plumiElectromagnetic radiation from stars: OCR A‑Level Physics A questions
Every OCR A-Level Physics A exam question on 5.5.2 Electromagnetic radiation from stars, 2016–2025, with its mark scheme and examiner’s report.
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Q1(b)
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Q21(a)(i)
The whole paper ↗![June 2024 Paper 1, question 21(a)(i): Use Fig. 21.1 to show that the surface temperature of Nu Persei is about 6300 K. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-jun24-21-ai-qp.webp?v=3)
Q21(a)(ii)
The whole paper ↗![June 2024 Paper 1, question 21(a)(ii): Estimate the radius of Nu Persei. radius = m [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-jun24-21-aii-qp.webp?v=3)
Q21(b)(ii)
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Q23(a)
The whole paper ↗![June 2024 Paper 1, question 23(a): An electron moves from energy level X to energy level Y. Show that the wavelength of the photon produced is about 410 nm. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-jun24-23-a-qp.webp?v=3)
Q23(b)(i)
The whole paper ↗![June 2024 Paper 1, question 23(b)(i): Explain the origin of the dark lines. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-jun24-23-bi-qp.webp?v=3)
Q22(a)
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Q4(b)(i)
The whole paper ↗![June 2022 Paper 3, question 4(b)(i): Suggest and explain how the spectrum might have looked in the distant past. You may draw on the figure to support your answer. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun22-04-bi-qp.webp?v=3)
Q23(b)(i)
The whole paper ↗![November 2021 Paper 1, question 23(b)(i): Define the luminosity of a star. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-nov21-23-bi-qp.webp?v=3)
Q23(b)(ii)
The whole paper ↗![November 2021 Paper 1, question 23(b)(ii): Use Stefan’s law to determine the ratio radius of star Aa2 radius of star Aa3 . ratio = [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-nov21-23-bii-qp.webp?v=3)
Q23(b)(iii)
The whole paper ↗![November 2021 Paper 1, question 23(b)(iii): Use Wien’s displacement law to explain which star would have the longest wavelength at the peak intensity of the emitted electromagnetic radiation. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-nov21-23-biii-qp.webp?v=3)
Q23(b)(iv)
The whole paper ↗![November 2021 Paper 1, question 23(b)(iv): Suggest how an astronomer using just an optical telescope can deduce that the three stars of Algol have different surface temperatures. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-nov21-23-biv-qp.webp?v=3)
Q23(b)(v)
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Q24(b)(i)
The whole paper ↗![November 2020 Paper 1, question 24(b)(i): Show that the surface temperature of Rigel is 12 000 K. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-nov20-24-bi-qp.webp?v=3)
Q24(b)(ii)
The whole paper ↗![November 2020 Paper 1, question 24(b)(ii): Calculate the radius of Rigel. radius = m [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-nov20-24-bii-qp.webp?v=3)
Q3(a)(i)
The whole paper ↗![November 2020 Paper 3, question 3(a)(i): Use the data below to show that the luminosity of the Sun is about 4 × 1026 W. radius of Sun = 7.0 × 108 m • • surface temperature of Sun = 5800 K [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-nov20-03-ai-qp.webp?v=3)
All 31 questions on Electromagnetic radiation from stars, as a list
- June 2025, Paper 1, Q13 (1 mark): The surface temperature of the Sun is 5800 K and the peak wavelength is 500 nm. What is the surface temperature, in K, of the star represented by the graph belo
- June 2025, Paper 1, Q21 (6 marks): 21* Analysis of stellar light can identify the elements that are present in the outer layers of a star. Absorption spectra of visible light collected from two m
- June 2025, Paper 3, Q1(b) (4 marks): A simplified energy level diagram for atomic oxygen is shown below. energy (eV) 0 –9.4 –11.7 –13.6 not to scale Determine the wavelength of the green light emit
- June 2024, Paper 1, Q21(a)(i) (2 marks): Use Fig. 21.1 to show that the surface temperature of Nu Persei is about 6300 K. [2]
- June 2024, Paper 1, Q21(a)(ii) (3 marks): Estimate the radius of Nu Persei. radius = m [3]
- June 2024, Paper 1, Q21(b)(ii) (4 marks): By the time the electromagnetic radiation from Nu Persei reaches Earth, the radiation from Nu Persei is evenly distributed over a spherical area with radius equ
- June 2024, Paper 1, Q23(a) (2 marks): An electron moves from energy level X to energy level Y. Show that the wavelength of the photon produced is about 410 nm. [2]
- June 2024, Paper 1, Q23(b)(i) (2 marks): Explain the origin of the dark lines. [2]
- June 2022, Paper 1, Q12 (1 mark): The diagram shows three energy levels X, Y and Z of an electron within a gas atom. –4.0 X energy / eV Y –6.0 Z –8.0 Which transition is correct when the electro
- June 2022, Paper 1, Q22(a) (2 marks): A team of astronomers have measurements to determine the peak surface temperature T and luminosity L of a distant star. They plan to use Stefan’s law to estimat
- June 2022, Paper 3, Q4(b)(i) (2 marks): Suggest and explain how the spectrum might have looked in the distant past. You may draw on the figure to support your answer. [2]
- November 2021, Paper 1, Q23(b)(i) (1 mark): Define the luminosity of a star. [1]
- November 2021, Paper 1, Q23(b)(ii) (2 marks): Use Stefan’s law to determine the ratio radius of star Aa2 radius of star Aa3 . ratio = [2]
- November 2021, Paper 1, Q23(b)(iii) (2 marks): Use Wien’s displacement law to explain which star would have the longest wavelength at the peak intensity of the emitted electromagnetic radiation. [2]
- November 2021, Paper 1, Q23(b)(iv) (1 mark): Suggest how an astronomer using just an optical telescope can deduce that the three stars of Algol have different surface temperatures. [1]
- November 2021, Paper 1, Q23(b)(v) (3 marks): The light from each star passing through a diffraction grating shows an absorption line spectrum. Explain how a specific absorption line is produced in this typ
- November 2020, Paper 1, Q6 (1 mark): The diagram below shows two energy levels for the electron in the hydrogen atom. energy / 10–19 J –1.36 photon –5.44 The electron makes the transition shown by
- November 2020, Paper 1, Q24(b)(i) (2 marks): Show that the surface temperature of Rigel is 12 000 K. [2]
- November 2020, Paper 1, Q24(b)(ii) (2 marks): Calculate the radius of Rigel. radius = m [2]
- November 2020, Paper 3, Q3(a)(i) (1 mark): Use the data below to show that the luminosity of the Sun is about 4 × 1026 W. radius of Sun = 7.0 × 108 m • • surface temperature of Sun = 5800 K [1]
- November 2020, Paper 3, Q3(a)(ii) (3 marks): Sirius, the brightest star in the night sky, has a luminosity 25 times greater than that of the Sun. It has diameter 1.7 times greater than that of the Sun. Cal
- June 2019, Paper 1, Q23(a) (6 marks): (a)* In 2017, an ultra-cool star TRAPPIST-1 was discovered with at least five of its own orbiting planets. Astronomers are interested about the possibility of f
- June 2019, Paper 3, Q5(a) (6 marks): In a semi-darkened room, a single slit is placed in front of the discharge tube. A student holds a diffraction grating which has 300 lines per millimetre. The s
- June 2019, Paper 3, Q5(b)(ii) (2 marks): Fig. 5.4 shows some of the energy levels of an electron in a hydrogen atom. E / 10–19 J –0.61 –0.87 –1.36 –2.42 –5.45 Fig. 5.4 (not to scale) Draw an arrow on F
- June 2018, Paper 1, Q8 (1 mark): An electron makes a transition between the two energy levels shown below. energy – 5.40 × 10–19 J photon X This transition produces a photon of frequency 4.10 ×
- June 2018, Paper 1, Q19(b)(i) (2 marks): Calculate the surface temperature of Beta Pictoris. temperature = K [2]
- June 2017, Paper 1, Q7 (1 mark): The intensity against wavelength graph of an object at 750 °C peaks at a wavelength of λ. The temperature of the object is raised to 960 °C. What is the wavelen
- June 2017, Paper 1, Q10 (1 mark): Part of the line spectrum for light from the Sun is shown below. Which spectrum best shows light from a similar star to the Sun? increasing wavelength spectrum
- June 2017, Paper 1, Q21(a)(i) (1 mark): Explain why the energy levels are negative. [1]
- June 2017, Paper 1, Q21(a)(ii) (4 marks): An electron makes a transition (jump) from level C to level A. 1 Calculate the energy gained by this electron. energy = eV [1] 2 Calculate the wavelength in nm
- June 2017, Paper 1, Q21(b)(i) (1 mark): State how an emission line is produced. [1]
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