Physics · Science General

Astronomy and Cosmology

4,450 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 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.

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

After a supernova explosion, the remains of the stellar core 

  1. will always be a neutron star.

  2. will be either a neutron star or a black hole.

  3. will always be a black hole.

  4. may be either a white dwarf, neutron star, or black hole
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Depending on the mass of the remaining core after a supernova, it will collapse into either a neutron star (if the mass is below the Tolman-Oppenheimer-Volkoff limit) or a black hole (if it exceeds that limit).

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

Analyzing the spectra of stars, the hottest stars are

  1. red

  2. orange

  3. bluish white

  4. there is no correlation between color and temperature
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The temperature of the stars are related to their colors by weins displacement law. Larger the temperature, smaller is their wavelength. Thus, of the colors given , red has maximum wavelength and hence smaller temperature, while bluish white has lesser wavelength and highest temperature. Thus, the star that emits bluish-white color has maximum temperature

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

White dwarfs

  1. are believed to be very small, perhaps about the size of the earth.

  2. contain atoms that have collapsed in the center, yet retain the standard distances between nuclei and electrons.

  3. are totally hypothetical stars, based on the best theories, but have never been observed directly.

  4. are found only on the far edge of the universe.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

White dwarf stars are characterized by a low luminosity, a mass on the order of that of the Sun, and a radius comparable to that of Earth.

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

What can we learn about a star from a life track on an H-R diagram?

  1. how long ago it was born

  2. when it will die

  3. where it is located

  4. what surface temperature and luminosity it will have at each stage of its life
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The HertzsprungRussell diagram, abbreviated HR diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures. More simply, it plots each star on a graph measuring the star's brightness against its temperature (color).

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

______________are the result of exploding stars that initially are more than about eight times the sun's mass.

  1. stars

  2. black hole

  3. supernova

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A supernova is the violent explosion of a massive star, typically one that is at least eight times the mass of the Sun, occurring at the end of its life cycle.

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

Which of the following is the stage where a massive star explodes and releases a lot of energy?

  1. Red supergiant

  2. Blackhole

  3. Main sequence

  4. Supernova
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Stars with very large masses can become black holes. A black hole releases a huge amount of gravitational energy, as material swirls toward its event horizon. This energy produces a jet of particles that streams over a distance of 300,000 light-years.

Multiple choice origin of universe universe and organic evolution biology

Total number of stars present in universe is :

  1. $10^{12} $
  2. $10^{16} $
  3. $10^{19} $
  4. $10^{22} $
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Scientific estimates of the number of stars in the observable universe are typically in the range of 10^22 to 10^24.

Multiple choice origin of universe universe and organic evolution biology

On an average a galaxy has stars :

  1. 1000 million

  2. 100,000 million

  3. 1,00,000 million

  4. 1000,000 million
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A typical galaxy like the Milky Way is estimated to contain roughly 100 billion stars, which is 100,000 million.