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

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.

Multiple choice physics life cycle of stars movement of the earth properties of stars types of galaxies

Mass (in kg) of the massive object at the centre of the milky way galaxy is of the order.

  1. $10 ^ { 32 }$
  2. $10 ^ { 37 }$
  3. $10 ^ { 43 }$
  4. $10 ^ { 29 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The supermassive black hole at the center of the Milky Way, Sagittarius A*, has a mass estimated to be approximately 4 million solar masses. One solar mass is about 2 x 10^30 kg, so 4 x 10^6 * 2 x 10^30 = 8 x 10^36 kg, which is of the order 10^37.

Multiple choice physics life cycle of stars movement of the earth properties of stars types of galaxies

A galaxy that is moving toward the Earth will show:

  1. a red shift in the spectrum

  2. an increase in light years

  3. a decrease in brightness

  4. a blue shift in the spectrum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As galaxy move towards the earth the wavelength decreases and the frequency increase and colour changes to blue and also known as blue shift while opposite is known as red shift.

Multiple choice physics life cycle of stars movement of the earth properties of stars types of galaxies

The red shift in the spectral lines of light reaching us from other galaxies implies that these galaxies:

  1. are moving closer to one another

  2. are moving farther apart from one another

  3. consist predominantly of red giant stars

  4. are in rapid rotation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The red shift occurs due to increase due to increase in wavelength that would be due to the increasing distance between two galaxies, Red shift indicate that galaxy are mainly farther apart from one another