Let Us Exercise
1. Choose the appropriate option
a Read the statements given below and identify the ones that relate to Uranus
i. It is the second-largest planet
ii. It is an ice giant.
iii. It rotates from east to west
IV. It rotates on its side
Only 1 II. Only II and III. iii. Only lI, III, and IV. All I, II, III and IV
Answer.iii. Only II, III, and IV
- Uranus is the third-largest planet (not second).
- It is an ice giant, rotates sideways (98° tilt), and spins retrograde (east to west).
b. Asteroids are found between the orbits of which two planets?
i. Earth and Mars ii. Saturn and Jupiter
iii. Mars and Jupiter iv. Mars and Venus
Answer. iii. Mars and Jupiter
c. If you observe the night sky closely, you will observe groups of stars forming recognisable patterns. Identify the one given
below.
i. Orion ii. Ursa Major
iii. Canis Major iv. Leo
Answer .i. Orion
2. Assertion/Reason
In the question given below, there are two statements marked as Assertion (A) and Reason
Read the statements and choose the correct option:
a. Assertion (A)- Asteroids are known as minor planets.
Reason (R)- They are the same size as that of the other planets.
i Both A and R are true, and R is the correct explanation of A
ii. Both A and R are true, but R is not the correct explanation of A
iii. If A is true but R is false
iv. If A is false but R is true
Answer: iii. A is true but R is false
- Asteroids are small rocky bodies, much smaller than planets.
b. Assertion (A)-Mercury is the hottest planet in our solar system.
Reason (R)-It is nearest to the Sun
i. Both A and R are true, and R is the correct explanation of A
ii. Both A and R are true, but R is not the correct explanation of A
iii. If A is true but R is false
iv. If A is false but R is true
Answer. iv. A is false but R is true
Q3.Answer the following questions in 10 to 20 words
a. What is a galaxy?
Answer. A galaxy is a huge system of stars, gas, dust, and dark matter bound by gravity (e.g., Milky Way).
b. What is a solar system?
Answer. A solar system consists of a star (Sun) and celestial bodies (planets, moons, asteroids) orbiting it.
c. Name all the eight planets as per their distance from the sun.
- Answer. Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
4. Answer the following question in 50 to 70 words
a. What are the different phases of the moon? Explain with the help of a diagram.
b. What do you mean by a solar eclipse? Explain with the help of a well-labelled diagram.
c. Earth is the only planet that humans know has life. Elucidate the statement by explaining the favourable conditions that support life on Earth.
- Answer. Liquid water,
- Oxygen-rich atmosphere,
- Right temperature range (not too hot/cold),
- Protective magnetic field,
- Stable climate and seasons.
No other planet in our solar system has all these conditions.