CBSE Class 6 General Knowledge

Unit 4: Science & Technology

Lesson: Earth – Rotation and Revolution

📘 Study Module: Earth – Rotation and Revolution

1. Introduction

The Earth is constantly moving in space. It performs two main movements known as rotation and revolution. These movements are responsible for important natural phenomena such as day and night and change of seasons.

2. Rotation of the Earth

Rotation is the movement of the Earth on its own axis. The Earth takes about 24 hours to complete one rotation. This movement causes day and night.

3. Effects of Rotation

Due to rotation, the side of the Earth facing the Sun experiences day, while the opposite side experiences night. Rotation also causes the apparent movement of the Sun from east to west.

4. Revolution of the Earth

Revolution is the movement of the Earth around the Sun in a fixed path called an orbit. The Earth takes about 365¼ days to complete one revolution.

5. Effects of Revolution

Revolution causes the change of seasons. It also leads to variation in the length of days and nights throughout the year. Leap years occur due to the extra one-fourth day.

6. Difference Between Rotation and Revolution

Rotation is a daily movement causing day and night, while revolution is a yearly movement causing seasons. Both movements are essential for life on Earth.

📝 Questions and Answers

A. Short Answer Questions

(One sentence each)

1. What is rotation of the Earth?
   Answer: Rotation is the movement of the Earth on its own axis.
2. How long does Earth take to complete one rotation?
   Answer: Earth takes about 24 hours to complete one rotation.
3. What does Earth’s rotation cause?
   Answer: Earth’s rotation causes day and night.
4. What is revolution of the Earth?
   Answer: Revolution is the movement of the Earth around the Sun.
5. How long does Earth take to complete one revolution?
   Answer: Earth takes about 365¼ days to complete one revolution.
6. What is the path of Earth’s revolution called?
   Answer: The path is called an orbit.
7. Which movement causes day and night?
   Answer: Rotation causes day and night.
8. Which movement causes change of seasons?
   Answer: Revolution causes change of seasons.
9. What is a leap year?
   Answer: A leap year is a year with 366 days.
10. Why does a leap year occur?
    Answer: A leap year occurs due to the extra one-fourth day each year.

B. Long Answer Questions

(3–5 sentences each)

11. Explain the rotation of the Earth.
    Answer: Rotation is the spinning of the Earth on its axis. It takes about 24 hours to complete one rotation. This movement causes day and night. When one part of the Earth faces the Sun, it is day, while the opposite side experiences night.
12. Describe the effects of Earth’s rotation.
    Answer: Earth’s rotation causes day and night. It also results in the apparent movement of the Sun across the sky. Rotation helps maintain a balance in temperature. Without rotation, one side would be extremely hot and the other very cold.
13. Explain the revolution of the Earth.
    Answer: Revolution is the movement of the Earth around the Sun. The Earth takes about 365¼ days to complete one revolution. This movement occurs along a fixed path called an orbit. Revolution leads to the change of seasons.
14. What are the effects of Earth’s revolution?
    Answer: Earth’s revolution causes seasons. It also results in varying lengths of day and night. The extra one-fourth day each year leads to a leap year. Revolution is essential for climate changes.
15. Differentiate between rotation and revolution.
    Answer: Rotation is the movement of the Earth on its axis and takes 24 hours. Revolution is the movement of the Earth around the Sun and takes 365¼ days. Rotation causes day and night, while revolution causes seasons. Both are different but important movements.
16. Why do we experience seasons on Earth?
    Answer: Seasons occur due to Earth’s revolution around the Sun. The tilt of Earth’s axis also affects seasons. Different parts of Earth receive varying amounts of sunlight. This leads to seasonal changes.
17. What is the importance of rotation for life on Earth?
    Answer: Rotation causes regular cycles of day and night. This allows living beings to follow natural routines. It helps maintain temperature balance. Life on Earth depends on this balance.
18. What is a leap year and why is it important?
    Answer: A leap year has 366 days. It occurs every four years. The extra day adjusts the calendar with Earth’s revolution time. This keeps seasons aligned with months.
19. How does revolution affect the length of days and nights?
    Answer: During revolution, Earth’s position changes. Some regions receive more sunlight while others receive less. This causes longer days or nights. This variation changes with seasons.
20. Why are Earth’s movements important?
    Answer: Earth’s movements control day, night, and seasons. They regulate climate and life cycles. These movements make Earth suitable for life. Without them, life would be difficult.

🧠 Multiple Choice Questions (MCQs)

(With Answers and Detailed Explanations)

1. Rotation is the movement of Earth on its ______.
   a) orbit
   b) axis
   c) path
   d) surface
   Answer: b) axis
   Explanation: Rotation means spinning on its axis.
2. How long does Earth take to rotate once?
   a) 12 hours
   b) 24 hours
   c) 30 hours
   d) 365 days
   Answer: b) 24 hours
   Explanation: One rotation takes 24 hours.
3. Which movement causes day and night?
   a) Revolution
   b) Rotation
   c) Orbit
   d) Tilt
   Answer: b) Rotation
   Explanation: Rotation causes day and night.
4. Revolution is the movement of Earth around the ______.
   a) Moon
   b) Axis
   c) Sun
   d) Stars
   Answer: c) Sun
   Explanation: Earth revolves around the Sun.
5. How long does Earth take to complete one revolution?
   a) 24 hours
   b) 30 days
   c) 365¼ days
   d) 360 days
   Answer: c) 365¼ days
   Explanation: Earth takes 365¼ days to revolve.
6. What causes seasons?
   a) Rotation
   b) Revolution
   c) Day
   d) Night
   Answer: b) Revolution
   Explanation: Revolution causes seasons.
7. The path of Earth around the Sun is called ______.
   a) axis
   b) circle
   c) orbit
   d) sphere
   Answer: c) orbit
   Explanation: Earth moves in an orbit.
8. Which year has 366 days?
   a) Solar year
   b) Normal year
   c) Leap year
   d) Lunar year
   Answer: c) Leap year
   Explanation: Leap year has 366 days.
9. A leap year occurs every ______ years.
   a) two
   b) three
   c) four
   d) five
   Answer: c) four
   Explanation: Extra quarter days add up every four years.
10. Which movement affects climate?
    a) Rotation only
    b) Revolution only
    c) Both rotation and revolution
    d) Neither
    Answer: c) Both rotation and revolution
    Explanation: Both movements influence climate.
11. Which side of Earth experiences day?
    a) Side facing away from Sun
    b) Side facing the Sun
    c) Both sides
    d) Neither side
    Answer: b) Side facing the Sun
    Explanation: Sun-facing side has day.
12. Earth rotates from ______.
    a) east to west
    b) west to east
    c) north to south
    d) south to north
    Answer: b) west to east
    Explanation: Earth rotates west to east.
13. Which movement is completed in one day?
    a) Revolution
    b) Rotation
    c) Orbit
    d) Season
    Answer: b) Rotation
    Explanation: Rotation takes 24 hours.
14. Which movement is completed in one year?
    a) Rotation
    b) Revolution
    c) Day
    d) Night
    Answer: b) Revolution
    Explanation: Revolution takes one year.
15. Earth’s rotation causes ______.
    a) seasons
    b) leap year
    c) day and night
    d) orbit
    Answer: c) day and night
    Explanation: Rotation leads to day and night.
16. The extra one-fourth day is added to ______.
    a) every year
    b) every month
    c) every four years
    d) every decade
    Answer: c) every four years
    Explanation: It forms a leap year.
17. Without rotation, Earth would have ______.
    a) no gravity
    b) no seasons
    c) no day and night
    d) no orbit
    Answer: c) no day and night
    Explanation: Rotation causes day and night.
18. Which movement helps maintain temperature balance?
    a) Revolution
    b) Rotation
    c) Orbit
    d) Tilt
    Answer: b) Rotation
    Explanation: Rotation prevents extreme temperatures.
19. Earth’s revolution helps determine ______.
    a) hours
    b) minutes
    c) seasons
    d) seconds
    Answer: c) seasons
    Explanation: Seasons depend on revolution.
20. Earth’s movements make life ______.
    a) impossible
    b) difficult
    c) balanced
    d) meaningless
    Answer: c) balanced
    Explanation: Movements create suitable living conditions.

✅ End of Lesson

Prepared strictly in accordance with the NCERT syllabus and CBSE Class 6 examination standards.