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Class 7 Science: Earth, Moon, and the Sun, 8 practice questions with answers

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These are 8 practice questions on the twelfth and last chapter of the new NCERT Class 7 Science textbook, Curiosity, called Earth, Moon, and the Sun. Each has a short answer and the textbook page it comes from. They cover the Earth's rotation, the Pole Star, how far the Earth turns in an hour, the length of a year, why June is hot in Delhi, the length of daytime, apparent size, and eclipses. For the solar system itself, see our Class 6 Beyond Earth guide. Try each question before you read the answer.

These questions are our own, drafted with AI help. Every fact was checked against the page it cites by a test script, but no practising teacher has reviewed them yet. If you find a mistake, please tell us.

What the chapter says you need

Facts from the NCERT textbook (Curiosity, Grade 7, Chapter 12, printed pages 169 to 186):

Day, night and the stars

Question 1. (a) In which direction does the Earth rotate, seen from above the North Pole? (b) About how long does one rotation take? (c) Through which two points does its axis pass? (d) Suppose the Earth spun the other way, from East to West. In which direction would the Sun then seem to rise, and where would it set?

Answer: (a) anticlockwise, from West to East; (b) about 24 hours; (c) the geographic North and South Poles; (d) it would seem to rise in the West and set in the East. (a) Seen from above the North Pole, the Earth turns anticlockwise, that is, from West to East. (b) One rotation takes about 24 hours. (c) The axis of rotation passes through the geographic North Pole and South Pole. (d) The Sun only appears to move across the sky because the Earth turns: turning towards the East, we meet the Sun on the eastern side first, so it seems to rise in the East. If the Earth turned towards the West instead, we would meet the Sun on the western side first, so it would seem to rise in the West and set in the East. (Rotation of the Earth, pages 171 to 173.)

Question 2. (a) Why does the Pole Star seem to stay almost in the same place all night, while other stars seem to move? (b) In which direction does the Moon appear to rise, and why?

Answer: (a) the Earth's axis points very close to it; (b) in the East, because the Earth turns from West to East. (a) Seen from the Northern Hemisphere, the line the Earth spins about points almost straight at the Pole Star, so the Pole Star appears nearly stationary while all the other stars appear to move around it. (b) Like the Sun, the Moon appears to rise in the East and set in the West, because the Earth turns from West to East. (Apparent motion of the stars and the Moon, page 174.)

Question 3. A place on the Earth turns once all the way round the axis, 360 degrees, in about 24 hours. (a) Through how many degrees does it turn in 1 hour? (b) In 6 hours? (c) How long does it take to turn through 45 degrees?

Answer: (a) 15 degrees; (b) 90 degrees; (c) 3 hours. (a) 360 ÷ 24 = 15 degrees each hour. (b) 6 × 15 = 90 degrees, a quarter of a turn. (c) 45 ÷ 15 = 3 hours. The chapter gives only the time for one rotation, about 24 hours; working in degrees is the maths of a full turn, beyond this chapter. (One rotation in about 24 hours, page 171.)

Question 4. One trip of the Earth around the Sun lasts roughly 365 days plus 6 hours. (a) How many extra hours build up over 4 years, beyond 4 × 365 days? (b) How many days is that?

Answer: (a) 24 hours; (b) one day. (a) Each year has 6 hours more than 365 days, so in 4 years the extra time is 4 × 6 = 24 hours. (b) 24 hours is one full day. (This is why calendars add an extra day, 29 February, every fourth year; the chapter does not cover leap years, so treat this part as extra.) (Revolution of the Earth, page 176.)

Seasons

Question 5. A torch is held straight above a table and makes a small, bright round spot. Tilted, the same torch makes a larger, dimmer spot. (a) Why is the tilted spot dimmer, when the same torch gives the same light? (b) Which spot is like the sunlight falling on Delhi in June, and which like the sunlight on Delhi in December? (c) Give one more reason the chapter gives for Delhi being hotter in June.

Answer: (a) the same light is spread over a larger area; (b) June is like the straight, small spot, December like the tilted, large one; (c) the days are longer in June. (a) The torch gives the same amount of light either way. Tilted, that light is spread over a larger area, so each part of the spot gets less, and it looks dimmer. (b) In June the northern half of the Earth leans towards the Sun, so a given amount of sunrays falls on a smaller area there and heats it more, like the straight torch. In December the same sunrays are spread over a larger area, like the tilted torch, and the area is heated less. (c) In June, places in the Northern Hemisphere also get sunlight for more than 12 hours a day, so the intense sunlight lasts longer. (The tilt, the round Earth and the seasons, pages 177 and 178.)

Question 6. (a) In June, is the daytime in Delhi more or less than 12 hours? (b) In December, is the daytime in Delhi more or less than 12 hours, and does a given amount of sunlight fall on a smaller or a larger area there than in June? (c) Why are seasons less marked in the southern states of India?

Answer: (a) more; (b) less, and a larger area; (c) they lie close to the equator. (a) In June the northern half of the Earth, where Delhi is, leans towards the Sun, and places there get sunlight for more than 12 hours of each 24-hour rotation. (b) In December the situation is the opposite: Delhi gets sunlight for less than 12 hours, and a given amount of sunrays is spread over a larger area, so it is less intense. Both make December winter in Delhi. (c) On the equator there are always about 12 hours of daylight and 12 of darkness, and the strength of sunlight changes little through the year, so places near it, such as the southern states of India, do not feel the seasons very strongly. (Daytime and spreading of sunlight in June and December, pages 177 and 178; the equator, page 179.)

Eclipses

Question 7. Two identical street lamps stand on a long straight road, one 10 metres from you and the other 100 metres away. (a) Which one is bigger in real size? (b) Which one looks bigger to you, and why? (c) At night, a bus drives away from you down the road. What happens to how big its rear lights look, and does their real size change?

Answer: (a) neither, they are the same size; (b) the nearer lamp; (c) they look smaller and smaller, but their real size does not change. (a) The lamps are identical, so their real sizes are the same. (b) How big a thing looks, its apparent size, depends on both its actual size and its distance from you. With equal real sizes, the nearer lamp looks bigger. (c) As the bus moves away, the actual size of its rear lights stays the same, but their distance from you grows, so their apparent size shrinks: they look smaller and smaller until they are tiny dots. (Apparent size, page 180.)

Question 8. (a) What colour does the Moon look during a total lunar eclipse? (b) Is it safe to watch a lunar eclipse with the naked eye? (c) Why does a total solar eclipse last only a few minutes at any one place?

Answer: (a) dark red; (b) yes; (c) the Moon's shadow moves across the Earth. (a) When the Moon is completely inside the Earth's shadow, its bright disc turns dark red until it moves out. (b) The eclipsed Moon can be watched safely with the naked eye (unlike the Sun, which must never be viewed directly, even during a solar eclipse). (c) Because the Earth rotates and the Moon moves along its orbit, the Moon's shadow sweeps across the Earth's surface, so any one place is in total darkness for only a few minutes. (Solar eclipse, page 181; lunar eclipse, page 183.)

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Sources

All opened and read on 2 November 2026. Page numbers are the printed page numbers of the textbook; printed page = PDF page + 168 for this chapter.

The facts are from the textbook pages above. The questions, answers and checks are our own. This guide is general information; follow your teacher and the textbook.