The occurrence of seasons on the Earth is caused mainly by which of the following?
- A.The changing distance between the Earth and the Sun
- B.The rotation of the Earth on its axis
- C.The tilt of the Earth's axis along with its revolution around the Sun
- D.The gravitational pull of the Moon
Correct answer
Explanation
The correct answer is C. The axis of the Earth is tilted about 23.5 degrees from the vertical and keeps pointing in the same direction throughout the year. As the Earth revolves, each hemisphere is therefore turned towards the Sun for part of the year, receiving more direct rays and longer days, and away from it for the other part, which gives summer and winter.
Option A is the commonest trap. The Earth is actually closest to the Sun in early January, when the northern hemisphere has winter, so distance cannot explain the seasons. Option B, rotation, causes day and night, not the seasons. Option D, the pull of the Moon, is the main cause of tides in the oceans. A useful way to remember it: rotation gives day and night, revolution with tilt gives the seasons and the year.
Read the full article: Solar System and the Earth: Planets, Moon and Motions
Practice Questions
View allWhich is the hottest planet of the solar system?
- A.Mercury
- B.Venus
- C.Mars
- D.Jupiter
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Venus is wrapped in a very thick atmosphere of carbon dioxide, which lets sunlight in but does not let the heat escape.
Read the full explanation →Approximately how long does sunlight take to reach the Earth?
- A.8 minutes 20 seconds
- B.1.3 seconds
- C.4.2 years
- D.24 hours
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The Sun is about 149.6 million kilometres from the Earth, a distance called one astronomical unit, and light travels about three lakh kilometres in a second.
Read the full explanation →Which is the largest planet of the solar system?
- A.Saturn
- B.Neptune
- C.Jupiter
- D.Uranus
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Jupiter is the fifth planet from the Sun and the largest of all by both diameter and mass; it is a gas giant of hydrogen and helium.
Read the full explanation →Apart from Uranus, which planet rotates on its axis from east to west, that is in a direction opposite to most planets?
- A.Mercury
- B.Venus
- C.Mars
- D.Saturn
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Almost every planet, the Earth included, rotates from west to east, which is why the Sun appears to rise in the east.
Read the full explanation →Which planet has the lowest density, so low that it would float if placed in a large enough body of water?
- A.Jupiter
- B.Saturn
- C.Neptune
- D.Mercury
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Saturn is a huge ball of hydrogen and helium spread over an enormous volume, and its average density is less than that of water.
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