Welcome to Bodhiclasses – your trusted guide for meaningful, simplified, and insightful learning. In this post, we bring you a comprehensive set of solved questions from Chapter 12 of Class 7 Science – Earth, Moon, and the Sun. These solved questions are from the NCERT textbook “Let Us Enhance Our Learning” section, and are perfect for revision, homework help, or exam preparation.
1. In Fig. 12.17, how many hours of sunlight do the North Pole and the South Pole receive during one rotation of the Earth?
Answer:
- The North Pole receives sunlight for 24 hours.
- The South Pole remains in darkness for 24 hours.
2. Fill in the blanks
(i) Stars rise in the east and set in the west.
(ii) Day and night are caused by the Earth’s rotation.
(iii) When the Moon fully covers the Sun from our view, it is called a total solar eclipse.
Chapter 12 of Class 7 Science – Earth, Moon, and the Sun
3. State whether True or False
(i) Lunar eclipse occurs when the Sun comes between the Earth and the Moon. – False
(ii) Sunrise happens earlier in Gujarat than in Jharkhand. – False
(iii) In Chennai, the longest day occurs on the summer solstice. – True
(iv) We should watch the solar eclipse directly with our naked eye. – False
(v) Seasons occur due to the tilt of Earth’s axis of rotation and its spherical shape. – True
(vi) The Earth’s revolution around the Sun causes day and night. – False
4. Padmashree saw the Orion constellation nearly overhead at 8 pm yesterday. When will she see Orion overhead today?
Answer:
She will see Orion a few minutes earlier, around 7:56 pm today, as stars appear to rise 4 minutes earlier each night.
5. Nandhini saw a group of stars rising at midnight on 21 June. When will she see the same group of stars rising at midnight next year?
Answer:
She will see the same group of stars rising at midnight on 21 June next year, exactly one year later.
6. Abhay noticed that when it was daytime in India, his uncle who was in the USA was generally sleeping as it was night-time there. What is the reason behind this difference?
Answer:
The difference is due to the rotation of the Earth, which causes day and night at different places on Earth at the same time.
Chapter 12 of Class 7 Science – Earth, Moon, and the Sun
7. Four friends used the following ways to see the solar eclipse. Who among them was being careless?
(i) Ravikiran used a solar eclipse goggle.
(ii) Jyothi used a mirror to project the Sun’s image.
(iii) Adithya saw the Sun directly with his eyes.
(iv) Aruna attended a programme arranged by a planetarium.
Answer:
Adithya was being careless. Looking at the Sun directly with the eyes during an eclipse can damage eyesight.
8. Fill in the circles in Fig. 12.18 appropriately with one of the following: Sun, Moon, Earth.
Answer:
- Solar Eclipse:
Left circle – Sun
Middle circle – Moon
Right circle – Earth - Lunar Eclipse:
Left circle – Sun
Middle circle – Earth
Right circle – Moon
9. The Moon is much smaller than the Sun, yet it can block the Sun completely from our view during a total solar eclipse. Why is it possible?
Answer:
This happens because the Moon is much closer to the Earth than the Sun. Despite being smaller, its apparent size in the sky is almost equal to the Sun, so it can completely cover the Sun during a total solar eclipse.
10. The Indian cricket team matches in Australia are often held in December. Should they pack winter or summer clothes for their trip?
Answer:
They should pack summer clothes, because December is summer season in the Southern Hemisphere, where Australia is located.
11. Why do you think lunar eclipses can be seen from a large part of the Earth when they happen, but total solar eclipse can be seen by only a small part of the Earth?
Answer:
The Earth’s shadow during a lunar eclipse is much larger than the Moon’s shadow during a solar eclipse. So, lunar eclipses are visible from a large area, while solar eclipses are visible only from a narrow path where the Moon’s shadow falls.
Chapter 12 of Class 7 Science – Earth, Moon, and the Sun
12. If the Earth’s axis were not tilted with respect to the axis of revolution, explain what would be the effect on seasons?
Answer:
If the Earth’s axis were not tilted, there would be no seasons. Every place on Earth would receive equal sunlight throughout the year, and the variation in day length and temperature that causes seasons would not occur.
