Cosmology (Edexcel GCSE Physics)

Exam Questions

2 hours11 questions
1a
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1 mark

The Big Bang theory is a theory about the origin of the Universe.

Evidence for the Big Bang theory is provided by red-shift and CMB radiation.

State what the abbreviation CMB is short for.

1b
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3 marks

Which of the following statements about the Big Bang theory are correct?  

Tick (✓) three boxes.

   

The Universe began 14 million years ago begin mathsize 36px style square end style
There was a giant explosion known as the Big Bang size 36px square
The Universe expanded from a single point size 36px square
It heated as it expanded to form the Universe today size 36px square
Each point in the Universe expands away from the others size 36px square
So, the further away galaxies are the slower they are moving size 36px square
 
1c
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5 marks

The table below shows statements of evidence for the theory.

Place a tick () in each row to indicate whether the statement is evidence from galactic redshift or CMB radiation.

Statement Evidence from Galactic Redshift Evidence from CMB Radiation
Astronomers discovered radiation in the microwave region of the electromagnetic spectrum coming from all directions    
Radiation is in the microwave region because the radiation initially from the big bang has redshifted as the Universe has expanded    
Observations of light spectrums from supernovae indicate that distant galaxies are receding    
Galaxies that are further away are moving faster, as their distance is proportional to their speed    
Light spectrums from distant galaxies show that light is redshifted which is evidence of the universe expanding    

1d
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2 marks

The Steady State theory is also a theory about the origin of the Universe.

State one similarity and one difference between the Big Bang theory with the Steady State theory. 

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2a
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1 mark

An astronomer observes light from a distant galaxy.

As the galaxy moves away from us, the spectrum of the light is 

square   A   blue-shifted

square   B   green-shifted

square   C   red-shifted

square   D   violet-shifted

    2b1 mark

    Light from a distant galaxy appears to have been redshifted.

    Which of the following rows correctly describes the change in the frequency and wavelength of the light when it is observed on Earth?



      frequency wavelength
    square  A decreases decreases
    square  B increases decreases
    square  C decreases increases
    square  D increases increases

      2c4 marks

      The diagram shows two people observing the same light source, which is in motion. The light is moving to the right.

      8-3-1c-e-redshift-labelling-light-bulb-sq-igcse

      Label the diagram with words or phrases from the list below.

        

      higher frequency lower frequency phase difference wavelength
      relative motion redshift blueshift star

        

      2d
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      1 mark

      The Big Bang theory is one theory for the origin of the Universe.

      The Big Bang theory suggests:

      • the Universe had a beginning
      • the Universe is still expanding

      Galactic redshift provides evidence that the universe is still expanding.

      Which of the following provides evidence that the Universe had a beginning?

      square   A   the discovery of other galaxies

      square   B   the discovery of moons around other planets

      square   C   the discovery of planets orbiting distant stars

      square   D   the discovery of cosmic microwave background radiation

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        3a
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        2 marks

        State the meaning of the term redshift.

        3b
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        1 mark

        Light from distant galaxies appears red-shifted to observers on Earth.

        Which of the following ideas does this provide evidence for?

         

        1. The Big Bang Theory

        2. The Universe is expanding

        3. Distant galaxies are moving both towards us and away from us

         

        square   A   1 only

        square   B   1 and 2

        square   C   2 only

        square   D   1, 2 and 3

          3c4 marks

          This passage is about redshift.

          Complete the following sentences by filling in the correct words in the gaps. Use words or phrases from the box below.

            

          stretch out slower expanding moving towards
          moving away faster blue red

            

           

          The phenomenon of redshift led to the discovery that almost all the galaxies in the Universe are ........................ from Earth.

           
          This led to the idea that the Universe must be ........................ 

           
          Light waves detected on Earth appear to ........................ as they travel through space, shifting them towards the ........................ end of the spectrum.

           
          The more shifted the light from a galaxy is, the ........................ the galaxy is ........................ from Earth.

          3d
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          6 marks

          The following passage is about the beginning of the Universe.

          Complete the sentences. 

          Choose answers from the box. 

          Each answer can be used once, more than once or not at all.

            

          faster slower hot cold
          heat up cool down expand shrink
          explosion Steady State Big Bang Big Crunch

            

           

          Around 14 billion years ago, the Universe was extremely ............... and dense initially.

          Then there was a giant ..............., which is known as the ...............................

          This caused the Universe to ............... from a single point to form the Universe today.

          Over time, each point moves away from the others which causes the Universe to ...............

          This is seen as galaxies move away from each other, and the further away they are the ............... they move.

          As a result of the initial ..............., the Universe continues to ................

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          1a1 mark

          The Big Bang theory is one theory for the origin of the Universe.

          The Big Bang theory suggests:

          • the Universe had a beginning
          • the Universe is still expanding

          Which of these provides evidence that the Universe had a beginning?

            A the discovery of other galaxies
            B the discovery of the moons of Jupiter
            C the discovery of planets orbiting distant stars
            D the discovery of cosmic microwave background (CMB) radiation
          1b2 marks

          Evidence that the Universe is still expanding comes from observations of light from distant galaxies.

          Describe how light from distant galaxies shows that the Universe is still expanding.

          1c2 marks

          The Steady State theory is also a theory about the origin of the Universe.

          Give one similarity and one difference when comparing the Big Bang theory with the Steady State theory.


          similarity.................................................................................

          difference...............................................................................

          1d6 marks

          Observations of the expanding Universe have shown that the further away a galaxy is from the Earth, the faster the galaxy is moving away from the Earth.

          Figure 4 shows how the velocity of galaxies is related to their distance from the Earth.

          fig-4-paper1h-oct2021-edexcel-gcse-physics

          Figure 4


          Mpc is a unit of distance used for large distances in space.

          i)
          Use Figure 4 to estimate the velocity of a galaxy that is 15 Mpc away from the Earth.

          [1]
          velocity = ............................. km/s
          ii)
          Calculate the gradient of the line shown in Figure 4.

          State the unit.

          [3]

          gradient = ........................... unit ..........................

          iii)
          The gradient of the line in Figure 4 can be used to estimate the age of the Universe.

          Explain why the gradient of the line in Figure 4 can only provide an estimate of the age of the Universe.

          [2]

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          2a1 mark

          Which row of the table is correct for both force and velocity?


                force velocity
            A scalar scalar
            B scalar vector
            C vector scalar
            D vector vector
          2b2 marks
          Figure 6 shows a satellite orbiting the Earth.

          fig-6-ipho-1h-june18-qp-edexcel-gcse-physics

          Figure 6

          i)
          State the name of the force that keeps the satellite in orbit around the Earth.

          [1]

          ii)
          Draw an arrow on Figure 6 to show the direction of the force acting on the satellite, that keeps the satellite in orbit around the Earth.

          Label this arrow ‘F’.

          [1]

          2c8 marks

          Satellites are used to gather data about the origin of the Universe.

          The Big Bang theory is a theory about the origin of the Universe.

          Evidence for the Big Bang theory is provided by red-shift and CMB radiation.

          i)
          Describe what is meant by red-shift.

          [2]

          ii)
          Explain how red-shift provides evidence for the Big Bang theory.

          [2]

          iii)
          The Cosmic Background Explorer (COBE) satellite observed CMB radiation from 1989 to 1993.
          State what the ‘M’ in CMB radiation stands for.

          [1]

          iv)
          State what is meant by ‘cosmic background radiation’.

          [1]

          v)
          Explain how the presence of CMB radiation provides evidence for the Big Bang theory.

          [2]

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          3a3 marks

          Explain the term galactic redshift.

          3b2 marks

          Explain why galactic redshift provides evidence to support the Big Bang theory.

          3c4 marks

          Describe and explain what can be deduced from the cosmic microwave background radiation (CMBR).

          3d4 marks

          Telescopes can be located on Earth or in space.

           
          (i)
          State two advantages of locating a telescope in space.
          [2]
          (ii)
          State two disadvantages of locating a telescope in space.
          [2]

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          4a3 marks

          The Big Bang theory attempts to explain the origins of the Universe.

          Describe the main ideas of the Big Bang theory.

          4b4 marks

          Explain the two pieces of evidence which support the Big Bang Theory of the origin of the Universe.

          4c3 marks

          State and explain the type of electromagnetic radiation the CMBR will change into over the next few billion years.

          4d2 marks

          Explain why our understanding of the beginning of the Universe is just a theory.

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          5a3 marks

          Define the Doppler effect.

          5b2 marks

          State the two properties of a wave which are observed to have changed due to the Doppler effect.

          5c3 marks

          An object is moving away from a stationary observer whilst emitting a steady sound wave.

           
           
          (i)
          State the property of the sound wave which increases.
          [1]
          (ii)
          State the property of the sound wave which decreases.
          [1]
          (iii)
          State the property of the sound wave which remains constant.
          [1]
          5d7 marks

          The following passage is about the Doppler effect.

           

          Complete the following sentences by circling the correct words:

           

          When a source starts to move away from / towards the observer, the wavelength of the wave broadens.

           

          For sound waves, sound, therefore, appears at a higher / lower frequency to the observer.

           

          For light waves, the light shifts towards the blue / red end of the electromagnetic spectrum due to its lower / higher frequency.

           

          When a source starts to move away from / towards the observer, the wavelength of the wave shortens.

           

          For sound waves, sound therefore appears at a higher / lower frequency to the observer.

           

          For light waves, the light shifts towards the blue / red end of the electromagnetic spectrum due to its lower / higher frequency.

           

          This is because blue / red light has a longer wavelength than blue / red light.

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          1a5 marks

          Stars may originate as a nebula.

          i)
          Describe the process that then occurs to produce the conditions necessary for nuclear fusion in a new star.

          [3]

          ii)
          The energy, E, released in nuclear fusion is equivalent to loss in mass, m, according to the equation.

          E = mc2

          where c is the velocity of light.

          c = 3.00×108 m/s

          In 1 second, the energy radiated by the Sun is 3.86 × 1026 J.

          Calculate the loss in mass of the Sun in 1 second.

          [2]

          loss in mass = .............................................................. kg

          1b6 marks

          The Big Bang theory gives an explanation for the origin of the Universe.

          Explain how evidence supports the ideas that

          • the Universe is expanding
          • the Universe began at a single point.
          1c2 marks

          A star has evolved to become a neutron star.

          The mass, M, of the neutron star, of radius R, is given by

          straight M equals fraction numerator 4 cross times pi cross times straight D cross times straight R cubed over denominator 3 end fraction        where D is a constant

          M = 4×1030 kg

          D = 6×1017 kg/m3

          Use the equation to calculate the value for R.


          R = .............................................................. m

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          2a
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          3 marks

          The Big Bang theory suggests that the universe is approximately 14 billion years old.

          Describe the evolution of the universe from the Big Bang until the present day. 

          2b
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          4 marks

          State the main principles of the steady state theory and explain why it is no longer used as the model representing the history of the universe.

          2c
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          2 marks

          Describe the observations of distant galaxies compared to closer galaxies and discuss what this tells us about the universe.

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          3a
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          3 marks

          Figure 1 below shows the spectrum of light received on the Earth from the Sun and from a star in a distant galaxy.

          redshifted-spectrum

          Figure 1

          The spectrum contains some characteristic dark lines, which occur at very specific wavelengths in the laboratory.

          Explain how the shift in the position of the dark lines provides evidence to support the Big Bang theory.

          3b
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          2 marks

          The data in Figure 1, along with data from other galaxies, can be used to plot a graph showing how the shift in position changes with the distance of each galaxy from the Earth, as shown in Figure 2.

          8-2-h-5b-hubble-graph-with-redshift-aqa-gcse-physics-sq

          A new galaxy is discovered with a red-shift of 0.02.

          Using the graph in Figure 2, estimate the distance to this new galaxy.

          Show clearly how you obtained your answer.

          3c
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          1 mark

          State an assumption you made in obtaining the answer to part (b).

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