of the Earth covers only a part of the moon’s surface. ’
- the thickness of the moon’s atmosphere is not constant. ‘
We can see only that part of the moon which reflects light towards us.
Question 26.
Fill in the blanks :
- The planet which is farthest from the Sim is …………
- The planet which appears reddish in colour is ……………
- A group of stars that appear to form a pattern in the sky is known as a ………….
- A celestial body that revolves around a planet is known as ……………..
- Shooting stars are actually not ……………
- Asteroids are found between the orbits of …………. and …………..
- Neptune
- Mars.
- Constellation.
- Satellite.
- Stars
- Mars, Jupiter.
Question 27.
Mark the following statements as true (T) or false (F).
- Pole star is a member of the solar system. ( )
- Mercury is the smallest planet of the solar system. ( )
- Uranus is the farthest planet in the solar system. ( )
- There are nine planets in the solar system. ( )
- INSAT is an artificial satellite. ( )
- Constellation Orion can be seen only with a telescope. ( )
- T
- T
- F
- F
- T
- F
Question 28.
Match the items in column I with one or more items in column II
| Column-I | Column-II |
| (a) Star | (i) Saturn |
| (b) Constellation | (ii) Pole star |
| (c) Planet | (iii) Great Bear |
| (d) Satellite of the earth | (iv) Moon |
| (v) Earth | |
| (vi) Orion | |
| (vii) Mars |
| Column-I | Column-II |
| (a)Star (b) Constellation (c) Planet (d) Satellite of the earth |
(i) Pole star (iii) Great Bear, (vi) Orion (iii) Saturn, (v) Earth, (vii) Mars (iv) Moon |
Question 29.
In which part of the sky can you find Venus if it is visible as an evening star ?
Venus appears in the western sky as an evening star.
Question 30.
What is full moon day ?
The day on which the whole disc of the moon is visible is known as the full moon day.
Question 31.
Can you see the back side of the moon from the earth ?
No, we cannot see the back side of the moon from the earth.
Question 32.
Does the moon have atmosphere and water ?
No, moon doesn’t have atmosphere or Water.
Question 33.
Can you hear sound on the moon ?
No, we cannot hear sound on the moon because there is no medium in which sound can travel.
Question 34.
What is an orbit ?
The path taken by planets to revolve around the sun is called an orbit.
Question 35.
Why do the planets not collide while revolving around the sun ?
Planets move in their own orbits, so they don’t collide with each other.
Question 36.
Is the earth a satellite of the sun ?
No, even though the earth revolves around the sun but it is not a satellite of the sun, because satellites revolve around the planets.
Question 37.
Why is it difficult to observe Mercury ?
Mercury is closest to the sun, so it is hidden by the glare of the sun. So, it cannot be seen.
Question 38.
Name two planets having no satellites.
Mercury and Venus.
Question 38.
What are meteor showers ?
When the earth crosses the tail of the comet, swarms of meteors are seen, known as meteor showers.
Question 39.
What is meant by remote sensing ?
Collecting information from a distance by satellites is known as remote sensing.
Question 40.
Name any three celestial bodies.
The stars, Sun and Moon are celestial bodies.
Question 41.
Why do we classify the Sim as a star ?
The Sun is a star because it continuously emits light and heat. It appears large as compared to other stars because it is nearer to the Earth.
Question 42.
Name the planets that were known to ancient astronomers.
The planets known to ancient astronomers were Mercury, Venus, Earth, Mars, Jupiter and Saturn.
Question 43.
The artificial satellites are used for ………., ……., ……….. and …………
Long distance communication, research, remote sensing and defence.
Question 44.
Which of the following is a star ?
- Alpha Centuari
- Diebos
- Orion
- Phobos
Alpha Centuari.
Question 45.
Ursa Major is
- a star
- seen only with a telescope
- a constellation
- a natural satellite of Mars
a constellation.
Question 46.
The stone like objects entering the Earth’s atmosphere appear as …………. of …………. at night and these are called …………
Streak, light, meteors.
Question 47.
A celestial body that appears to change its position with respect to the stars is called ………….
Earth.
Question 48.
Which planet is nearest to the Earth ?
Venus.
Question 49.
Name two planets which are near to the Sun.
Mercury and Venus.
Question 50.
Which planet moves in a different plane ?
Pluto.
Question 51.
What are asteroids ?
They are very small planets of rock and metal which revolve around Sun mainly between Mars and Jupiter.
Question 52.
Name the branch of science which deals with the study of the universe.
Astronomy.
Question 53.
What is the shape of the Earth ?
The Earth is not a perfect sphere, but is somewhat flattened at the poles and is bulging at the equator.
Question 54.
What is solar system ?
The sun and the nine planets along with their natural satellites constitute the solar system.