# Topic Questions: 162 be able to use the Stefan-Boltzmann law equation $L=\sigma AT^{4}$ for black body radiators — WPH15 Astrophysics and Cosmology > 23 WPH15 Astrophysics and Cosmology topic questions (79 marks) on 162 be able to use the Stefan-Boltzmann law… — 20 papers, 2020–2026. Open the exact… - Canonical HTML: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/162-be-able-to-use-the-stefan-boltzmann-law-equation-l-sigma-at-4-for-black-body/ - Markdown mirror: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/162-be-able-to-use-the-stefan-boltzmann-law-equation-l-sigma-at-4-for-black-body/index.md --- Edexcel IAL · Physics · WPH15 · Astrophysics and Cosmology 23 WPH15 Astrophysics and Cosmology topic questions are tagged to this syllabus point across 20 papers (2020–2026). Only the parts whose knowledge graph matches this syllabus statement are counted, and the table shows which parts of each question are involved. - 23 topic questions - 20 papers - 79 tagged marks - 7.6% of topic questions - 10.9% of topic marks - 2020–2026 - Syllabus 2018–current - [All WPH15 Astrophysics and Cosmology topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Astrophysics and Cosmology syllabus point appears in 20 WPH15 papers across 2020–2026, contributing 23 topic questions and 79 marks.** The most recent appearance is WPH15/01 January 2026. That equals 7.6% of the 303 topic questions and 10.9% of the 725 marks tagged to Astrophysics and Cosmology. Only parts tagged to this subtopic are counted, so a four-part question can contribute one item and one part's marks. The table lists every matching question, its tagged parts and marks, with a link back to the paper page. Sessions are newest first, so the statement can be traced back through the full paper history. ## Topic questions by session Newest sessions first. Parts and marks count only the parts tagged to this subtopic; “x of y parts” shows how much of the question is tagged elsewhere. Select the paper cell to open the matching question on the paper page, or use **Go to Practice Hub** to answer that exact question in the Interactive Practice Hub. | Paper | Question | Type | Parts | Marks | Difficulty | Practice | | --- | --- | --- | --- | --- | --- | --- | | [**WPH15/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2026-january-wph15-01/#q-18) | **Q18** Exoplanets and Stellar Characteristics of Trappist-1 - Edexcel IAL Physics Jan 2026 Q18 | FRQ | 1 of 6 parts ((a)(i)) | 4 of 14 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=33df4133-3f97-49c4-8770-848b232eb7b1&question_id=065e9f95-d8d2-45bf-994f-5caa08dae9a0&source_detail=WPH15%2F01+January+2026) | | [**WPH15/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2026-january-wph15-02/#q-21) | **Q21** Stellar Radiation Curves and Wien's Law - Edexcel IAL Physics Jan 2026 Q21 | FRQ | 1 of 4 parts ((a)(iii)) | 1 of 5 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=f63db731-6514-40da-90c9-5232288471cb&question_id=e673f89c-a70d-4f75-8084-ebb518973238&source_detail=WPH15%2F02+January+2026) | | [**WPH15/01** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2025-october-wph15-01/#q-18) | **Q18** Astrophysics - H-R Diagram and Star Clusters - Edexcel IAL Physics Oct 2025 Q18 | FRQ | 1 of 4 parts ((b)(i)) | 5 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a7fbae2d-76be-4ac0-9bd4-df3ed119c92f&question_id=efcad81a-398f-4b0c-bc2b-ddbb6adcdda1&source_detail=WPH15%2F01+October+2025) | | [**WPH15/02** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2025-october-wph15-02/#q-18) | **Q18** Hertzsprung-Russell (H-R) Diagram and Arcturus - Edexcel IAL Physics Oct 2025 Q18 | FRQ | 1 of 4 parts ((b)(i)) | 5 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e7442241-a09d-4872-a697-6e37dca804e8&question_id=850b616f-b75e-4fe3-9bd9-6e8c678fa4d4&source_detail=WPH15%2F02+October+2025) | | [**WPH15/01** June 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2025-june-wph15-01/#q-19) | **Q19** Tau Ceti Stellar Properties - Edexcel IAL Physics June 2025 Q19 | FRQ | 1 of 3 parts ((b)) | 5 of 10 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2e30fb2a-dfff-4c32-b30f-fefebd92c451&question_id=651f39be-77ce-4602-99a7-eeef7fe1d9b8&source_detail=WPH15%2F01+June+2025) | | [**WPH15/01** January 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2025-january-wph15-01/#q-19) | **Q19** Argon Bulb Gas Laws and Filament Black Body - Edexcel IAL Physics Jan 2025 Q19 | FRQ | 1 of 4 parts ((c)(i)) | 3 of 10 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=40c335c3-e98a-43c8-b5d1-d1abedfaca1a&question_id=5a7c1ffc-256e-4695-bb6d-9ce796d371d1&source_detail=WPH15%2F01+January+2025) | | [**WPH15/01** October 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2024-october-wph15-01/#q-15) | **Q15** Edexcel IAL Physics Unit 5 Oct 2024 Q15 | FRQ | 1 of 2 parts ((a)) | 3 of 7 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3e10632c-bdcc-44a6-afc4-5f4f7a30978e&question_id=069e0eeb-0766-4fbe-b129-730c8355517e&source_detail=WPH15%2F01+October+2024) | | [**WPH15/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2024-june-wph15-01/#q-16) | **Q16** Epsilon-Eridani Radiation and Doppler Shift - Edexcel IAL Physics Unit 5 Jun 2024 Q16 | FRQ | 1 of 2 parts ((a)) | 5 of 8 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=fd4de767-0a74-4fd7-9f81-6fb7daf58d01&question_id=11cd64f5-49f2-4455-b234-7ac96b2ee4fb&source_detail=WPH15%2F01+June+2024) | | [**WPH15/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2024-june-wph15-01/#q-19) | **Q19** Nuclear Fusion in Stars & Life Cycle - Edexcel IAL Physics Unit 5 Jun 2024 Q19 | FRQ | 1 of 3 parts ((a)(ii)) | 5 of 15 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=fd4de767-0a74-4fd7-9f81-6fb7daf58d01&question_id=8abec1a1-fb49-4713-a72c-80feff76f1f8&source_detail=WPH15%2F01+June+2024) | | [**WPH15/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2024-january-wph15-01/#q-16) | **Q16** Astrophysics and Cosmology - Edexcel IAL Physics Jan 2024 Q16 | FRQ | 1 of 2 parts ((a)) | 4 of 8 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=81ae8d95-9845-43d2-85aa-56edeba0f606&question_id=64c1601b-9da3-4370-8bb6-ad8225469ac2&source_detail=WPH15%2F01+January+2024) | | [**WPH15/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2023-october-wph15-01/#q-21) | **Q21** Stellar Evolution and Mechanics of Betelgeuse - Edexcel IAL Physics Oct 2023 Q21 | FRQ | 1 of 4 parts ((a)(i)) | 4 of 13 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=c6d9493b-ab37-4b2a-967c-30f17fd52e71&question_id=20110155-de90-4b23-8957-730987f13d6f&source_detail=WPH15%2F01+October+2023) | | [**WPH15/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2023-june-wph15-01/#q-21) | **Q21** Edexcel IAL Physics Unit 5 June 2023 Q21 | FRQ | 1 of 3 parts ((a)(ii)) | 5 of 11 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=25ca8d3d-f529-419a-8ab4-22f4c43251b4&question_id=6302d228-3a1a-44a0-a16e-4d87fda2c645&source_detail=WPH15%2F01+June+2023) | | [**WPH15/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2023-january-wph15-01/#q-21) | **Q21** Kapteyn's Star and Planet Kapteyn-b - Edexcel IAL Physics Jan 2023 Q21 | FRQ | 1 of 3 parts ((a)(ii)) | 4 of 11 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=79fd249d-5274-48b7-a2fe-e660c6fd21a0&question_id=dd24c0e0-aefb-48a0-a58a-9a76d44e0c3a&source_detail=WPH15%2F01+January+2023) | | [**WPH15/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-october-wph15-01/#q-16) | **Q16** Stellar Characteristics of Gliese-876 - Edexcel IAL Physics Oct 2022 Q16 | FRQ | 1 of 2 parts ((b)) | 4 of 8 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=11a7a1e1-92c0-4c27-923f-84fabaf236e5&question_id=54ed7bc5-a49e-4f31-bb2a-bfede028ee1f&source_detail=WPH15%2F01+October+2022) | | [**WPH15/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-june-wph15-01/#q-18) | **Q18** Wolf 359 Parallax, Surface Temperature and Luminosity - Edexcel IAL Physics Jun 2022 Q18 | FRQ | 1 of 4 parts ((b)(ii)) | 3 of 10 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9a093fb4-7c1b-4987-9e36-33b3e20c2b25&question_id=df468d2a-17d3-45b3-ad51-45d46434d063&source_detail=WPH15%2F01+June+2022) | | [**WPH15/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-june-wph15-01/#q-19) | **Q19** Mercury Atoms Spectrum and Star Chi Lupi Properties - Edexcel IAL Physics Jun 2022 Q19 | FRQ | 1 of 3 parts ((c)) | 1 of 8 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9a093fb4-7c1b-4987-9e36-33b3e20c2b25&question_id=daaa8595-95a7-4058-870a-5787a341ac7e&source_detail=WPH15%2F01+June+2022) | | [**WPH15/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-january-wph15-01/#q-15) | **Q15** Procyon Black Body Radiation - Edexcel IAL Physics Jan 2022 Q15 | FRQ | 1 part | 5 | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ba0935d7-8bd2-4880-a14a-07ef68b24285&question_id=5051a761-4d96-4a0f-8dc2-146c6bc92bf0&source_detail=WPH15%2F01+January+2022) | | [**WPH15/02** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-january-wph15-02/#q-21) | **Q21** Solar Power on Mars and Solar Radius - Edexcel IAL Physics Jan 2022 Q21 | FRQ | 1 of 3 parts ((b)) | 4 of 10 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=23304130-a638-4c40-b130-1921931842df&question_id=7f8130ef-42b2-407a-9148-d71032715266&source_detail=WPH15%2F02+January+2022) | | [**WPH15/01** October 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2021-october-wph15-01/#q-20) | **Q20** Evolution of the Sun - Edexcel IAL Physics Oct 2021 Unit 5 Q20 | FRQ | 2 of 5 parts ((b)(i), (b)(ii)) | 5 of 12 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=85f00adf-61bf-4290-b7e1-556838a91d6f&question_id=f1867e3f-b3a0-422e-8984-81e95541254e&source_detail=WPH15%2F01+October+2021) | | [**WPH15/01** June 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2021-june-wph15-01/#q-8) | **Q8** Stellar Luminosity and Surface Temperature - Edexcel IAL Physics Jun 2021 Q8 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ab093dfb-339d-4a8a-9997-6d539dfdc6b8&question_id=4d16cbb5-7b47-487f-8ec9-62765320d550&source_detail=WPH15%2F01+June+2021) | | [**WPH15/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2021-january-wph15-01/#q-8) | **Q8** Astrophysics - star luminosity ratio | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2e0b1233-9e48-4222-bc71-6c120258396f&question_id=2833f41d-3a7e-4522-8b4f-6412fd6945de&source_detail=WPH15%2F01+January+2021) | | [**WPH15/01** October 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2020-october-wph15-01/#q-16) | **Q16** Stellar Characteristics of Alnilam and Mintaka - Edexcel IAL Physics Oct 2020 Q16 | FRQ | 1 of 4 parts ((c)) | 2 of 8 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=9c163041-4c0e-4b71-9ff8-11ee50a56f52&source_detail=WPH15%2F01+October+2020) | ## Related topic questions in Astrophysics and Cosmology - [154 understand that a gravitational field (force field) is defined as a region where a mass experiences a force](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/154-understand-that-a-gravitational-field-force-field-is-defined-as-a-region-where-a/) — 5 question items · 4 papers — 13 marks · 2021–2026 - [155 understand that gravitational field strength is defined as $g=\frac{F}{m}$ and be able to use this equation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/155-understand-that-gravitational-field-strength-is-defined-as-g-frac-f-m-and-be-able/) — 5 question items · 5 papers — 12 marks · 2020–2026 - [156 be able to use the equation $F=\frac{Gm_{1}m_{2}}{r^{2}}$ (Newton's law of universal gravitation)](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/156-be-able-to-use-the-equation-f-frac-gm-1-m-2-r-2-newton-s-law-of-universal/) — 24 question items · 15 papers — 62 marks · 2020–2026 - [157 be able to derive and use the equation $g=\frac{Gm}{r^{2}}$ for the gravitational field due to a point mass](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/157-be-able-to-derive-and-use-the-equation-g-frac-gm-r-2-for-the-gravitational-field/) — 23 question items · 18 papers — 50 marks · 2020–2026 - [158 be able to use the equation $V_{grav}=\frac{-Gm}{r}$ for a radial gravitational field](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/158-be-able-to-use-the-equation-v-grav-frac-gm-r-for-a-radial-gravitational-field/) — 29 question items · 19 papers — 61 marks · 2020–2026 - [159 be able to compare electric fields with gravitational fields](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/159-be-able-to-compare-electric-fields-with-gravitational-fields/) — 5 question items · 5 papers — 11 marks · 2020–2025 ## Topic question rules and edge cases **How many topic questions cover this syllabus point?** 22 question stems cover this subtopic across 20 papers, but only 23 tagged parts and 79 marks belong to it. Other parts of the same questions are assessed under different statements and are excluded from this page. **Which papers include this subtopic?** The table lists every matching session from 2020–2026. Each row links to the question anchor on the paper page, where the full paper context and practice entry point are available. **Why can one question appear under several subtopics?** The parts of one question can assess different syllabus statements. Each part is counted under its own subtopics, so the same question stem can appear on several subtopic pages while each page lists only the parts and marks tagged to that statement. **Can I practise these questions with AI marking?** Yes. Open a paper from the table and use the Interactive Practice Hub entry point. The page itself is static HTML so search engines and retrieval agents can read the full question list without executing JavaScript. --- Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/162-be-able-to-use-the-stefan-boltzmann-law-equation-l-sigma-at-4-for-black-body/