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Q1. Which of the following was the first satellite launched by India?

• 1) Aryabhatta
• 2) EDUSAT
• 3) Kalpana-1
• 4) INSAT

Solution

Aryabhatta was the first satellite launched by India.

Q2. Which of the following celestial objects separates the inner and outer planets of the solar system?

• 1) Meteor
• 2) Asteroid
• 3) Meteorite
• 4) Comet

Solution

Asteroid separates the inner and outer planets of the solar system in the form of the asteroid belt.

Q3. How many constellations are officially recognized by the International Astronomical Union (IAU)?

• 1) 108
• 2) 76
• 3) 88
• 4) 58

Solution

88 constellations are officially recognized by the International Astronomical Union (IAU).

Q4. Artificial satellites can be used to predict earthquakes.

• 1) True
• 2) False

Solution

Artificial satellites are used for weather forecasting, long distance communication and remote sensing.

Q5. The given diagram shows four positions of the moon in its orbit around the Earth. The full moon phase is represented by the position labelled

• 1) III
• 2) IV
• 3) I
• 4) II

Solution

On a full moon day, the full disc of the moon is visible and this happens when Moon is opposite to the Sun, i.e. in position IV.

Q6. What is a meteorite? How does it help the scientists?

Solution

A meteor glows and evaporates quickly as it enters earth's atmosphere. Some meteors are large and so they can reach the earth before they evaporate completely. The body that reaches the earth is called a meteorite. Meteorites help the scientists in investigating the nature of the material from which the solar system was formed.

Q7. What are artificial satellites? Name the first Indian satellite.

Solution

The man made satellites which are orbiting the earth are called artificial satellites. The first Indian satellite was Aryabhatta.

Q8. How many miles are there in a light year?

• 1) 6 trillion
• 2) 3.6 million
• 3) 10 million
• 4) 93 million

Solution

1 light year = 6 x 10¹² miles                  = 6 trillion miles

Q9. A full moon appears on Sunday. The next full moon will appear on?

• 1) Friday
• 2) Monday
• 3) Thursday
• 4) Saturday

Solution

The time period between one full moon to the next full moon is slightly longer than 29 days.

Q10. What is a constellation? Name any two constellations.

Solution

A constellation is a group of stars that can be identified with the shape of an identifiable object like an animal or a known object. The two well known constellations are Ursa Major and Orion.

Q11. There are nine planets in the Solar System.

• 1) False
• 2) True

Solution

False. There are eight planets in the Solar System. 

Q12. Some meteors are large so that they can reach the Earth before they evaporate completely. The body that reaches the Earth is called

• 1) Meteorite
• 2) Comet
• 3) Shooting star
• 4) Asteroid

Solution

Some meteors are large so that they can reach the Earth before they evaporate completely. The body that reaches the Earth is called a meteorite.

Q13. How can we locate the brightest star in the sky?

Solution

To locate Sirius, imagine a straight line passing through the three middle stars of the Orion. Look along this line towards the east and this will lead us to the brightest star, Sirius.

Q14. The Moon is the earth's only natural satellite and the ________ largest satellite in the solar system.

Solution

The Moon is the earth's only natural satellite and the fifth largest satellite in the solar system.

Q15. Which of the following characteristics of planets is a feature of Saturn?

• 1) It is the blue planet of the solar system
• 2) It is the largest planet of the solar system
• 3) Its density is less than the density of water
• 4) It has the longest period of revolution

Solution

The density of Saturn is less than the density of water.

Q16. What happens to the size of the moon after the new moon day?

Solution

The size of the illuminated part of the moon visible from the earth increases each day after the new moon day.

Q17. Moon emits its own light.

• 1) True
• 2) False

Solution

False. Moon does not produce its own light.

Q18. _____________ was the first man to land on moon.

Solution

Neil Armstrong was the first man to land on moon.

Q19. Give two differences between stars and planets.

Solution

Differences between stars and planets: 1. A star has its own light but a planet has no light of its own. It shines by reflecting the light of the sun. 2. Stars twinkle at night, while planets do not twinkle.

Q20. Why the planet 'Venus' is called the morning or an evening star?

Solution

Venus appears in the eastern sky before sunrise and sometimes it appears in the western sky just after sunset so it is called as the morning or an evening star.

Q21. Between the orbits of which two planets is the Asteroid belt found?

• 1) Mars and Jupiter
• 2) Earth and Mars
• 3) Mercury and Venus
• 4) Mercury and Earth

Solution

Asteroids are small celestial objects which revolve around the Sun between the orbits of Mars and Jupiter.

Q22. What are constellations?

• 1) Patterns in the sky
• 2) Twin stars
• 3) Group of planets
• 4) All of the above

Solution

The stars forming a group that has a recognisable shape or pattern is called a constellation.

Q23. Why do the stars appear to move from east to west?

Solution

The stars appear to move from east to west because the earth rotates on its axis from west to east.

Q24. The various shapes of the bright part of the moon seen during a month are called ________ of the moon.

Solution

The various shapes of the bright part of the moon seen during a month are called phases of the moon.

Q25. Earth's period of rotation and revolution respectively is

• 1) 24 hours, 365 days
• 2) 24 days, 365 days
• 3) 365 days, 24 hours
• 4) 365 days, 24 days

Solution

Earth's period of rotation is 24 hours and its period of revolution is 365 days.

Q26. Bright streaks of light in the sky are commonly known as ______________.

Solution

Bright streaks of light in the sky are commonly known as shooting stars.

Q27. Which two planets have asteroids between them?

Solution

Aasteroids are the rocks pieces that revolve around the sun between the orbit of Mars and Jupiter.

Q28. Explain the structure of Ursa Major.

Solution

It appears like a big ladle or a question mark. There are three stars in the handle of the ladle and four in its bowl.

Q29. Gap between consecutive New Moon day and Full Moon day is__________ days.

Solution

Gap between consecutive New Moon day and Full Moon day is 15 days.

Q30. Name the constellations which are generally seen in summers and winters, respectively.

• 1) Ursa major, Orion
• 2) Orion, Leo major
• 3) Orion, Ursa major
• 4) Ursa major, Leo major

Solution

Ursa Major is generally seen in summer whereas Orion is generally seen in winters.

Q31. On a new moon day, the moon is fully visible.

• 1) False
• 2) True

Solution

False. On a new moon day, the moon is not visible.

Q32. Why does the moon change its shape everyday?

Solution

The moon does not produce its own light so it is seen only when the sunlight reflects it. Therefore, we see only that part of the moon from which the light of the sun is reflected towards us.

Q33. __________ is also called the hunter.

Solution

Orion is also called the hunter.

Q34. The huge distances between the earth and other celestial bodies are measured in __________. 

Solution

The huge distances between the earth and other celestial bodies are measured in light years. 

Q35. What are the uses of artificial satellites?

• 1) For long distance communication
• 2) For weather forecasting
• 3) All of the above
• 4) For remote sensing

Solution

Artificial satellites are used for weather forecasting, remote sensing and long distance communication.

Q36. Ursa Major constellation is also called ____________.

Solution

Ursa Major constellation is also called Saptarishi.

Q37. What is a comet? How does it appear?

Solution

A comet is a member of solar system which revolves around the sun in highly elliptical orbits. It appears as bright head with a long tail.

Q38. The solar system consists of ________ planets.

Solution

The solar system consists of eight planets.

Q39. Which is the planet nearest to the Sun? Why is it difficult to observe it?

Solution

Mercury is the nearest planet to the sun. It is difficult to observe it as most of the time it is hidden in the glare of the sun.

Q40. The size of the bright part of the moon appears to become thinner and thinner after the __________.

Solution

The size of the bright part of the moon appears to become thinner and thinner after the full moon day.