Imp Questions For All Chapters – Geography Class 7
The Sun, the Moon and the Earth
Short Questions
1. What causes day and night on earth?
Answer: The rotation of the earth on its axis causes day and night.
2. What is a lunar eclipse?
Answer: A lunar eclipse occurs when the earth comes between the sun and the moon, blocking sunlight from reaching the moon.
3. On which day does a solar eclipse occur?
Answer: A solar eclipse occurs only on a new moon day.
4. Why don’t eclipses happen every full moon and new moon day?
Answer: Because the moon’s orbit is tilted by about 5° relative to the earth’s orbit.
5. What is the maximum duration of a total lunar eclipse?
Answer: The maximum duration of a total lunar eclipse is 107 minutes.
6. What is an annular solar eclipse?
Answer: It occurs when the moon is too far to cover the entire sun, leaving a bright ring visible.
7. What is the difference between perigee and apogee?
Answer: Perigee is when the moon is closest to the earth, and apogee is when it is farthest.
8. How can we safely observe a solar eclipse?
Answer: By using solar filters, eclipse glasses, or the pinhole projection method.
9. Which sequence of celestial bodies causes a lunar eclipse?
Answer: The sequence is Sun → Earth → Moon.
10. What is the main reason behind superstitions related to eclipses?
Answer: Lack of scientific awareness and myths passed through generations.
Long Questions
1. What are the phases of the moon, and why do they occur?
Answer: The moon has different phases such as new moon, first quarter, full moon, and last quarter due to its changing position relative to the earth and the sun. These phases occur because the moon reflects the sunlight, and the visible portion varies as it orbits the earth.
2. How does a total solar eclipse occur?
Answer: A total solar eclipse happens when the moon completely covers the sun’s disk, casting a shadow on the earth. It occurs only in certain regions where the moon’s umbra (darkest shadow) falls.
3. Why does a partial solar eclipse occur along with a total solar eclipse?
Answer: A partial solar eclipse occurs in areas outside the total eclipse region, where the moon only partially covers the sun. This happens because the moon’s penumbral (outer) shadow covers a larger area than its umbra.
4. What precautions should be taken while observing a solar eclipse?
Answer: One should never look at a solar eclipse directly, as it can damage eyesight. Safe methods like using eclipse glasses, solar filters, or indirect projection techniques should be used to view the eclipse safely.
5. What is the difference between a solar and lunar eclipse?
Answer: A solar eclipse occurs when the moon comes between the sun and the earth, blocking sunlight from reaching the earth. A lunar eclipse happens when the earth comes between the sun and the moon, blocking sunlight from reaching the moon.
6. Why do we see different types of solar eclipses?
Answer: The type of solar eclipse depends on the moon’s distance from the earth. A total eclipse occurs at perigee when the moon appears larger, while an annular eclipse occurs at apogee when the moon appears smaller than the sun.
7. How can we eliminate superstitions related to eclipses?
Answer: Superstitions can be eliminated through education, awareness campaigns, and encouraging scientific observation of eclipses. Schools, media, and space organizations can play a role in spreading knowledge about these natural phenomena.
8. Why does the moon appear larger at perigee and smaller at apogee?
Answer: Since the moon’s orbit is elliptical, it is closer to the earth at perigee, making it appear larger. At apogee, it is farther from the earth, making it appear smaller in size.
9. Why does the moon not produce its own light?
Answer: The moon does not have its own light; it shines by reflecting the sunlight. The amount of sunlight reflected toward the earth determines the moon’s visible phase.
10. What is the role of nodes in the occurrence of eclipses?
Answer: Eclipses occur only when the sun, moon, and earth align at the nodes, which are the two points where the moon’s tilted orbit intersects the earth’s orbit. This alignment is necessary for an eclipse to take place.
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