Stars Practice Questions
20 free Stars practice questions for the Static GK. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which process is the primary source of energy for stars like our Sun?
- A Nuclear Fusion
- B Nuclear Fission
- C Chemical Combustion
- D Heat Transfer
Correct answer: Nuclear Fusion
Nuclear fusion involves the merging of hydrogen nuclei to form helium under extreme temperature and pressure. This process releases a massive amount of energy in the form of light and heat.
What is the most abundant element found in a typical young star?
- A Helium
- B Carbon
- C Nitrogen
- D Hydrogen
Correct answer: Hydrogen
Hydrogen makes up approximately 75% of the elemental mass of the universe and is the primary fuel for stars. As a star ages, it converts this hydrogen into heavier elements like helium.
Which star is the closest to our Solar System, located about 4.24 light-years away?
- A Sirius
- B Alpha Centauri A
- C Betelgeuse
- D Proxima Centauri
Correct answer: Proxima Centauri
Proxima Centauri is a small, low-mass red dwarf star. It is part of the Alpha Centauri star system but is slightly closer to Earth than the other two stars in the trio.
The Hertzsprung-Russell (H-R) diagram plots stars based on which two primary characteristics?
- A Luminosity and Temperature
- B Mass and Rotational Velocity
- C Age and Distance
- D Composition and Rotation
Correct answer: Luminosity and Temperature
The H-R diagram is a fundamental tool in astronomy that shows the relationship between a star's absolute magnitude (brightness) and its spectral type (color/temperature). Most stars fall along a line called the Main Sequence.
What is the final evolutionary stage for a star with a mass similar to that of our Sun?
- A Black Hole
- B Neutron Star
- C Supernova
- D White Dwarf
Correct answer: White Dwarf
After exhausting its nuclear fuel, a Sun-like star sheds its outer layers to form a planetary nebula. The remaining hot, dense core is known as a white dwarf, which eventually cools over billions of years.
Which color indicates the hottest surface temperature for a star?
- A Red
- B Yellow
- C White
- D Blue
Correct answer: Blue
In astronomy, blue stars are the hottest, with surface temperatures exceeding 30,000 K. Red stars are relatively cool, with surface temperatures around 3,000 K.
A massive star that collapses and explodes at the end of its life cycle is known as a:
- A Protostar
- B Red Giant
- C Quasar
- D Supernova
Correct answer: Supernova
A supernova is one of the most energetic events in the universe, occurring when a massive star runs out of fuel and its core collapses. The resulting explosion can briefly outshine an entire galaxy.
What is the 'Chandrasekhar Limit', approximately 1.44 times the mass of the Sun?
- A The maximum mass of a white dwarf
- B The distance of the habitable zone
- C The speed of a pulsar's rotation
- D The age of the oldest known star
Correct answer: The maximum mass of a white dwarf
Named after Subrahmanyan Chandrasekhar, this limit defines the maximum mass a stable white dwarf star can have. If a star exceeds this mass, it will collapse further into a neutron star or black hole.
Which of these is the brightest star in the night sky as seen from Earth?
- A Polaris
- B Sirius
- C Vega
- D Rigel
Correct answer: Sirius
Sirius, also known as the Dog Star, has an apparent magnitude of -1.46. Its brightness is due to its intrinsic luminosity and its relative proximity to Earth (8.6 light-years).
What remains after a massive star's core collapses into an incredibly dense object composed entirely of subatomic particles?
- A Brown Dwarf
- B Neutron Star
- C Red Dwarf
- D Planetary Nebula
Correct answer: Neutron Star
Neutron stars are so dense that a single teaspoon of their material would weigh billions of tons. They are the remnants of stars that were much larger than the Sun but not large enough to become black holes.
What is a 'Light-year' a measure of?
- A Time
- B Intensity
- C Distance
- D Mass
Correct answer: Distance
A light-year is the distance light travels in a vacuum in one Julian year (approx. 9.46 trillion km). It is the standard unit for measuring the vast distances between stars.
The 'North Star', used for navigation in the Northern Hemisphere, is scientifically known as:
- A Antares
- B Polaris
- C Betelgeuse
- D Altair
Correct answer: Polaris
Polaris is located very close to the North Celestial Pole. Because of its position, it appears almost stationary in the sky while other stars appear to rotate around it.
Which type of star is the most common in the Milky Way galaxy?
- A Red Giant
- B Red Dwarf
- C Yellow Dwarf
- D Neutron Star
Correct answer: Red Dwarf
Red dwarfs are small, cool, and relatively faint stars. They burn their fuel very slowly, allowing them to live for trillions of years, far longer than any other type of star.
What is the term for a group of stars that form a recognizable pattern or shape in the sky?
- A Nebula
- B Galaxy
- C Constellation
- D Asteroid Belt
Correct answer: Constellation
Constellations are regions of the celestial sphere that contain a group of stars. There are 88 officially recognized constellations, many named after mythological figures or animals.
Which star is a well-known red supergiant located in the constellation Orion and is expected to go supernova in the future?
- A Rigel
- B Aldebaran
- C Betelgeuse
- D Eta Carinae
Correct answer: Betelgeuse
Betelgeuse marks the 'shoulder' of Orion. It is so large that if it replaced our Sun, its surface would extend past the orbit of Mars and possibly Jupiter.
What are 'Pulsars'?
- A Young protostars that are still forming in a nebula
- B Rotating neutron stars that emit beams of radiation
- C Planets that orbit around two stars simultaneously
- D Dormant black holes that have ceased active growth
Correct answer: Rotating neutron stars that emit beams of radiation
Pulsars emit beams of electromagnetic radiation from their magnetic poles. As they rotate, these beams sweep across Earth like a lighthouse beam, appearing as regular pulses.
The apparent shift in the position of a nearby star against a distant background, used to measure distance, is called:
- A Doppler Effect
- B Parallax
- C Redshift
- D Aberration
Correct answer: Parallax
Stellar parallax is measured by observing a star from two different points in Earth's orbit. The smaller the parallax angle, the farther away the star is from us.
Which of the following is often called a 'Failed Star' because it lacks enough mass to sustain nuclear fusion?
- A White Dwarf
- B Red Giant
- C Protostar
- D Brown Dwarf
Correct answer: Brown Dwarf
Brown dwarfs have masses between that of a large planet and a small star. They are not massive enough to trigger the fusion of ordinary hydrogen in their cores.
Which layer of a star is visible to us and is considered its 'surface'?
- A Core
- B Radiative Zone
- C Photosphere
- D Corona
Correct answer: Photosphere
The photosphere is the layer of a star from which light is emitted. In our Sun, it is about 500 km thick and has a temperature of approximately 5,500°C.
What is the 'Parsec' unit equivalent to in light-years?
- A 1.0 light-year
- B 9.46 light-years
- C 150 million light-years
- D 3.26 light-years
Correct answer: 3.26 light-years
A parsec (parallax second) is a unit of distance used in astronomy. It is the distance at which an object has a parallax of one arcsecond.