Galaxies and the Universe

Physics ⇒ Earth and Space Physics

Galaxies and the Universe starts at 9 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Galaxies and the Universe. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.

See sample questions for grade 11

A galaxy is observed to have a redshift corresponding to a velocity of 30,000 km/s. If Hubble's constant is 70 km/s/Mpc, calculate its approximate distance in megaparsecs (Mpc).

Calculate the distance in light-years to a galaxy if its light takes 2 million years to reach Earth.

Describe the role of gravity in the formation and evolution of galaxies.

Describe what is meant by a light-year.

Describe what is meant by the term 'cosmic microwave background radiation'.

Explain the difference between a galaxy cluster and a supercluster.

Explain the difference between a spiral galaxy and an elliptical galaxy.

Explain the significance of redshift in the study of galaxies.

Explain why astronomers use telescopes that detect different wavelengths (such as radio, infrared, and X-ray) to study galaxies.

What is a quasar?

What is the name of the theory that explains the origin of the universe?

A distant galaxy is observed to have a spectral line shifted from 500 nm (rest wavelength) to 600 nm. Calculate the galaxy's recessional velocity using the formula v = c × (Δλ/λ₀), where c = 3.0 × 10⁵ km/s.

A student claims that the expansion of the universe means that galaxies themselves are expanding. Is this statement true or false? Explain your answer.

Context: Astronomers observe two galaxies, A and B. Galaxy A is 100 million light-years away and appears twice as bright as Galaxy B, which is at an unknown distance. Assuming both galaxies have the same intrinsic luminosity, estimate the distance to Galaxy B.

Describe the process by which astronomers determine the mass of a galaxy using the orbital velocities of stars at different distances from the galactic center.

Explain how gravitational lensing provides evidence for the existence of dark matter in galaxy clusters.