I. Choose the correct answer.
1. Who proposed the heliocentric model of the universe?
(a) Tycho Brahe
(b) Nicolaus Copernicus
[Answer: (b) Nicolaus Copernicus]
2. Which of the following is not a part of outer solar system?
[Answer: (a) Mercury]
3. Ceres is a ――― .
[Answer: (d) Asteroid]
4. The period of revolution of planet A around the Sun is 8 times that of planet B, How many times is the distance of planet A as great as that of planet B?
[Answer: (a) 4]
5. The Big Bang occurred ――― years ago.
(a) 13.7 billion
(b) 15 million
(c) 15 billion
(d) 20 million
[Answer: (a) 13.7 billion]
II. Fill in the blanks :
1. The speed of Sun in km/s is 250 km/s .
2. The rotational period of the Sun near its poles is 36 days.
3. India’s first satellite is Aryabhatta.
4. The third law of Kepler is also known as the Law of Harmonics.
5. The number of planets in our Solar System is 8.
III. State whether true or false. If false, correct the statement:
1. ISS is a proof for international cooperation.
2. Halley’s comet appears after nearly 67 hours.
Correct statement: Halley's comet appears after nearly 76 years.
3. Satellites nearer to the Earth should have lesser orbital velocity.
Correct statement: Satellites nearer to the Earth should have faster orbital velocity.
4. Mars is called the red planet.