DP Physics Questionbank

• Syllabus

Option D: Astrophysics

Sub sections and their related questions

Option D: Astrophysics (Core topics)

• 15M.3.HL.TZ1.4a: Identify whether star X is on the main sequence. Assume that n = 3.5 in the mass–luminosity...
• 15M.3.HL.TZ1.4b: (i) State the evolution of star X. (ii) Explain the eventual fate of star X.
• 15M.3.HL.TZ1.5a: The light from distant galaxies is red-shifted. Explain how this red-shift arises.
• 15M.3.HL.TZ1.5b: The graph shows the variation of recession speed with distance from Earth for some galactic...
• 15M.3.SL.TZ1.15a: (i) Show that the surface temperature of Barnard’s star is about 3000 K. (ii) Suggest why...
• 15M.3.SL.TZ1.15b: (i) Determine, in astronomical units (AU), the distance between Earth and Barnard’s star. (ii)...
• 15M.3.SL.TZ2.13a: State the star type for A, B and C.
• 15M.3.SL.TZ2.13c: The apparent brightness of C is 3.8 $\times$ 10–10 Wm–2. The luminosity of the Sun is 3.9...
• 15M.3.SL.TZ2.13d: The graph shows the variation with wavelength λ of the intensity I of the radiation emitted by...
• 15M.3.SL.TZ2.15a: State what is meant by the expansion of the universe.
• 15M.3.SL.TZ2.15b: Red-shift of light from distant galaxies provides evidence for an expanding universe. (i) State...
• 15M.3.HL.TZ2.4a: The mass of a main sequence star is two solar masses. Estimate, in terms of the solar luminosity,...
• 15M.3.HL.TZ2.4b: The star in (a) will eventually leave the main sequence. State (i) the condition that must be...
• 15M.3.HL.TZ2.4c: Explain why a white dwarf maintains a constant radius.
• 15M.3.HL.TZ2.5a: A galaxy a distance d away emits light of wavelength λ. Show that the shift in wavelength Δλ, as...
• 15M.3.HL.TZ2.5b: Light of wavelength 620 nm is emitted from a distant galaxy. The shift in wavelength measured on...
• 15N.3.HL.TZ0.1c: Discuss whether Hubble’s Law can be used to determine reliably the distance from Earth to this star.
• 15N.3.HL.TZ0.3b.i: calculate the distance of this galaxy from Earth.
• 15N.3.HL.TZ0.3b.ii: discuss why different measurements of the Hubble constant do not agree with each other.
• 14M.3.SL.TZ1.11: This question is about comets. Outline the nature of a comet.
• 14M.3.SL.TZ1.12: This question is about the life history of stars. Outline, with reference to pressure, how a...
• 14M.3.HL.TZ1.2a: Outline, with reference to pressure, how a star on the main sequence maintains its stability.
• 14M.3.HL.TZ1.2b: A star with a mass equal to that of the Sun moves off the main sequence. Outline the main...
• 14M.3.HL.TZ1.2c: Compare the fate of the star in (b) with that of a star of much greater mass.
• 14M.3.HL.TZ1.3c: The luminosity of the Sun is 3.8×1026 W. Determine the mass of Sirius A relative to the mass of...
• 14M.3.HL.TZ1.4a: (i) State, in terms of the arrangement of galaxies, the present large-scale distribution of mass...
• 14M.3.HL.TZ1.4b: State and explain the observational evidence for your answer to (a)(ii).
• 15N.3.SL.TZ0.14a: Outline why the star appears to have shifted from position A to position B.
• 15N.3.SL.TZ0.14b.i: Draw a diagram showing $d$, $D$ and $\theta$.
• 15N.3.SL.TZ0.14b.ii: Explain the relationship between $d$, $D$ and $\theta$.
• 15N.3.SL.TZ0.14b.iii: One consistent set of units for $D$ and $\theta$ are parsecs and arc-seconds. State one...
• 15N.3.SL.TZ0.14c: Suggest whether the distance from Earth to this star can be determined using spectroscopic parallax.
• 15N.3.SL.TZ0.15c: The following data are given for the Sun and a star Vega.      Luminosity of the Sun    ...
• 15N.3.SL.TZ0.15d: Outline how observers on Earth can determine experimentally the temperature of a distant star.
• 15N.3.SL.TZ0.16a: Show that this corresponds to a temperature around 3 K.
• 15N.3.SL.TZ0.16b: Suggest how the discovery of the CMB in the microwave region contradicts Newton’s assumption of...
• 14N.3.HL.TZ0.4a: Calculate the luminosity of Phi-1 Orionis in terms of the luminosity of the Sun. Assume that...
• 14N.3.HL.TZ0.4b: The Sun is expected to have a lifespan of around ${\text{1}}{{\text{0}}^{{\text{10}}}}$ years....
• 14N.3.HL.TZ0.4c.i: Using the HR diagram on page 6, draw the evolutionary path of Phi-1 Orionis as it leaves the main...
• 14N.3.HL.TZ0.4c.ii: Outline, with reference to the Oppenheimer–Volkoff limit, the fate of Phi-1 Orionis.
• 14N.3.HL.TZ0.5a: Estimate, in seconds, the age of the universe.
• 14N.3.HL.TZ0.5b: The wavelength of the lines in the absorption spectrum of hydrogen is 656.3 nm when measured on...
• 14N.3.SL.TZ0.14a: Distinguish between a stellar cluster and a constellation.
• 14N.3.SL.TZ0.15b.i: Describe the stellar parallax method.
• 14N.3.SL.TZ0.16b: In 1965, Penzias and Wilson discovered cosmic radiation with a wavelength that corresponded to a...
• 14M.3.HL.TZ2.4a: Achernar is a main sequence star with a mass that is eight times the mass of the Sun. Deduce that...
• 14M.3.HL.TZ2.4b: Outline why Achernar will spend less time on the main sequence than the Sun.
• 14M.3.HL.TZ2.4c: (i)     State the condition relating to mass that must be satisfied for Achernar to become a...
• 14M.3.HL.TZ2.5a: Suggest why the two wavelengths are different.
• 14M.3.HL.TZ2.5b: Determine the distance to this galaxy from Earth using a Hubble constant of...
• 14M.3.SL.TZ2.12a: State one difference between (i)     a main sequence star and a planet. (ii)     a stellar...
• 14M.3.SL.TZ2.12b: State how (i)     it is known that main sequence stars are made predominantly of...
• 14M.3.SL.TZ2.12c: The graph shows the variation with wavelength of the intensity of a main sequence...
• 14M.3.SL.TZ2.14a: State two characteristics of the cosmic microwave background (CMB) radiation.   1.       2.
• 14M.3.SL.TZ2.14b: Explain how CMB radiation is evidence for the Big Bang model of an expanding universe.
• 13M.3.SL.TZ1.14a: The peak in the radiation spectrum of a star X is at a wavelength of 300 nm. Show that the...
• 13M.3.SL.TZ1.14c: On the Hertzsprung–Russell diagram, label the position of star X with the letter X.  
• 13M.3.HL.TZ1.2c: On the Hertzsprung–Russell diagram, label (i) the position of star X with the letter X.(ii) the...
• 13M.3.HL.TZ1.2d: Explain, with reference to the Chandrasekhar limit, whether or not star X will become a white dwarf.
• 13M.3.HL.TZ1.5a: The fractional change in wavelength of the radio signals from galaxy A is 9.4×10–3. Calculate,...
• 13M.3.HL.TZ2.3a: The Hertzsprung–Russell (HR) diagram shows the Sun, a star A and the main sequence. Using the...
• 13M.3.HL.TZ2.3b: Star A will leave the main sequence and will evolve to become a neutron star. State the (i)...
• 13M.3.HL.TZ2.4a: State Hubble’s law.
• 13M.3.HL.TZ2.4b: Light from the galaxy M31 received on Earth shows a blue-shift corresponding to a fractional...
• 12M.3.SL.TZ1.13d: The distance to Naos may be determined by the method of stellar parallax. The diagram shows the...
• 12M.3.HL.TZ1.3a: (i) On the diagram above, draw a line to show the evolutionary path of the Sun from its present...
• 12M.3.HL.TZ1.3b: (i) Show that the mass of star X is approximately 14 solar masses. (Assume that n=3.5 in the...
• 12M.3.HL.TZ1.4a: State (i) Hubble’s law. (ii) the significance of the reciprocal of the Hubble constant.
• 12M.3.HL.TZ1.4b: The wavelength of a certain line in the hydrogen spectrum is measured to be 434 nm in the...
• 11M.3.SL.TZ2.14a: Describe what is meant by a (i) constellation. (ii) stellar cluster.
• 11M.3.SL.TZ2.14c: On the Hertzsprung–Russell diagram above, (i) label the position of Betelgeuse with the letter...
• 11M.3.HL.TZ2.3a: State what is meant by the (i) Chandrasekhar limit. (ii) Oppenheimer–Volkoff limit.
• 11M.3.HL.TZ2.3b: Suggest how your answers in (a) can be used to predict the fate of a main sequence star.
• 11M.3.HL.TZ2.4a: Outline the measurements that must be taken in order to determine a value for the Hubble constant.
• 11M.3.HL.TZ2.4b: One estimate of the Hubble constant is 60 km s–1 Mpc–1. Cygnus A is a radio galaxy at a distance...
• 11N.3.SL.TZ0.11a: On the grid of the Hertzsprung–Russell (HR) diagram shown, draw a line to represent the...
• 11N.3.SL.TZ0.11b: Barnard’s star is a main sequence star that is 1.8 pc from Earth. (i) Define the parsec. (ii)...
• 11N.3.SL.TZ0.11c: Outline, using your answer to (b)(ii) and a labelled diagram, how the distance of Barnard’s star...
• 11N.3.SL.TZ0.11d: The apparent brightness of Barnard’s star is 3.6×10–12Wm–2 and its surface temperature is 3800...
• 11N.3.SL.TZ0.12a: Light from distant galaxies, as seen by an observer on Earth, shows a red-shift. Outline why this...
• 11N.3.HL.TZ0.1e: On the HR diagram on page 2, draw the evolutionary path of Barnard’s star after it leaves the...
• 11N.3.HL.TZ0.3a: State Hubble’s law.
• 11N.3.HL.TZ0.3b: The wavelength of a line in the spectrum of atomic hydrogen, as measured in the laboratory, is...
• 12N.3.SL.TZ0.14b: Star A is part of a binary star system. The diagram shows the orbit of star A and the orbit of...
• 12N.3.SL.TZ0.14c: The diagram below shows the spectrum of the stars as observed from Earth. The spectrum shows one...
• 12N.3.SL.TZ0.15b: A Cepheid star and non-Cepheid star both belong to the same distant galaxy. Explain, stating the...
• 12N.3.SL.TZ0.16b: Outline one piece of experimental evidence that supports the fact that the universe is expanding.
• 12N.3.HL.TZ0.4a: A main sequence star has a mass of 2.2${M_ \odot }$ where ${M_ \odot }$=  1 solar mass. The...
• 12N.3.HL.TZ0.4b: The star in (a) will evolve to become a white dwarf. The diagram represents the stages in the...
• 12M.3.SL.TZ2.13a: Aldebaran is a red giant star in the constellation of Taurus. (i) Describe the differences...
• 12N.3.HL.TZ0.5a: The fractional change in the wavelength λ of light from the galaxy Hydra is...
• 12N.3.HL.TZ0.5b: An estimate of the age of the universe is $\frac{1}{H}$ where H is the Hubble constant. Suggest...
• 12M.3.SL.TZ2.13c: Distances to galaxies may be determined by using Cepheid variable stars. By considering the...
• 12M.3.HL.TZ2.1c: Betelgeuse in the constellation of Orion is a red supergiant star. (i) Compare the fate of...
• 12M.3.HL.TZ2.1d: Distances to galaxies may be determined by using Cepheid variable stars. By considering the...
• 12M.3.HL.TZ2.3a: State Hubble’s law.
• 12M.3.HL.TZ2.3b: Measured values of the Hubble constant can vary between 40 kms–1 Mpc–1 and 90 kms–1 Mpc–1. State...
• 12M.3.HL.TZ2.3c: The blue line in the spectrum of atomic hydrogen as measured in the laboratory is 490 nm. The...
• 13N.3.HL.TZ0.1f: On the HR diagram above, sketch the likely evolutionary path of Luyten’s star.
• 13N.3.HL.TZ0.3a: (i) On the axes, sketch a graph to show how the recessional speed v of a galaxy varies with...
• 13N.3.SL.TZ0.11e: Gomeisa, Luyten’s star and the Sun are main sequence stars. On the grid of the...
• 11M.3.SL.TZ1.14a: (i) Draw a circle around the stars that are red giants. Label this circle R. (ii) Draw a circle...
• 11M.3.SL.TZ1.14b: Explain, without doing any calculation, how astronomers can deduce that star B has a larger...
• 11M.3.SL.TZ1.14c: Using the following data and information from the HR diagram, show that star A is at a distance...
• 11M.3.SL.TZ1.14d: Explain why the distance of star A from Earth cannot be determined by the method of stellar...
• 11M.3.SL.TZ1.15a: State how the observed red-shift of many galaxies is explained.
• 11M.3.SL.TZ1.15b: Explain how the cosmic microwave background (CMB) radiation is consistent with the Big Bang model.
• 11M.3.SL.TZ1.15c: Calculate the temperature of the universe when the peak wavelength of the CMB was equal to the...
• 11M.3.HL.TZ1.4a: Assuming that the exponent n in the mass–luminosity relation is 3.5, show that the mass of Khad...
• 11M.3.HL.TZ1.4b: Outline the likely evolution of the star Khad after it leaves the main sequence.
• 11M.3.HL.TZ1.5a: (i) State Hubble’s law. (ii) State why Hubble’s law cannot be used to determine the distance...
• 11M.3.HL.TZ1.5b: (i) Show that $\frac{1}{{{H_0}}}$  is an estimate of the age of the universe, where H0 is the...
• 10N.3.HL.TZ0.E1i: The luminosity of the main sequence star Regulus is $150{\text{ }}{L_{\text{S}}}$. Assuming...
• 10N.3.HL.TZ0.E1j: (i)     other possible outcome of the final stage of the evolution of Betelgeuse. (ii)    ...
• 10N.3.HL.TZ0.E2c: Many galaxies are a great distance from Earth. Explain, with reference to Hubble’s law, how the...
• 10N.3.HL.TZ0.E2d: State one problem associated with using Hubble’s law to determine the distance of a galaxy a...
• 10N.3.SL.TZ0.E1a: The stars Procyon A and Procyon B are both located in the same stellar cluster in the...
• 10N.3.SL.TZ0.E2a: Describe what is meant by the Big Bang model.
• 10N.3.SL.TZ0.E2b: (i)     Explain how the CMB is consistent with the Big Bang model. (ii)     State why the...
• 16M.3.SL.TZ0.12a: Describe one key characteristic of a nebula.
• 16M.3.SL.TZ0.12b: Beta Centauri is a star in the southern skies with a parallax angle of 8.32×10−3 arc-seconds....
• 16M.3.SL.TZ0.12c: Outline why astrophysicists use non-SI units for the measurement of astronomical distance.
• 16M.3.SL.TZ0.13a: Show that the surface temperature of Aldebaran is about 4000 K.
• 16M.3.SL.TZ0.13b: The radius of Aldebaran is 3.1×1010 m. Determine the luminosity of Aldebaran.
• 16M.3.SL.TZ0.13c: Outline how the light from Aldebaran gives evidence of its composition.
• 16M.3.SL.TZ0.13d: Identify the element that is fusing in Aldebaran’s core at this stage in its evolution.
• 16M.3.SL.TZ0.13e: Predict the likely future evolution of Aldebaran.
• 16M.3.SL.TZ0.14a: Light reaching Earth from quasar 3C273 has z=0.16. (i) Outline what is meant by z. (ii)...
• 16M.3.SL.TZ0.14b: Explain how cosmic microwave background (CMB) radiation provides support for the Hot Big Bang model.
• 16M.3.HL.TZ0.17b: Beta Centauri is a star in the southern skies with a parallax angle of 8.32×10−3 arc-seconds....
• 16M.3.HL.TZ0.17c: Outline why astrophysicists use non-SI units for the measurement of astronomical distance.
• 16N.3.SL.TZ0.15a: State what is meant by a binary star system.
• 16N.3.SL.TZ0.15b: (i) Calculate...
• 16N.3.SL.TZ0.15c: Show, without calculation, that the radius of Alpha Centauri B is smaller than the radius of...
• 16N.3.SL.TZ0.15d: Alpha Centauri A is in equilibrium at constant radius. Explain how this equilibrium is maintained.
• 16N.3.SL.TZ0.15e: A standard Hertzsprung–Russell (HR) diagram is shown. Using the HR diagram, draw the present...
• 16N.3.SL.TZ0.16a: Determine the distance from Earth to the Cepheid star in parsecs. The luminosity of the Sun is...
• 16N.3.SL.TZ0.16b: Explain why Cephids are used as standard candles.
• 16N.3.SL.TZ0.17a: Identify two other characteristics of the CMB radiation that are predicted from the Hot Big Bang...
• 16N.3.SL.TZ0.17b: A spectral line in the hydrogen spectrum measured in the laboratory today has a wavelength of...
• 17M.3.SL.TZ1.9a.i: State what is meant by a main sequence star.
• 17M.3.SL.TZ1.9a.ii: Show that the mass of Theta 1 Orionis is about 40 solar masses.
• 17M.3.SL.TZ1.9a.iii: The surface temperature of the Sun is about 6000 K. Estimate the surface temperature of Theta 1...
• 17M.3.SL.TZ1.9a.iv: Determine the distance of Theta 1 Orionis in AU.
• 17M.3.SL.TZ1.9b: Discuss how Theta 1 Orionis does not collapse under its own weight.
• 17M.3.SL.TZ1.9c: The Sun and Theta 1 Orionis will eventually leave the main sequence. Compare and contrast the...
• 17M.3.SL.TZ1.10a.i: State two characteristics of the cosmic microwave background (CMB) radiation.
• 17M.3.SL.TZ1.10a.ii: The present temperature of the CMB is 2.8 K. Calculate the peak wavelength of the CMB.
• 17M.3.SL.TZ1.10b: Describe how the CMB provides evidence for the Hot Big Bang model of the universe.
• 17M.3.SL.TZ1.10c.i: Determine the distance to this galaxy using a value for the Hubble constant of H0 = 68 km...
• 17M.3.SL.TZ1.10c.ii: Estimate the size of the Universe relative to its present size when the light was emitted by the...
• 17M.3.SL.TZ2.11a: State the most abundant element in the core and the most abundant element in the outer layer.
• 17M.3.SL.TZ2.11b: The Hertzsprung–Russell (HR) diagram shows two main sequence stars X and Y and includes lines of...
• 17M.3.SL.TZ2.11c.i: On the HR diagram in (b), draw a line to indicate the evolutionary path of star X.
• 17M.3.SL.TZ2.11c.ii: Outline why the neutron star that is left after the supernova stage does not collapse under the...
• 17M.3.SL.TZ2.11c.iii: The radius of a typical neutron star is 20 km and its surface temperature is 106 K. Determine the...
• 17M.3.SL.TZ2.11c.iv: Determine the region of the electromagnetic spectrum in which the neutron star in (c)(iii) emits...
• 17M.3.SL.TZ2.12a: Describe what is meant by the Big Bang model of the universe.
• 17M.3.SL.TZ2.12b: State two features of the cosmic microwave background (CMB) radiation which are consistent with...
• 17M.3.SL.TZ2.12c.i: Determine the distance to the galaxy in Mpc.
• 17M.3.SL.TZ2.12c.ii: Describe how type Ia supernovae could be used to measure the distance to this galaxy.
• 17N.3.SL.TZ0.12d.i: Determine the radius of Sirius B in terms of the radius of the Sun.
• 17N.3.SL.TZ0.12d.ii: Identify the star type of Sirius B.
• 17N.3.SL.TZ0.12e.i: draw the approximate positions of Sirius A, labelled A and Sirius B, labelled B.
• 17N.3.SL.TZ0.12e.ii: sketch the expected evolutionary path for Sirius A.
• 17N.3.SL.TZ0.13a: Outline one reason for the difference in wavelength.
• 17N.3.SL.TZ0.13b: Determine the velocity of the galaxy relative to Earth.
• 18M.3.SL.TZ1.10a.i: Distinguish between the solar system and a galaxy.
• 18M.3.SL.TZ1.10a.ii: Distinguish between a planet and a comet. 
• 18M.3.SL.TZ1.11a.i: Suggest, using the graphs, why star X is most likely to be a main sequence star.
• 18M.3.SL.TZ1.11a.ii: Show that the temperature of star X is approximately 10 000 K.
• 18M.3.SL.TZ1.11b.i: Write down the luminosity of star X (LX) in terms of the luminosity of the Sun (Ls).
• 18M.3.SL.TZ1.11b.ii: Determine the radius of star X (RX) in terms of the radius of the Sun (Rs).
• 18M.3.SL.TZ1.11b.iii: Estimate the mass of star X (MX) in terms of the mass of the Sun (Ms).
• 18M.3.SL.TZ1.11c: Star X is likely to evolve into a stable white dwarf star. Outline why the radius of a white...
• 18M.3.SL.TZ1.12a: Explain how international collaboration has helped to refine this value.
• 18M.3.SL.TZ1.12b: Estimate, in Mpc, the distance between the galaxy and the Earth.
• 18M.3.SL.TZ2.11a: Main sequence stars are in equilibrium under the action of forces. Outline how this equilibrium...
• 18M.3.SL.TZ2.11b: A main sequence star P, is 1.3 times the mass of the Sun. Calculate the luminosity of P relative...
• 18M.3.SL.TZ2.11c.i: The luminosity of the Sun L$_ \odot$ is 3.85 × 1026 W. Determine the luminosity of...
• 18M.3.SL.TZ2.11c.ii: The distance to Gacrux can be determined using stellar parallax. Outline why this method is not...
• 18M.3.SL.TZ2.11d.i: draw the main sequence.
• 18M.3.SL.TZ2.11d.ii: plot the position, using the letter P, of the main sequence star P you calculated in (b).
• 18M.3.SL.TZ2.11d.iii: plot the position, using the letter G, of Gacrux.
• 18M.3.SL.TZ2.11e: Discuss, with reference to its change in mass, the evolution of star P from the main sequence...
• 18M.3.SL.TZ2.12a: Estimate, using the data, the age of the universe. Give your answer in seconds.
• 18M.3.SL.TZ2.12b: Identify the assumption that you made in your answer to (a).
• 18M.3.SL.TZ2.12c: On the graph, one galaxy is labelled A. Determine the size of the universe, relative to its...

Option D: Astrophysics (Additional higher level option topics)

• 15M.3.SL.TZ1.16b: Explain how the open and closed outcomes for the universe depend on the critical density of...
• 15M.3.SL.TZ1.16c: State one reason why it is difficult to determine the density of the universe.
• 15N.3.HL.TZ0.2e.i: Outline why the Sun will leave the main sequence, and describe the nuclear processes that occur...
• 15N.3.HL.TZ0.2e.ii: Describe two physical changes that the Sun will undergo as it enters the red giant stage.
• 13M.3.SL.TZ1.15a: (i) State what is meant by a standard candle. (ii) Outline the properties of a Cepheid star that...
• 11M.3.SL.TZ2.15a: Explain, with reference to the possible fate of the universe, the significance of the critical...
• 11M.3.SL.TZ2.15b: Suggest one reason why it is difficult to estimate the density of matter in the universe.
• 11N.3.SL.TZ0.12b: The future development of the universe is determined by the relationship between the apparent...
• 12N.3.SL.TZ0.16a: Theoretical studies indicate that the universe may be open, closed or flat. (i) State, by...
• 12M.3.SL.TZ2.14a: Define, with reference to the flat model of the universe, critical density.
• 12M.3.SL.TZ2.14b: The diagram represents how the universe might develop if its density were greater than the...
• 16M.3.HL.TZ0.20a: State the Jeans criterion for star formation.
• 16M.3.HL.TZ0.20b: Describe three differences between type Ia and type II supernovae.
• 16M.3.HL.TZ0.21a: On the axes, sketch a graph of the variation of cosmic scale factor with time for (i) a closed...
• 16M.3.HL.TZ0.21b: Explain one experimental observation that supports the presence of dark matter.
• 16N.3.HL.TZ0.24a: Describe how some white dwarf stars become type Ia supernovae.
• 16N.3.HL.TZ0.24b: Hence, explain why a type Ia supernova is used as a standard candle.
• 16N.3.HL.TZ0.24c: Explain how the observation of type Ia supernovae led to the hypothesis that dark energy exists.
• 16N.3.HL.TZ0.25a: Calculate the rotation velocity of stars 4.0 kpc from the centre of the galaxy. The average...
• 16N.3.HL.TZ0.25b: Explain why the rotation curves are evidence for the existence of dark matter.
• 17M.3.HL.TZ1.16a: Outline, with reference to star formation, what is meant by the Jeans criterion.
• 17M.3.HL.TZ1.16b: In the proton–proton cycle, four hydrogen nuclei fuse to produce one nucleus of helium releasing...
• 17M.3.HL.TZ1.16c: Massive stars that have left the main sequence have a layered structure with different chemical...
• 17M.3.HL.TZ1.17a: The graph shows the variation with time t of the cosmic scale factor R in the flat model of the...
• 17M.3.HL.TZ1.17b.i: The density of the observable matter in the universe is only 0.05 ρc. Suggest how the remaining...
• 17M.3.HL.TZ1.17b.ii: The density of dark energy is ρΛc2 where ρΛ = ρc – ρm. Calculate the amount of dark energy in 1...
• 17M.3.HL.TZ2.19a.i: Derive, using the concept of the cosmological origin of redshift, the relation T...
• 17M.3.HL.TZ2.19a.ii: The present temperature of the CMB is 2.8 K. This radiation was emitted when the universe was...
• 17M.3.HL.TZ2.19b: State how the anisotropies in the CMB distribution are interpreted.
• 17M.3.HL.TZ2.20a: Describe what is meant by dark matter.
• 17M.3.HL.TZ2.20b: The distribution of mass in a spherical system is such that the density ρ varies with distance...
• 17M.3.HL.TZ2.20c: Curve A shows the actual rotation curve of a nearby galaxy. Curve B shows the predicted rotation...
• 17N.3.HL.TZ0.20a: The Sun is a second generation star. Outline, with reference to the Jeans criterion (MJ), how the...
• 17N.3.HL.TZ0.20b: Suggest how fluctuations in the cosmic microwave background (CMB) radiation are linked to the...
• 17N.3.HL.TZ0.20c: Show that the critical density of the universe is $$\frac{{3{H^2}}}{{8\pi G}}$$ where H is the...
• 18M.3.HL.TZ1.18a: Describe the formation of a type Ia supernova.
• 18M.3.HL.TZ1.18b.i: Show that the distance to the supernova is approximately 3.1 × 1018 m.
• 18M.3.HL.TZ1.18b.ii: State one assumption made in your calculation.
• 18M.3.HL.TZ1.19a: The mass of visible matter in the galaxy is M. Show that for stars where r > R0 the velocity...
• 18M.3.HL.TZ1.19b: Draw on the axes the observed variation with r of the orbital speed v of stars in a galaxy.
• 18M.3.HL.TZ1.19c: Explain, using the equation in (a) and the graphs, why the presence of visible matter alone...
• 18M.3.HL.TZ2.18a: Outline, with reference to the Jeans criterion, why a cold dense gas cloud is more likely to form...
• 18M.3.HL.TZ2.18b: Explain how neutron capture can produce elements with an atomic number greater than iron.
• 18M.3.HL.TZ2.19a: Explain the evidence that indicates the location of dark matter in galaxies.
• 18M.3.HL.TZ2.19b: Outline why a hypothesis of dark energy has been developed.