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Geography & Environment · Physical Geography

Universe, Solar System & Earth Motions: 64 previous year questions

UPSC has asked 64 questions on Universe, Solar System & Earth Motions between 1997 and 2026: CSE 22 · CDS 15 · NDA 11 · CAPF 11 · Geo-Scientist 4 · CISF (LDCE) 1. 42 of them came after 2015, so this is a live topic examiners keep returning to. 22 were set in Civil Services Prelims; the rest come from UPSC's other papers, which draw on the same question bank.

Practise these 64, one at a timeRead the questions

Tap an option to check yourself. Answers follow the official UPSC key; where the key was dropped or disputed the question is not shown.

Which of the following pairs of theories about origin of the Earth and their propounders is/are correctly matched? 1. Gaseous Hypothesis : Kant 2. Binary Star Hypothesis : Russell 3. Planetesimal Hypothesis : Chamberlin Select the answer using the codes given below:

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Answer D (official UPSC key)Gaseous Hypothesis - Kant, Binary Star Hypothesis - Russell and Planetesimal Hypothesis - Chamberlin are all correctly matched

Consider the following statements in case of terrestrial planets : I. Mercury, Venus, Earth and Mars are terrestrial planets having low densities as compared to other planets. II. They lie between the Sun and the belt of asteroids. III. Their lower gravity can hold the escaping gases. Which of the statements given above is/are correct?

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Answer D (official UPSC key)Terrestrial planets lie between the Sun and the asteroid belt; they are dense and their lower gravity cannot hold escaping gases

Consider the following statements: Statement I: Scientific studies suggest that a Shift taking place in the Earth's rotation and axis. Statement II: Solar flares and associated coronal mass ejections bombarded the Earth's outermost atmosphere with tremendous amount of energy. Statement III: As the Earth's polar ice melts, the water tends to move towards the equator. Which one of the following is correct in respect of the above statements?

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Answer B (official UPSC key)Melting polar ice moves water towards the equator and shifts the Earth's rotation and axis; solar flares and coronal mass ejections occur but do not explain the shift

Which one of the following statements about the solstices, an event that occurs when the Sun appears to reach most northerly or southerly, is correct ?

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Answer C (official UPSC key)The summer solstice in the northern hemisphere occurs on June 21

Which one of the following statements with reference to the Nebular Hypothesis for the origin of Solar System is correct ?

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Answer D (official UPSC key)In the Nebular Hypothesis the material in the rings condenses to form planets revolving around the Sun

Consider the following statements about some planets in the solar system : 1. Mercury has no atmosphere. 2. Venus has two moons. 3. There is no land on Jupiter. 4. Rings of Saturn are composed of lumps of ice and dust. Which of the statements given above are correct ?

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Answer D (official UPSC key)Mercury has practically no atmosphere, Jupiter has no land surface and Saturn's rings are lumps of ice and dust; Venus has no moons

In a group discussion on shape and size of the Earth, three students stated the following points : 1. Student 1 : The shape of the Earth is basically an oblate spheroid. 2. Student 2 : The polar diameter of the Earth is more than the equatorial diameter. 3. Student 3 : Bulge along the equatorial region is due to revolution of the Earth. Who among the above students is/are correct?

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Answer A (official UPSC key)The Earth is an oblate spheroid; its polar diameter is less than the equatorial diameter and the equatorial bulge is due to rotation, not revolution

Inhabitants are unaware of the speed of rotation of the planet Earth because 1. the angular velocity is constant for each place on the Earth‘s surface 2. the atmosphere rotates with the Earth 3. there are no nearby objects, either stationary or moving at a rate different from that of the Earth Which of the above is/are the correct explanation(s)?

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Answer D (official UPSC key)We do not feel the Earth's rotation because angular velocity is constant, the atmosphere rotates with the Earth and there are no nearby objects moving at a different rate

What is a constellation?

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Answer B (official UPSC key)A constellation is a pattern of stars that need not be equidistant from the Earth

Which of the following is/are environmental effects of Rotation of the Earth? 1. Daily or diurnal rhythm in daylight and air temperature 2. Flow path of both air and water are turned consistently in a sideward direction 3. The movement of the tides Select the correct answer using the code given below :

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Answer C (official UPSC key)Rotation of the Earth causes the diurnal rhythm of daylight and temperature, deflection of air and water flows, and influences tides

‗Black hole‘ is a

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Answer C (official UPSC key)A black hole is a star that has collapsed into itself and has very large gravitational acceleration

Which of the following statements is/are correct? 1. The Earth is nearest to the sun at Perihelion, which generally occurs on January 3 2. The Earth is farthest away from the Sun at Perihelion, which generally occurs on July 4 3. The Earth is farthest away from the Sun at Aphelion, which generally occurs on July 4 4. The Earth is nearest to the Sun at Aphelion, which generally occurs on January 3 Select the correct answer using the code given below:

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Answer C (official UPSC key)The Earth is nearest to the Sun at perihelion (around January 3) and farthest at aphelion (around July 4)

Which one of the following statements is not correct?

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Answer D (official UPSC key)Syzygy (Sun, Earth and Moon in a straight line) is not restricted to perihelion; conjunction causes solar and opposition causes lunar eclipses

Consider the Following statements Statement I : Sideral day is shorter than Solar day. Statement II : The motion of the Earth in its orbit around the Sun is termed as revolution. Code :

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Answer B (official UPSC key)A sidereal day is shorter than a solar day, and the Earth's motion around the Sun is revolution (both true, II does not explain I)

Why does the Earth assume the shape of an oblate ellipsoid?

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Answer A (official UPSC key)The Earth's rotation makes it bulge at the equator and flatten at the poles (oblate ellipsoid)

Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of the universe? 1. Detection of microwaves in space 2. Observation of redshift phenomenon in space 3. Movement of asteroids in space 4. Occurrence of supernova explosions in space Select the correct answer using the codes given below:

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Answer A (official UPSC key)Detection of microwaves in space and the redshift phenomenon are evidence for the continued expansion of the universe

Consider the following statements Statement I : The Earth is shaped more like a tangerine. Statement II : The Earth spins faster at the Poles. Code :

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Answer C (official UPSC key)The Earth is shaped like a tangerine (oblate), but it does not spin faster at the Poles (I true, II false)

Which of the following statements relating to the planet Venus is/are correct ? 1. It is the nearest planet from the Sun. 2. It is only slightly smaller than the Earth. 3. It has no atmosphere. Select the correct answer using the code given below ;

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Answer C (official UPSC key)Venus is only slightly smaller than the Earth; it is the second planet from the Sun and has a dense atmosphere

What is the difference between asteroids and comets? 1. Asteroids are small rocky planetoids, while comets are formed of frozen gases held together by rocky and metallic material. 2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury. 3. Comets show a perceptible glowing tail, while asteroids do not. Which of the statements given above is/are correct?

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Answer B (official UPSC key)Asteroids are rocky bodies and comets are frozen gases with rock and metal; comets show a glowing tail and asteroids do not; comets are not found mostly between Venus and Mercury

Assertion (A): To orbit around the Sun the planet Mars takes lesser time than the time taken by the earth. Reason (R): The diameter of the planet Mars is less than that of earth.

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Answer D (official UPSC key)Mars is smaller than the Earth but takes longer than the Earth to orbit the Sun (A false, R true)

Consider the following statements: 1. The Axis of the earth's magnetic field is inclined at 23 and a half to the geographic axis of the earth. 2. The earth's magnetic pole in the Northern Hemisphere is located on a Peninsula in Northern Canada. 3. The earth's magnetic equator passes through Thumba in South India. Which of the statements given above is/are correct?

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Answer B (official UPSC key)The Earth's northern magnetic pole lies on a peninsula in northern Canada and the magnetic equator passes through Thumba; the magnetic axis is not inclined at 23 and a half degrees to the geographic axis

Assertion (A): Existence of human life on Venus is highly improbable. Reason (R): Venus has extremely high level of carbon dioxide in its atmosphere.

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Answer A (official UPSC key)Human life on Venus is highly improbable because of its extremely high level of carbon dioxide (A and R true, R explains A)

Assertion (A): The same face of the moon is always presented to the earth. Reason (R): The moon rotates about its own axis in 23 and half days which is about the same time that it takes to orbit the earth.

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Answer C (official UPSC key)The same face of the Moon always faces the Earth, but the Moon rotates in about 27 days, not 23 and a half days (A true, R false)

Consider the following statements regarding asteroids: 1. Asteroids are rocky debris of varying size orbiting the sun 2. Most of the asteroids are small but some have diameter as large and 1000 km 3. The orbit of asteroids lies between the orbits of Jupiter and Saturn Of these statements:

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Answer C (official UPSC key)Asteroids are rocky debris of varying size orbiting the Sun, a few up to about 1000 km across; their orbits lie between Mars and Jupiter, not Jupiter and Saturn

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