Physics · Science General

Astronomy and Cosmology

4,498 Questions

This topic provides questions on astronomy, cosmology, and the physical universe. It covers subjects like the Hubble sequence, constellations, dark matter, and stellar evolution. These questions help build a strong foundation for general science exam sections.

Galaxies and clustersConstellations and starsStellar evolutionSpace observatories

Astronomy and Cosmology Questions

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

What is happening inside a star while it expands into a subgiant?

  1. It is fusing hydrogen into helium in the core.

  2. It is fusing hydrogen into helium in a shell outside the core.

  3. It is fusing helium into carbon in the core.

  4. It is fusing helium into carbon in a shell outside the core.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fusion reactions take place and all hydrogen gets fuses to helium, thereby depleting hydrogen completely

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

Which two energy sources can help a star maintain its internal thermal pressure? 

  1. nuclear fusion and gravitational contraction

  2. nuclear fission and gravitational contraction

  3. chemical reactions and gravitational contraction

  4. nuclear fusion and chemical reactions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fusion reaction happen on star   such as sun where hydrogen combine to form $He$ a fusion reaction releasing energy and gravitational contraction occur due to very high gravitational pull.

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

What happens when a star exhausts its core hydrogen supply?

  1. Its core contracts, but its outer layers expand and the star becomes bigger and brighter.

  2. It contracts, becoming smaller and dimmer.

  3. It contracts, becoming hotter and brighter.

  4. It expands, becoming bigger but dimmer.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase.

When they reach this phase, hydrogen in them almost becomes depleted off and they become brighter and hotter and becomes low-mass white dwarfs

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

Which of the following properties make flare stars so active?

  1. fast rotation rates

  2. deep convection zones

  3. convecting cores

  4. both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Flare stars have deep convection zone which help in rapid transition of energy produced in the star and also has convecting cores thus both deep convection zone and convecting cores make flare stars so active.

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

Which of the following sequences correctly describes the stages of life for a low-mass star? 

  1. red giant, protostar, main-sequence, white dwarf

  2. protostar, main-sequence, red giant, white dwarf

  3. protostar, red giant, main-sequence, white dwarf

  4. protostar, main-sequence, white dwarf, red giant
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Low-mass stars begin as collapsing clouds of gas forming a protostar, ignite hydrogen fusion in their core during the main-sequence phase, expand into red giants when core hydrogen is depleted, and finally shed their outer layers to leave behind a white dwarf.

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

Which of the following stars will certainly end its life in a supernova? 

  1. the Sun

  2. a red giant star

  3. a 10-solar-mass star

  4. a neutron star
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Supernova being the last stages of a star, will happen only if the mass of the star exceeds the solar mass and hence a 10 solar mass star will have a high probability of becoming a supernova

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

What is a carbon star? 

  1. a red giant star whose atmosphere becomes carbon-rich through convection from the core

  2. a star that fuses carbon in its core

  3. another name for a white dwarf, a remnant of a star made mainly of carbon

  4. a star that is made at least 50 percent of carbon
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Due to triple helium process, helium fusion takes place and carbon is formed due to convection from the core

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

What is a planetary nebula

  1. a disk of gas surrounding a protostar that may form into planets

  2. what is left of the planets around a star after a low-mass star has ended its life

  3. the expanding shell of gas that is no longer gravitationally held to the remnant of a low-mass star

  4. the molecular cloud from which protostars form
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A ring-shaped gaseous structure formed by an expanding shell of gas round an ageing star is known as nebula

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

Compared to the star it evolved from, a white dwarf is 

  1. hotter and brighter.

  2. hotter and dimmer.

  3. cooler and brighter.

  4. cooler and dimmer.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A star's temperature is only 5,800 K, while a white dwarf has a temperature of 100,000 K. A white dwarf's faint luminosity comes from the emission of stored thermal energy; no fusion takes place in a white dwarf wherein mass is converted to energy. Hence it is dimmer than star

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

What happens to the core of a star after a planetary nebula occurs? 

  1. It contracts from a protostar to a main-sequence star.

  2. It breaks apart in a violent explosion.

  3. It becomes a white dwarf.

  4. It becomes a neutron star.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

After a low-to-medium mass star sheds its outer layers as a planetary nebula, the remaining core, which is no longer undergoing fusion, becomes a dense, hot object known as a white dwarf.

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

During which of the following phases does the core of a massive star have so much gravity that even light can't escape?

  1. Neutron Star

  2. Supernova

  3. White Dwarf

  4. Black Hole
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Once a black hole has formed, it can continue to grow by absorbing mass from its surroundings. The gravitational force becomes so intense that even light cannot escape from it

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

Why do massive stars have shorter lifespans than average stars?

  1. They are excited to get through their lifecycles faster

  2. They have less steps in their lifecycles

  3. They burn their fuel faster

  4. They have less fuel to burn
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Massive stars live shorter lives than the common small stars because even though they have a larger amount of hydrogen for nuclear reactions, their rate of consuming their fuel is very much greater.

Multiple choice physics life cycle of stars evolution and end stages of stars the stars stars

In which of the following stages will our Sun form heavy elements?

  1. Red giant

  2. Stellar Nebula

  3. Blackhole

  4. Main sequence
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 In approximately 5 billion years, the sun will begin the helium-burning process, turning into a red giant star. In a red giant, helium nuclei fuse to make carbon, followed by heavier elements such as nitrogen and oxygen.