1. The “Big Bang Theory” is related to –
(a) Continental Drifts
(b) Origin of the Universe
(c) Origin of the Himalayas
(d) Eruption of Volcanoes
[R.A.S./R.T.S.(Pre) 2007]
Ans. (b) Origin of the Universe
- The Big Bang Theory explains the beginning of the Universe, Milky Way and Solar System.
- It was put forward by George Lemaitre in 1894 and later elaborated on by Robert Wagner in 1967.
- This theory suggests that a long time ago, all of the universe was in a tiny, very hot and dense spot.
- This spot suddenly exploded, which is known as the Big Bang.
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2. The Milky Way is classified as –
(a) Spiral Galaxy
(b) Electrical Galaxy
(c) Irregular Galaxy
(d) Round Galaxy
[U.P.P.C.S. (Pre) 2001]
Ans. (a) Spiral Galaxy
- Georges Lemaitre proposed a theory that around 13.8 billion years ago, all of the cosmic matter was condensed into one dense mass.
- This mass spread apart to create many galaxies.
- We can see all of these galaxies together as the Universe.
- Each galaxy is estimated to contain around 100 billion stars.
- Our solar system is located in the Milky Way, which is a specific type of galaxy.
- Galaxies come in a variety of shapes, such as elliptical, spiral, and irregular.
- In 2005, the Spitzer Space Telescope provided evidence that the Milky Way is a barred spiral shape.
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3. Time taken by the Sun to revolve around the centre of our galaxy is –
(a) 2.5 crores years
(b) 10 crores years
(c) 25 crores years
(d) 50 crores years
[40th B.P.S.C. (Pre) 1995]
Ans. (c) 25 crores years
- The Sun is a star in our Milky Way galaxy.
- Every star in the galaxy orbits around the centre, and how long it takes depends on how far away the star is from the centre.
- The Sun is quite far away, so it takes a long time to go around – between 225 and 250 million years.
- This is called a Cosmic or Galactic Year.
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4. The colour of the star indicates its –
(a) Distance from Sun
(b) Lighting or glow
(c) Distance from earth
(d) Temperature
[I.A.S. (Pre) 1994]
Ans. (d) Temperature
- The color of a star tells us how hot it is. Stars of different colors are different temperatures.
(Colours) |
(Temperature range) |
Blue |
50,000-28,000 K |
Blue-white |
28,000-10,000 K |
White |
10,000-7500 K |
White Yellow |
7500-6000 K |
Yellow |
6000-4900 K |
Orange |
4900-3500 K |
Red |
3500-2000 K |
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5. The limit beyond which stars suffer internal collapse is called :
(a) Chandrasekhar limit
(b) Eddington limit
(c) Hoyle limit
(d) Fowler limit
[U.P.P.C.S. (Pre) 1997]
Ans. (a) Chandrasekhar limit
- Subrahmanyan Chandrasekhar was an Indian astrophysicist who discovered the “Chandrasekhar Limit”, which is the maximum mass that a white dwarf star can have before collapsing into a neutron star or a black hole.
- This mass was found to be about 1.44 times the mass of the sun.
- In 1983, Chandrasekhar was given the Nobel Prize in Physics for his research into the life cycles of stars.
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6. Assertion (A): A black hole is an astronomical entity that cannot be seen by telescope.
Reason (R): The gravitational field on a black hole is so strong that it does not allow even light to escape.
In the context of the above statements, which one of the following is correct :
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(c) (A) is true, but R is false.
(d) (A) is false, but R is true.
[U.P.P.C.S.(Pre) 2003, U.P.P.C.S.(Pre) 2001]
Ans. (a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
- We cannot see a black hole with a telescope because its strong gravitational field caused by its high density blocks all types of radiation, even light.
- However, we can tell that a black hole exists by looking at the stars, gases, and masses around it using a space telescope.
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7. A ‘black hole’ is a body in space which does not allow any type of radiation to come out. This property is due to its –
(a) Very small size
(b) Very large size
(c) High density
(c) Very low density
[I.A.S. (Pre) 2000]
Ans. (c) High density
- We cannot see a black hole with a telescope because its strong gravitational field caused by its high density blocks all types of radiation, even light.
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8. The ”Black Hole Theory” was propounded by :
(a) C.V. Raman
(b) H.J. Bhabha
(c) S.Chandrashekhar
(d) Hargovind Khurana
[U.P.P.C.S. (Pre) 1996]
Ans. (c) S.Chandrashekhar
- On January 11th, 1935, Dr. S. Chandrasekhar spoke at the Royal Astronomical Society of London and explained about Black Holes.
- He said that white dwarf stars become Black Holes when they reach a certain size.
- In 1983, he was awarded the Nobel Prize in Physics with W.A. Fowler.
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9. The terms ‘Event Horizon’, ‘Singularity’, ‘String Theory’ and ‘Standard Model’ are sometimes seen in the news in the context of –
(a) Observation and understanding of the Universe
(b) Study of the solar and lunar eclipses
(c) Placing satellites in the orbit of the Earth
(d) Origin and evolution of living organisms on the Earth
[I.A.S. (Pre) 2017]
Ans. (a) Observation and understanding of the Universe
- Event Horizon – is the edge of a black hole in space. Anything that happens beyond this edge can’t be seen from the outside.
- Singularity – It is a point in space and time where the gravitational force of celestial objects reaches an unlimited amount.
- String Theory – suggests that everything in the universe is made up of small, thin strings, rather than tiny dots.
- The standard model – of particle physics is a theory that explains the 3 main forces in the universe (electromagnetic, weak and strong) and identifies all the known tiny particles.
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10. A ‘Supernova’ is –
(a) An asteroid
(b) A black hole
(c) A comet
(d) A dying star
[U.P. Lower Sub. (Mains) 2015]
Ans. (d) A dying star
- A supernova is a huge explosion that happens when a star reaches the end of its life.
- This explosion can happen in one of two ways:
- Either two stars colliding in one system
- Or when a single star reaches the end of its lifetime.
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11. How many constellations are in our space?
(a) 87
(b) 88
(c) 89
(d) 90
[44th B.P.S.C. (Pre) 2000]
Ans. (b) 88
- The International Astronomical Union states that there are 88 constellations visible in the sky.
- Most of these patterns are only viewable from the southern hemisphere.
- It will take a full year to observe all of them.
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12. Which one of the following is not an Astronomical object?
(a) Pulsar
(b) Brittle star
(c) Black hole
(d) Quasar
[I.A.S. (Pre) 1993]
Ans. (b) Brittle Star
- Brittle stars are aquatic animals, related to starfish, while Pulsar and Quasar are very bright objects in the sky that are far away, and a Black Hole is a powerful force in space from which nothing can escape that is caused by a dying massive star.
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13. A group of stars arranged in a particular shape, is called–
(a) Milky Way
(b) Constellation
(b) Andromeda
(d) Solar system
[U.P.P.C.S. (Pre) 2013]
Ans. (b) Constellation
- A constellation is a pattern of stars that forms a shape.
- These shapes have been given names of figures from mythology.
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14. Hubble space telescope has captured, for the first time, detailed image of the surface of a distant star. Name of the star is –
(a) Virgo
(b) 70 Virgins
(c) Betelgeuse
(d) Big Dipper
[U.P.P.C.S. (Pre) 1995]
Ans. (c) Betelgeuse
- Betelgeuse is the second brightest star in the constellation of Orion.
- It is 650 light years away from Earth.
- It was first spotted by Sir John Herschel in 1836, but in 1995 the Hubble Space Telescope took pictures of it.
- It was the second star after the Sun to have its image taken.
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15. Consider the following Statements –
A person in a spacecraft situated at the mid of earth and Sun will see that –
1. The sky is black
2. Stars do not twinkle
3. The temperature outside the spacecraft is more than that of the earth surface.
Which of the following is true –
(a) Only 3
(b) 1 and 2
(c) 1 and 3
(d) 1, 2 and 3
[I.A.S. (Pre) 1996]
Ans. (b) 1 and 2
- When in space, the sky appears dark because there is no atmosphere.
- Stars don’t twinkle either because the atmosphere is needed for the light to pass through and make them sparkle.
- On Earth, the atmosphere causes the sky to appear blue and stars to twinkle.
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16. “Light Year” is the unit of –
(a) Time
(b) Distance
(c) Luminosity
(d) None of these
[M.P.P.C.S. (Pre) 1994]
Ans. (b) Distance
- Light year is the measurement of the distance light can cover in one year in a space with no air.
- It is 9.4 trillion km.
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17. Which one of the following is not a natural unit of time?
(a) Tropical year
(b) Lunar month
(c) Standard time
(d) Day
[Uttarakhand P.C.S. (Pre) 2016]
Ans. (c) Standard time
- The time set by the government of a particular area or country is known as standard time.
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18. The unit of measuring the distance between the stars is known as
(a) Stellar mile
(b) Cosmic km.
(c) Galactic unit
(d) Lightyear
[Uttarakhand P.C.S. (Pre) 2006]
Ans. (d) Lightyear
- A light year is a unit of measurement used to measure the distance between stars.
- It is the distance light travels in one year, which is 3 million kilometers per second.
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19. If the stars are seen to rise perpendicular to the horizon by an observer, he is located on the –
(a) Equator
(b) Tropic of Cancer
(c) South Pole
(d) North Pole
[I.A.S. (Pre) 2001]
Ans. (a) Equator
- The stars move in the same direction around the North and South poles in the sky.
- These poles are directly above the North and South poles on the Earth, and the Equator in the sky is almost directly above the Equator on the Earth.
- This causes the stars to be blocked from view in the East and West when they are near the horizon.
- The number of degrees at the celestial poles is the same as the latitude of the Equator on the horizon.
- If someone looks up and sees the stars directly above them, they are at the equator.
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20. A person stood alone in a desert on a dark night and wanted to reach his village which was situated 5 km East of the point where he was standing. He had no instrument to find the direction but he located the pole star. The most convenient way now to reach his village is to walk in the
(a) Direction facing the pole star
(b) Direction opposite to the pole star
(c) Direction keeping the pole star to his left
(d) Direction keeping the pole star to his right
[I.A.S. (Pre) 2012]
Ans. (c) Direction keeping the pole star to his left
- The North Star is in the northern sky.
- To go east, it should always be on the left.
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21. The group of stars that indicates the direction of the pole, is
(a) Saptarishi
(b) Mrig
(c) Scorpio
(d) Taurus
[41st B.P.S.C. (Pre) 1996]
Ans. (a) Saptarishi
- Saptarishi is a collection of stars that show us the way to the North Pole.
- Therefore, choice (a) is the correct answer.
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22. Which one of the following is not related to space terminology :
(a) Telemetering
(b) Weightlessness
(c) Cislunar
(d) Byte
[U.P.P.C.S. (Pre) 1997]
Ans. (d) Byte
- In computing, a byte is a collection of binary numbers (0s and 1s) that are treated as one unit.
- Other terms related to this are related to storage.
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