iGCSE Physics cosmology MC Questions (Edexcel)

Which of the following best describes the term Doppler effect?

• the bending of waves when they move from one medium to another

• the change in direction of waves in water

• the apparent change in wavelength which occurs when a source of waves is moving

• the rebounding of waves off a flat surface

The Doppler effect supports the theory for the Big Bang. Which statement correctly describes the Big Bang theory?

• The Universe is getting smaller because of an explosion

• The Universe is stationary but will come to an end because of a huge explosion.

• The Universe is expanding because of an explosion at the beginning of time.

• The Universe has lots of little explosions to create one big explosion.

If light from a star is shifted towards the blue end of the visible spectrum what does this say about how the star is moving?

• The star is stationary.

• The star is moving away from the Earth.

• The star is not moving.

• The star is moving towards the Earth.

Looking at the diagram below. What can be said about the galaxies in relation to the Earth?

• They are moving towards the Earth.

• They are moving away from the Earth.

• They are stationary.

• They are moving in different directions.

Cosmic microwave background (CMB) radiation is said to provide evidence for the Big Bang. Which of the following correctly describes CMB?

• energy released at the time of the Big Bang which is now in the microwave region of the electromagnetic spectrum

• microwaves emitted by the Universe

• light emitted by stars in the microwave spectrum

• light emitted from galaxies in the microwave spectrum

Light emitted from the Sun is 535 nm. A distant galaxy emits the same light but experiences the Doppler effect. This light is seen as 590 nm. What is the speed at which the galaxy is moving (speed of light is 3 × 10⁸ m/s)?

• 3.3 × 10⁸ m/s

• 2.9 × 10⁷ m/s

• 3.1 × 10⁷ m/s

• 2.0 × 10⁸ m/s

Light from a distant galaxy is shifted to 450 nm. The same light emitted from the Sun is approximately 600 nm. What is the speed of this galaxy in relation to the Earth (speed of light is 3 × 10⁸ m/s)?

• 7.5 × 10⁷ m/s

• 12 × 10⁸ m/s

• 3 × 10⁸ m/s

• 0.25 × 10⁷ m/s

Which of the galaxies is moving fastest?

• nearby

• furthest galaxy

• distant galaxy

• They are all moving at the same speed