# Topic Questions: 2 use the expression $f_o = \frac{f_s v}{v \pm v_s}$ for the observed frequency when a source of sound waves moves relative to a stationary observer — 9702 P1 Doppler effect for sound waves > 11 9702 P1 Doppler effect for sound waves topic questions (11 marks) on 2 use the expression … for the observed frequency… — 11 papers, 2025–2026. Open the… - Canonical HTML: https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/doppler-effect-for-sound-waves/2-use-the-expression-f-o-frac-f-s-v-v-pm-v-s-for-the-observed-frequency-when-a-source/ - Markdown mirror: https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/doppler-effect-for-sound-waves/2-use-the-expression-f-o-frac-f-s-v-v-pm-v-s-for-the-observed-frequency-when-a-source/index.md --- CIE IAL · Physics · 9702 P1 · Doppler effect for sound waves 11 9702 P1 Doppler effect for sound waves topic questions are tagged to this syllabus point across 11 papers (2025–2026). Only the parts whose knowledge graph matches this syllabus statement are counted, and the table shows which parts of each question are involved. - 11 topic questions - 11 papers - 11 tagged marks - 100.0% of topic questions - 100.0% of topic marks - 2025–2026 - Syllabus 2025–2027 - [All 9702 P1 Doppler effect for sound waves topic questions](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/doppler-effect-for-sound-waves/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Doppler effect for sound waves syllabus point appears in 11 9702 P1 papers across 2025–2026, contributing 11 topic questions and 11 marks.** The most recent appearance is 9702/11 May/June 2026. That equals 100.0% of the 11 topic questions and 100.0% of the 11 marks tagged to Doppler effect for sound waves. 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 | | --- | --- | --- | --- | --- | --- | --- | | [**9702/11** May/June 2026 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2026-may-june-9702-11/#q-24) | **Q24** Doppler Shift for Approaching Constant Velocity Source - CIE Physics 2026 Jun Paper 11 Q24 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=cc3bc1fb-5d32-4ebd-a007-75eca5050e6a&question_id=df0b698e-0242-475a-bd8e-208f79d666c5&source_detail=9702%2F11+May%2FJune+2026) | | [**9702/12** May/June 2026 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2026-may-june-9702-12/#q-24) | **Q24** Doppler Effect Velocity of Sound Source - CIE Physics 2026 Jun Paper 12 Q24 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=dff8c5d1-5de5-49c0-b417-97a49ecae26e&question_id=19e17d7d-a262-4908-bab4-befeb8348dff&source_detail=9702%2F12+May%2FJune+2026) | | [**9702/13** May/June 2026 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2026-may-june-9702-13/#q-24) | **Q24** Doppler Effect Observed Frequency - CIE Physics 2026 Jun Paper 13 Q24 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b1c6e9e0-2b9a-46bc-95ba-9424df870b39&question_id=f1d5188d-808e-4d2c-82ef-323f81f8a8a8&source_detail=9702%2F13+May%2FJune+2026) | | [**9702/14** May/June 2026 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2026-may-june-9702-14/#q-23) | **Q23** Doppler Effect Siren Frequencies Difference - CIE AS Physics 2026 Jun Paper 14 Q23 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=de063b94-8315-433b-9015-36c4298fd0da&question_id=baaf1327-da00-4a4d-86a6-44c56b14ef70&source_detail=9702%2F14+May%2FJune+2026) | | [**9702/11** October/November 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-october-november-9702-11/#q-27) | **Q27** Doppler Effect with Dolphin Sound - CIE Physics 2025 Nov Paper 11 Q27 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=924eca36-7f76-4bd9-bfca-c73eef3ca841&question_id=704842b8-7465-4966-9ba0-8dd24e2853db&source_detail=9702%2F11+October%2FNovember+2025) | | [**9702/12** October/November 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-october-november-9702-12/#q-27) | **Q27** Doppler Effect Sound Calculation - CIE AS Physics 2025 Nov Paper 12 Q27 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a9354265-4ad0-4b45-86d5-ea844b7fc508&question_id=00e96be2-40a2-4877-8118-e69156ac536e&source_detail=9702%2F12+October%2FNovember+2025) | | [**9702/13** October/November 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-october-november-9702-13/#q-27) | **Q27** Doppler Effect for Approaching Dolphin - CIE AS Physics 2025 Winter Paper 13 Q27 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e008d23b-4651-402b-b889-f33aa055a6e8&question_id=f207fe92-0796-4138-b208-8f50c7ee63db&source_detail=9702%2F13+October%2FNovember+2025) | | [**9702/14** October/November 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-october-november-9702-14/#q-27) | **Q27** Source Velocity from Doppler Shifted Frequency - CIE Physics 2025 Nov Paper 14 Q27 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=8d338983-d025-4544-9fad-eeb58b6137e4&question_id=d8358140-5d3c-46d7-82a4-58a8e789833d&source_detail=9702%2F14+October%2FNovember+2025) | | [**9702/11** May/June 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-may-june-9702-11/#q-24) | **Q24** Doppler Effect Speed and Direction of Aircraft - CIE AS Physics 2025 Jun Paper 11 Q24 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=325aa048-bfe6-485f-9b5e-526096d74ef8&question_id=f76b0712-c540-4ce7-9b7d-a8375ba4d779&source_detail=9702%2F11+May%2FJune+2025) | | [**9702/12** May/June 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-may-june-9702-12/#q-26) | **Q26** Maximum Doppler Frequency of Rotating Buzzer - CIE Physics 2025 Jun Paper 12 Q26 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b4660d66-a150-4696-975b-81801f6095c2&question_id=f869dcc1-1be4-4803-926a-770be1fca2fc&source_detail=9702%2F12+May%2FJune+2025) | | [**9702/14** May/June 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-may-june-9702-14/#q-22) | **Q22** Doppler Shift for Approaching Vehicle - CIE Physics 2025 Jun Paper 14 Q22 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2106ff7e-11fe-46fe-a4ec-d7c6bb2b24c8&question_id=0e926acd-fc7d-44af-b6a6-150b4a5bc5f9&source_detail=9702%2F14+May%2FJune+2025) | ## Related topic questions in Doppler effect for sound waves - [1 understand that when a source of sound waves moves relative to a stationary observer, the observed frequency is different from the source frequency (understanding of the Doppler effect for a stationary source and a moving observer is not required)](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/doppler-effect-for-sound-waves/1-understand-that-when-a-source-of-sound-waves-moves-relative-to-a-stationary/) — 5 question items · 5 papers — 5 marks · 2025–2026 ## Topic question rules and edge cases **How many topic questions cover this syllabus point?** 11 question stems cover this subtopic across 11 papers, but only 11 tagged parts and 11 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 2025–2026. 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/cie-ial/physics/9702-paper-1/doppler-effect-for-sound-waves/2-use-the-expression-f-o-frac-f-s-v-v-pm-v-s-for-the-observed-frequency-when-a-source/