If the equatorial plane of earth is NOT inclined to its orbit, then
- A.duration of the year would be longer
- B.summer would be warmer
- C.there would be no change of seasons
- D.winter would be longer
Correct answer
Explanation
The correct answer is C, there would be no change of seasons. Seasons happen only because the Earth's axis is tilted to the plane of its orbit.
The Earth's equatorial plane is inclined at about 23.5 degrees to the plane of its orbit, so its axis makes an angle of about 66.5 degrees with that plane. Because of this tilt, the northern and southern hemispheres lean towards the Sun by turns as the Earth goes round it. The hemisphere leaning towards the Sun gets more direct rays and longer days, which is summer, while the other has winter. If there were no tilt, the Sun would always be overhead at the equator, day and night would be equal everywhere throughout the year, and each place would have the same weather pattern all year.
A is wrong: the length of the year depends on the time the Earth takes to go round the Sun, not on the tilt.
B is wrong: without the tilt there would be no summer season at all.
D is wrong: without the tilt there would be no winter season either.
Exam tip: Axis tilt 23.5 degrees to the vertical (66.5 degrees to the orbital plane) causes seasons and unequal day and night; revolution decides the year.
Practice Questions
View allD performs her train journey by the shortest route from Bengaluru to New Delhi. Which one of the following rivers will she not cross while performing the journey?
- A.Narmada
- B.Yamuna
- C.Godavari
- D.Krishna
Show answer
The shortest rail route from Bengaluru reaches Delhi from the south through Agra and Mathura, which lie on the western side of the Yamuna, so the train never has to cross that river.
Read the full explanation →In India, the period of steady population growth refers to the decade(s) of:
- A.1981-2011
- B.1951-1981
- C.1921-1951
- D.1911-1921
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In the standard division of India's population history, the three decades from 1921 to 1951 are called the period of steady population growth.
Read the full explanation →Consider the following statements with reference to earthquakes:
1. Collapse earthquakes are most common.
2. Tsunamis are waves generated by the tremors and not an earthquake in itself.
3. High magnitude earthquakes i.e. 8+ are quite rare whereas 'tiny' types occur almost every minute.
Which of the statements given above are correct?
- A.1 and 2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
Show answer
Statement 1 is false because tectonic earthquakes, not collapse earthquakes, are the most common type. Earthquakes are grouped by cause: tectonic (sliding of rocks along a fault), volcanic, collapse (the roofs of underground mines or caverns falling in), explosion (from nuclear or chemical blasts) and reservoir-induced.
Read the full explanation →With reference to earthquakes, which of the following statements are correct?
1. Earthquakes largely occur along the converging plate boundaries.
2. Point of origin of earthquake in lithosphere is known as focus/hypocentre.
3. Intensity of earthquake decreases with distance from the epicentre.
4. Epicentre of earthquake always remains over continents only.
Select the correct answer using the code given below.
- A.1 and 2 only
- B.1, 2 and 3
- C.2 and 3 only
- D.1 and 4
Show answer
The first three statements are true, while statement 4 is false because many earthquakes have their epicentre under the sea.
Read the full explanation →National Disaster Management Authority is headed by
- A.the Prime Minister.
- B.the Home Minister.
- C.the President.
- D.the Health Minister.
Show answer
Under the Disaster Management Act, 2005, the Prime Minister is the ex officio chairperson of the National Disaster Management Authority (NDMA).
Read the full explanation →