An analytical study of cosmology and theories surrounding the origin of the universe. This section tests key concepts such as the Big Bang Theory, Steady State Theory, cosmic expansion, dark matter, and the life cycle of stars.
Correct Answer:
(B) Origin of the Universe
The ''Big Bang Theory'' is related to the origin of the Universe, Milky Way and Solar System. This theory was propounded by George Lemaitre (1894-1966). Later in 1967, Robert Wagner explained this theory. According to this theory, the whole universe was concentrated in a hot and dense point some 13.7 or 13.8 billion years ago. Due to high concentration, there was a sudden explosion which was termed as Big-Bang.
Ques: 2
Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).
Assertion (A) : A black hole is an astronomical entity that cannot be seen by telescope.
Reason (R) : The gravitational fi eld 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) and (R) are true, and (R) is the correct explanation of
(A).
Correct Answer:
(A) and (R) are true, but (R) is not the correct explanation of
Ques: 3
The 'Black Hole' was first made known by
Correct Answer:
(C) S. Chandrashekhar
Subhramanyam Chandrashekhar was a great scientist and Nobel Prize winner who gave details on black hole theory. He is known for Chandrasekar limit which showed that there is a maximum mass which is supported against gravity by pressure made up of electrons and atomic nuclei (The value of this limit is about 1.44 times of solar Mass) which was derived by Chandrasekar in 1930. He was awarded Noble Prize jointly with W.A. Fowler in Physics in 1983.
Ques: 4
The terms 'Event Horizon', 'Singularity', 'String Theory' and 'Standard Model' are sometimes seen in the news in the context of
Correct Answer:
(A) Observation and understanding of the Universe
Event Horizon - It is a boundary which defines the area surrounding black hole in space. Beyond this boundary events cannot affect an outside observer.
Singularity - It is a place in the space-time where the gravitational area of the celestial bodies becomes infinite.
String Theory - String theory states that all matter in the universe is composed of tiny one-dimensional strings, not point particles.
Standard model - The standard model of particle physics is the theory describing three of the four known fundamental forces (the electromagnetic, weak and strong) in the universe as well as classifying all known elementary particles.
Ques: 5
A 'Supernova' is –
Correct Answer:
(D)
A dying star
A supernova is a large explosion that takes place at the end of a star's life cycle. A supernova happens where there is a change in the core or centre of a star. A change can occur in two different ways, with both resulting in a supernova. The first type of supernova happens in binary star systems wherein two stars orbit the same point. The second type of supernova occurs at the end of the single star's lifetime.
Ques: 6
How many constellations are in our space?
Correct Answer:
(B) 88
According to the International Astronomical Union, there are 88 constellations in the sky. Most of these imaginary patterns can be seen from the southern hemisphere. It will take a full year to get a glimpse of all the constellations.
Ques: 7
Which one of the following is NOT an Astronomical object?
Correct Answer:
(B) Brittle star
Brittle star is not an astronomical object. Brittle stars are echinoderms in the class ophiuroidea closely related to starfish. These are aquatic creatures and crawl on the sea surface, while Pulsar is celestial body emitting very regular pulses of radio waves. Quasar is an astronomical object of very high luminosity found in the centres of some galaxies at a distance of billions of light-years. A black hole is also a cosmic body of extremely intense gravity from which nothing (even light) can escape and formed by the death of a massive star. Thus, option (b) is the correct answer.