Doppler effect, Redshift and expansion of the Universe

What is the Doppler Effect?

• The change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source.

• The bending of light as it passes through different mediums.

• The splitting of light into its component colours.

• The absorption of light by a black hole.

Which of the following best describes redshift?

• The increase in frequency of light from a source moving towards the observer.

• The decrease in frequency of light from a source moving away from the observer.

• The change in direction of light as it passes through a prism.

• The absorption of light by interstellar dust.

What is the Cosmic Microwave Background (CMB)?

• The light emitted by stars in the Milky Way.

• The radiation left over from the Big Bang.

• The light from distant galaxies.

• The heat emitted by the Sun.

What does Hubble's Law state?

• The speed of light is constant in a vacuum.

• The universe is contracting at a constant rate.

• The recessional velocity of galaxies is proportional to their distance from us.

• The gravitational force between two objects is inversely proportional to the square of the distance between them.

Which of the following is an application of redshift?

• Measuring the temperature of stars.

• Determining the chemical composition of a star.

• Calculating the distance of galaxies from Earth.

• Measuring the mass of planets.

What is recessional velocity?

• The speed at which a galaxy is moving towards us.

• The speed at which a galaxy is moving away from us.

• The speed of rotation of a galaxy.

• The speed of light in a vacuum.

How does the Doppler Effect affect sound waves?

• It changes the amplitude of the sound.

• It changes the pitch of the sound.

• It changes the speed of the sound.

• It changes the direction of the sound.

What happens to light waves from a star moving away from Earth?

• They become blue-shifted.

• They become red-shifted.

• They remain unchanged.

• They become absorbed by the atmosphere.

What is the significance of the Cosmic Microwave Background?

• It provides evidence for the Big Bang theory.

• It shows the current temperature of the universe.

• It indicates the presence of dark matter.

• It proves the existence of black holes.

Which scientist is credited with discovering the expansion of the universe?

• Albert Einstein

• Isaac Newton

• Edwin Hubble

• Galileo Galilei