# Topic Questions: 4 recall and use $\lambda = \frac{ax}{D}$ for double-slit interference using light — 9702 P1 Interference > 7 9702 P1 Interference topic questions (7 marks) on 4 recall and use … for double-slit interference… — 7 papers, 2025–2026. Open the exact question in the… - Canonical HTML: https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/interference/4-recall-and-use-lambda-frac-ax-d-for-double-slit-interference-using-light/ - Markdown mirror: https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/interference/4-recall-and-use-lambda-frac-ax-d-for-double-slit-interference-using-light/index.md --- CIE IAL · Physics · 9702 P1 · Interference 7 9702 P1 Interference topic questions are tagged to this syllabus point across 7 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. - 7 topic questions - 7 papers - 7 tagged marks - 58.3% of topic questions - 58.3% of topic marks - 2025–2026 - Syllabus 2025–2027 - [All 9702 P1 Interference topic questions](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/interference/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Interference syllabus point appears in 7 9702 P1 papers across 2025–2026, contributing 7 topic questions and 7 marks.** The most recent appearance is 9702/11 May/June 2026. That equals 58.3% of the 12 topic questions and 58.3% of the 12 marks tagged to Interference. 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-30) | **Q30** Double Slit Fringe Spacing Variation - CIE Physics 2026 Jun Paper 11 Q30 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=cc3bc1fb-5d32-4ebd-a007-75eca5050e6a&question_id=d74cc554-d72a-479b-9750-22490553a5fe&source_detail=9702%2F11+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-29) | **Q29** Double Slit Fringe Separation Calculation - CIE AS Physics 2026 Jun Paper 14 Q29 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=de063b94-8315-433b-9015-36c4298fd0da&question_id=8863f7a0-7eef-4134-8463-ecf8d30235e6&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-28) | **Q28** Double-Slit Interference Slit Separation - CIE Physics 2025 Nov Paper 11 Q28 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=924eca36-7f76-4bd9-bfca-c73eef3ca841&question_id=491e8f51-fe3b-4514-be7a-7dcb0904243d&source_detail=9702%2F11+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-28) | **Q28** Double-Slit Interference Fringe Spacing and Slit Separation - CIE AS Physics 2025 Winter Paper 13 Q28 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e008d23b-4651-402b-b889-f33aa055a6e8&question_id=8ed0af28-32c0-4487-ab9c-7eb1761eb874&source_detail=9702%2F13+October%2FNovember+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-31) | **Q31** Double-Slit Fringe Separation with Increased Screen Distance - CIE Physics 2025 Jun Paper 12 Q31 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b4660d66-a150-4696-975b-81801f6095c2&question_id=345110b7-cee1-422f-90ed-278b22bfddfc&source_detail=9702%2F12+May%2FJune+2025) | | [**9702/13** May/June 2025 · CIE IAL](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-1/2025-may-june-9702-13/#q-31) | **Q31** Factors Affecting Double-Slit Fringe Separation - CIE Physics 2025 Jun Paper 13 Q31 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=8b189094-c406-4e28-b27f-08421d7e7345&question_id=d4eb45ed-b4bc-40f0-9566-cd358188dc91&source_detail=9702%2F13+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-27) | **Q27** Fringe Separation in Double-Slit Interference - CIE Physics 2025 Jun Paper 14 Q27 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2106ff7e-11fe-46fe-a4ec-d7c6bb2b24c8&question_id=99661e07-4632-4d71-93db-b1263091b571&source_detail=9702%2F14+May%2FJune+2025) | ## Related topic questions in Interference - [1 understand the terms interference and coherence](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/interference/1-understand-the-terms-interference-and-coherence/) — 3 question items · 3 papers — 3 marks · 2025–2026 - [2 show an understanding of experiments that demonstrate two-source interference using water waves in a ripple tank, sound, light and microwaves](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/interference/2-show-an-understanding-of-experiments-that-demonstrate-two-source-interference-using/) — 1 question items · 1 papers — 1 marks · 2025 - [3 understand the conditions required if two-source interference fringes are to be observed](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/interference/3-understand-the-conditions-required-if-two-source-interference-fringes-are-to-be/) — 2 question items · 2 papers — 2 marks · 2025–2026 ## Topic question rules and edge cases **How many topic questions cover this syllabus point?** 7 question stems cover this subtopic across 7 papers, but only 7 tagged parts and 7 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/interference/4-recall-and-use-lambda-frac-ax-d-for-double-slit-interference-using-light/