This General Science quiz on Space Science: Stars, Galaxies and Satellites puts 10 multiple-choice questions to you, the verified MCQs published with GK24's note on the topic, 3 of them asked in real previous-year papers. Every question carries a full explanation of why the correct option is right and why the other options are wrong, so you learn the fact behind the answer rather than the letter. Attempt it right after reading the note, keep to the timer, and use the explanations at the end to mark what needs another look. Sit it again before the exam as a quick revision of the topic.
10 questions with answers and explanations
The source of the Sun's energy is
In the core of the Sun, at a temperature of about fifteen million kelvin, four hydrogen nuclei combine through the proton-proton chain to form one helium nucleus.
Read the full explanation →What is the reason behind the twinkling of stars?
A star is so far away that it is a point source of light.
Read the full explanation →Once a satellite has been launched into orbit, the only force governing its motion is the force of ______.
A satellite is given the required height and speed by its launch vehicle, and after that no engine is needed: the gravitational pull of the earth alone acts on it and provides the centripetal force that keeps it in a curved path, so the satellite keeps falling towards the earth…
Read the full explanation →A light year is a unit of
A light year is the distance travelled by light in vacuum in one year, which is about 9.46 times ten to the power twelve kilometres, or roughly nine and a half trillion kilometres.
Read the full explanation →Which is the nearest star to the earth after the Sun?
Being a red dwarf it cannot be seen with the naked eye, although it is the closest star to us after the Sun.
Read the full explanation →A geostationary satellite completes one revolution around the earth in
A geostationary satellite is placed in a circular orbit about 35,786 kilometres above the equator, where its period of revolution equals the period of rotation of the earth about its axis, and it moves from west to east like the earth, so it appears to stay over the same point…
Read the full explanation →Which is the brightest star in the night sky as seen from the earth?
It appears brightest because it is both luminous and close, about 8.6 light years away, and it is in fact a binary system with a white dwarf companion.
Read the full explanation →The solar system is a part of which galaxy?
It is a spiral galaxy of a few hundred billion stars, and the solar system lies in one of its spiral arms, far from the centre, which is why we see the galaxy edge on as a milky band across the night sky.
Read the full explanation →Which was the first Indian satellite, launched in 1975?
India's first satellite was named after the ancient astronomer and mathematician Aryabhata, was built by the Indian Space Research Organisation and was launched in April 1975 from the Soviet Union, since India had no launch vehicle of its own at the time; it carried experiments in X-ray astronomy and solar…
Read the full explanation →The Chandrasekhar limit is the maximum mass of which stellar remnant?
Subrahmanyan Chandrasekhar showed that a white dwarf, which is supported against gravity by the pressure of degenerate electrons, cannot have a mass greater than about 1.4 times the mass of the Sun; beyond that limit the star collapses further, and the work brought him the Nobel Prize in Physics in…
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