Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Cosmology
37 practice questions
Topics covered
Practice questions
11–18 of 18 · Easy
Question 11
2 marks · Easy
Answer and see the solution →Explain how the cosmic microwave background (CMB) radiation supports the Big Bang theory. Give two points in your answer.
Question 12
1 mark · Easy
Answer and check →Which observation about distant galaxies provides evidence that the universe is expanding?
- A.Their light is red-shifted.
- B.Their light is blue-shifted.
- C.Their light is unchanged.
- D.They emit only microwaves.
Question 13
1 mark · Easy
Answer and see the solution →A scientist observes that the absorption lines in the spectrum of a distant galaxy have moved towards longer wavelengths than those from our Sun. State the name of this effect.
Question 14
3 marks · Easy
Answer and see the solution →The universe is thought to have begun with a huge explosion called the Big Bang.
(a)[1 mark]State one observation from distant galaxies that supports the idea that the universe is expanding.
(b)[2 marks]Describe what the cosmic microwave background (CMB) radiation is.
Question 15
3 marks · Easy
Answer and see the solution →Light from a distant galaxy has a wavelength of 660 nm. The same spectral line measured from our Sun is 600 nm. Calculate the speed at which the galaxy is moving relative to Earth. (Speed of light = m/s)
Question 16
4 marks · Easy
Answer and see the solution →A student is looking at the light spectra from two galaxies, Galaxy A and Galaxy B, using a spectrometer. She notices that the absorption lines for Galaxy B are further towards the red end of the spectrum than those in Galaxy A.
(a)[2 marks]What is the name for the shift of absorption lines towards the red end of the spectrum, and what does it indicate about a galaxy’s motion relative to us?
(b)[2 marks]If Galaxy B’s absorption lines have shifted more than Galaxy A’s, what can you deduce about the relative speeds and distances of the two galaxies from us?
Question 17
4 marks · Easy
Answer and see the solution →Scientists use both red-shift and the cosmic microwave background (CMB) radiation to support their model of the universe.
(a)[2 marks]State what is meant by cosmic microwave background (CMB) radiation.
(b)[2 marks]Explain how observations of both red-shift and the CMB together provide evidence for the Big Bang.
Question 18
4 marks · Easy
Answer and see the solution →Light from the Sun has a wavelength of 500 nm. Light observed from a distant galaxy shows the same absorption line at a wavelength of 560 nm.
(a)[1 mark]Calculate the change in wavelength for the absorption line.
(b)[3 marks]The speed of light is m/s. Using the Doppler effect equation , calculate the speed at which the galaxy is moving away from Earth. Give your answer in km/s.