# Topic Questions: 39 know and understand what is meant by wavefront, coherence, path difference, superposition, interference and phase — WPH12 Waves and Particle Nature of Light > 31 WPH12 Waves and Particle Nature of Light topic questions (91 marks) on 39 know and understand what is meant by… — 19 papers, 2019–2026. Open the exact… - Canonical HTML: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/ - Markdown mirror: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/index.md --- Edexcel IAL · Physics · WPH12 · Waves and Particle Nature of Light 31 WPH12 Waves and Particle Nature of Light topic questions are tagged to this syllabus point across 19 papers (2019–2026). Only the parts whose knowledge graph matches this syllabus statement are counted, and the table shows which parts of each question are involved. - 31 topic questions - 19 papers - 91 tagged marks - 6.6% of topic questions - 8.0% of topic marks - 2019–2026 - Syllabus 2018–current - [All WPH12 Waves and Particle Nature of Light topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Waves and Particle Nature of Light syllabus point appears in 19 WPH12 papers across 2019–2026, contributing 31 topic questions and 91 marks.** The most recent appearance is WPH12/01 January 2026. That equals 6.6% of the 468 topic questions and 8.0% of the 1,138 marks tagged to Waves and Particle Nature of Light. 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 | | --- | --- | --- | --- | --- | --- | --- | | [**WPH12/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2026-january-wph12-01/#q-17) | **Q17** Diffraction Grating Maxima - Edexcel IAL Physics Jan 2026 Q17 | FRQ | 1 of 2 parts ((b)) | 3 of 7 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=f217f3ed-8314-4b5a-a273-52fcc7614327&question_id=5f3cd812-c8be-4dc4-8074-45f7a77f8b0e&source_detail=WPH12%2F01+January+2026) | | [**WPH12/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2026-january-wph12-02/#q-19) | **Q19** Diffraction Grating and Wave Interference - Edexcel IAL Physics Jan 2026 Q19 | FRQ | 1 of 3 parts ((b)) | 3 of 9 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b8583b90-86ed-4ac4-a0d0-fbc38baea73c&question_id=ddc09e60-a8df-4e4f-89e2-79f922a8931e&source_detail=WPH12%2F02+January+2026) | | [**WPH12/01** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2025-october-wph12-01/#q-16) | **Q16** Coherence and Diffraction Grating - Edexcel IAL Physics Oct 2025 Q16 | FRQ | 2 of 5 parts ((a)(i), (a)(ii)) | 4 of 12 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=aca64168-b3d6-4595-86da-ac59e5bcce63&question_id=f0236fff-fe99-4a1c-b124-7acf60009109&source_detail=WPH12%2F01+October+2025) | | [**WPH12/01** June 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2025-june-wph12-01/#q-17) | **Q17** Stationary Waves in a Closed Tube - Edexcel IAL Physics May 2025 Q17 | FRQ | 1 of 3 parts ((a)) | 6 of 11 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3315043e-2e64-48db-9a4f-db8056c87e15&question_id=45291eed-da9e-4279-bf82-51867eb49256&source_detail=WPH12%2F01+June+2025) | | [**WPH12/01** January 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2025-january-wph12-01/#q-4) | **Q4** Wave Superposition on a String - Edexcel IAL Physics Jan 2025 Q4 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e619207f-bc85-4481-9d5b-1fbdc31ada66&question_id=f5b104c4-bc73-41d2-b717-edb63ea680b8&source_detail=WPH12%2F01+January+2025) | | [**WPH12/01** January 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2025-january-wph12-01/#q-7) | **Q7** Stationary Wave Phase and Amplitude - Edexcel IAL Physics Jan 2025 Q7 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e619207f-bc85-4481-9d5b-1fbdc31ada66&question_id=10c89650-2779-4d5e-a150-681e9679ce8e&source_detail=WPH12%2F01+January+2025) | | [**WPH12/01** January 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2025-january-wph12-01/#q-14) | **Q14** Diffraction Grating Maxima and Wave Nature - Edexcel IAL Physics Jan 2025 Q14 | FRQ | 1 of 3 parts ((b)(ii)) | 3 of 8 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e619207f-bc85-4481-9d5b-1fbdc31ada66&question_id=dcb0bdd2-f40e-4870-9880-0d7ac5f261cb&source_detail=WPH12%2F01+January+2025) | | [**WPH12/01** October 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2024-october-wph12-01/#q-13) | **Q13** Hologram Interference - Edexcel IAL Physics Oct 2024 Q13 | FRQ | 1 of 2 parts ((b)) | 3 of 4 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ed4e8373-fe1b-4450-b59f-13747d878e02&question_id=7f04c79a-3fd9-46cd-846f-b7afc032976a&source_detail=WPH12%2F01+October+2024) | | [**WPH12/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2024-january-wph12-01/#q-11) | **Q11** Laser Coherence and Standing Waves - Edexcel IAL Physics Jan 2024 Q11 | FRQ | 1 of 2 parts ((a)) | 1 of 2 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=030444a8-988a-46b6-9902-c76464e7c5f1&question_id=4e911116-117b-411d-87a9-18ee198b147c&source_detail=WPH12%2F01+January+2024) | | [**WPH12/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2024-january-wph12-01/#q-17) | **Q17** Harbour Wave Diffraction and Interference - Edexcel IAL Physics Jan 2024 Q17 | FRQ | 1 of 2 parts ((b)) | 6 of 8 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=030444a8-988a-46b6-9902-c76464e7c5f1&question_id=f6fd78e6-8c7f-4ac6-ad14-4fd082740f04&source_detail=WPH12%2F01+January+2024) | | [**WPH12/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2023-october-wph12-01/#q-7) | **Q7** Stationary Wave Phase Relationships - Edexcel IAL Physics Oct 2023 Q7 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3e216bad-b45b-4b54-ad64-443f4188aa4c&question_id=7edd4b4c-0ec4-4325-81bc-551cafa16ef6&source_detail=WPH12%2F01+October+2023) | | [**WPH12/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2023-october-wph12-01/#q-16) | **Q16** Solar Cell Thin Coating and Efficiency - Edexcel IAL Physics Oct 2023 Q16 | FRQ | 1 of 3 parts ((a)) | 3 of 11 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3e216bad-b45b-4b54-ad64-443f4188aa4c&question_id=7b61fa25-b1fc-4b7d-a3dd-bcbb0063c82f&source_detail=WPH12%2F01+October+2023) | | [**WPH12/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2023-october-wph12-01/#q-18) | **Q18** Snell's Law, Wavefronts and Critical Angle - Edexcel IAL Physics Oct 2023 Q18 | FRQ | 1 of 4 parts ((a)) | 4 of 14 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3e216bad-b45b-4b54-ad64-443f4188aa4c&question_id=83d8c60c-f85b-4562-81fb-2ffe50f6d30b&source_detail=WPH12%2F01+October+2023) | | [**WPH12/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2023-june-wph12-01/#q-7) | **Q7** Coherent Waves Definition - Edexcel IAL Physics May 2023 Q7 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3a8e11e5-0ef0-468b-b140-32d6d8e746b5&question_id=e7e8f04c-117d-426c-b608-2e476ac83e87&source_detail=WPH12%2F01+June+2023) | | [**WPH12/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2023-january-wph12-01/#q-15) | **Q15** Interference and Coherence - Edexcel IAL Physics Jan 2023 Q15 | FRQ | 2 parts ((a), (b)) | 8 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=44f43e47-e4db-4cf8-926d-d8e4e0a15c3a&question_id=c656cfee-eb8e-491e-a975-4c8080731d77&source_detail=WPH12%2F01+January+2023) | | [**WPH12/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2022-october-wph12-01/#q-11) | **Q11** Electron Diffraction Evidence - Edexcel IAL Physics Oct 2022 Q11 | FRQ | 1 part | 3 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=beffb6bb-3877-4d0b-b853-45356f31e525&question_id=b50603d1-4c0d-4b22-b128-c73f6c98de36&source_detail=WPH12%2F01+October+2022) | | [**WPH12/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2022-october-wph12-01/#q-15) | **Q15** Superposition of Sound Waves and Stationary Waves on a Wire - Edexcel IAL Physics Oct 2022 Q15 | FRQ | 1 of 3 parts ((a)(ii)) | 6 of 12 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=beffb6bb-3877-4d0b-b853-45356f31e525&question_id=500d31eb-d382-4f32-8529-bac991e6c5c0&source_detail=WPH12%2F01+October+2022) | | [**WPH12/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2022-june-wph12-01/#q-14) | **Q14** Earthquake Waves: Wave Speed, Coherence and Interference - Edexcel IAL Physics June 2022 Q14 | FRQ | 2 of 4 parts ((b)(i), (b)(ii)) | 5 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3069ad40-1aa5-4af5-a2d4-5c7bfc121c7d&question_id=0e9ea5ed-915d-4032-9896-8c64f81c3a96&source_detail=WPH12%2F01+June+2022) | | [**WPH12/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2022-january-wph12-01/#q-14) | **Q14** Diffraction Grating Laser Wavelength Analysis - Edexcel IAL Physics Jan 2022 Q14 | FRQ | 1 of 3 parts ((b)) | 3 of 9 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=272cf6d5-ace3-46e9-81c3-821d84b7c606&question_id=a69ef3d9-d754-40e9-ba6c-1c8373d0d09c&source_detail=WPH12%2F01+January+2022) | | [**WPH12/01** October 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2021-october-wph12-01/#q-7) | **Q7** Microwave Interference in Oven - Edexcel IAL Physics Oct 2021 Q7 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a6a4d67e-15cf-4c88-8068-dbcf14bb868f&question_id=7b6156c0-1915-4a2b-955c-607985c1b253&source_detail=WPH12%2F01+October+2021) | | [**WPH12/01** June 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2021-june-wph12-01/#q-10) | **Q10** Constructive Interference - Edexcel IAL Physics June 2021 Q10 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1edbe5c1-050a-47b1-b2d3-6cb7932da279&question_id=3f52caef-c998-42e2-ad70-25213273733d&source_detail=WPH12%2F01+June+2021) | | [**WPH12/01** June 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2021-june-wph12-01/#q-17) | **Q17** Speed of Sound in Air - Edexcel IAL Physics June 2021 Q17 | FRQ | 2 parts ((a), (b)) | 8 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1edbe5c1-050a-47b1-b2d3-6cb7932da279&question_id=df394960-6dea-4450-acd4-48758f8f2a35&source_detail=WPH12%2F01+June+2021) | | [**WPH12/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2021-january-wph12-01/#q-12) | **Q12** Superposition in Ripple Tank - Edexcel IAL Physics Jan 2021 Q12 | FRQ | 1 part | 4 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=0685a005-c20b-4099-9db0-869cf6f6e4cf&question_id=3270e6d4-58b0-4637-af31-00946c832a10&source_detail=WPH12%2F01+January+2021) | | [**WPH12/01** October 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2020-october-wph12-01/#q-13) | **Q13** Active Noise Reduction Systems - Edexcel IAL Physics Oct 2020 Q13 | FRQ | 1 of 2 parts ((b)) | 6 of 9 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=30b9f85f-384f-48e3-b52d-af344e695501&question_id=6f8fcf60-e582-43ec-98fe-a7ff97836f23&source_detail=WPH12%2F01+October+2020) | | [**WPH12/01** January 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2020-january-wph12-01/#q-1) | **Q1** Constructive Interference - Edexcel IAL Physics Jan 2020 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=68c06fc7-b8d0-47b8-8712-5b4ad068842c&question_id=0397c354-9247-41a8-94d3-2f37efac6a7b&source_detail=WPH12%2F01+January+2020) | | [**WPH12/01** June 2019 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2019-june-wph12-01/#q-17) | **Q17** Two-Source Interference of Sound Waves - Edexcel IAL Physics May 2019 Q17 | FRQ | 2 of 4 parts ((a), (c)) | 5 of 12 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ac1ff5b2-f21b-4af1-906c-a87572cb18c1&question_id=0baeea2b-477f-426b-a89e-8f9716337203&source_detail=WPH12%2F01+June+2019) | ## Related topic questions in Waves and Particle Nature of Light - [33 understand the terms amplitude, frequency, period, speed and wavelength](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/33-understand-the-terms-amplitude-frequency-period-speed-and-wavelength/) — 21 question items · 14 papers — 37 marks · 2019–2026 - [34 be able to use the wave equation $v=f\lambda$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/34-be-able-to-use-the-wave-equation-v-f-lambda/) — 36 question items · 19 papers — 117 marks · 2019–2026 - [35 be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/35-be-able-to-describe-longitudinal-waves-in-terms-of-pressure-variation-and-the/) — 10 question items · 9 papers — 15 marks · 2019–2026 - [36 be able to describe transverse waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/36-be-able-to-describe-transverse-waves/) — 11 question items · 10 papers — 20 marks · 2019–2026 - [37 be able to draw and interpret graphs representing transverse and longitudinal waves including standing/stationary waves](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/37-be-able-to-draw-and-interpret-graphs-representing-transverse-and-longitudinal/) — 22 question items · 14 papers — 47 marks · 2019–2026 - [38 CORE PRACTICAL 4: Determine the speed of sound in air using a 2-beam oscilloscope, signal generator, speaker and microphone](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/waves-and-particle-nature-of-light/38-core-practical-4-determine-the-speed-of-sound-in-air-using-a-2-beam-oscilloscope/) — 8 question items · 5 papers — 25 marks · 2019–2024 ## Topic question rules and edge cases **How many topic questions cover this syllabus point?** 26 question stems cover this subtopic across 19 papers, but only 31 tagged parts and 91 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 2019–2026. 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-2-wph12/waves-and-particle-nature-of-light/39-know-and-understand-what-is-meant-by-wavefront-coherence-path-difference/