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

When looking at Main Sequence stars we can say that...

  1. the brighter, the cooler

  2. the brighter, the hotter

  3. the hotter, the dimmer

  4. The redder, the hotter
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For main sequence stars, there is a direct correlation between temperature and luminosity. Hotter stars appear brighter and bluer, while cooler stars appear dimmer and redder.

Multiple choice

What is a difference between planets and stars?

  1. they are the same

  2. planets twinkle

  3. stars twinkle

  4. stars make more money
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Stars twinkle because their light is distorted by the Earth's atmosphere, whereas planets appear as steady points of light because they are much closer to Earth.

Multiple choice evs sun and planets moon the moon's path in the sky the moon

The large grouping of stars, dust and gas held together by gravity are called:

  1. Galaxies

  2. Nebulae

  3. Pulse

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

Galaxies are large grouping of stars, dust and gas held together by gravity.
Nebulae : cosmic element of gas
Pulse: The rapidly pulse
Comets: Left ones from formation of planetary system

Multiple choice physics gravitation elementary ideas of astronomy shadow formation and optical medium light and shadow

Following factors may be responsible for the colour of a star.
I. The size of the star
II. The distance of the star from the earth
III. The surface temperature of the star
Which combination is correct?

  1. III only

  2. II only

  3. I and II only

  4. I, II and III
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factor responsible for colour of the star is surface temperature of the star it does not depend upon size of the star and distance of star from the earth.

Multiple choice

How many galaxies is the known universe made of?

  1. 5

  2. 5 billion

  3. 5 million

  4. 50 billion
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Current estimates from deep-field observations, such as those from the Hubble Space Telescope, suggest that the observable universe contains at least 50 billion to 2 trillion galaxies.

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

What do astronomers mean when they say that we are all "star stuff"? 

  1. that life would be impossible without energy from the Sun

  2. that life would be possible without energy from the Sun

  3. that the carbon, oxygen, and many elements essential to life were created by nucleosynthesis in stellar cores

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

The phrase star stuff refers to the fact that the heavy elements (like carbon, oxygen, and iron) that make up our bodies and the Earth were synthesized through nuclear fusion in the cores of stars and later dispersed into space.

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

The brightness of a star which can be seen from earth is called

  1. absolute magnitude

  2. apparent magnitude

  3. light year

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

Apparent magnitude measures the brightness of a star as observed from Earth. Absolute magnitude measures intrinsic luminosity at a standard distance, while light year is a unit of distance.

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

What is the first stage of a stars life.

  1. Nebula collapsing under itself

  2. Supernova of old star

  3. Planets collapsing

  4. Fusion of atoms
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A star is a luminous globe of gas producing its own heat and light by nuclear reactions (nuclear fusion). They are born from the nebula and consist mostly of hydrogen and helium gas. Surface temperatures range from 2000 C to above 30,000 C, and the corresponding colors from red to blue-white. 

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

What happens during the Main Sequence phase of a star?

  1. Hydrogen atoms are fused into helium atoms

  2. The star explodes and releases energy

  3. Helium atoms are fused into heavy elements

  4. The star is born out of dust and gas
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Main sequence stars fuse hydrogen atoms to form helium atoms in their cores. About 90 percent of the stars in the universe, including the sun, are main sequence stars. 

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

A main sequence star is 

  1. A star that shines steadily due to nuclear fusion

  2. Several stars close together

  3. A star with planets orbiting it

  4. A Nebula that skips a protostar and is instantly turns into a star.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Main sequence stars are in the longest stage of their life cycle, where they fuse hydrogen into helium in their cores. This process releases the energy that makes them shine steadily.