# Topic Questions: 2 recall and use Malus’s law ($I = I_0 \cos^2\theta$) to calculate the intensity of a plane-polarised electromagnetic wave after transmission through a polarising filter or a series of polarising filters (calculation of the effect of a polarising filter on the intensity of an unpolarised wave is not required) — 9702 P1 Polarisation > 7 9702 P1 Polarisation topic questions (7 marks) on 2 recall and use Malus’s law (…) to calculate the… — 7 papers, 2025–2026. Open the exact question in the… - Canonical HTML: https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/polarisation/2-recall-and-use-malus-s-law-i-i-0-cos-2-theta-to-calculate-the-intensity-of-a-plane/ - Markdown mirror: https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/polarisation/2-recall-and-use-malus-s-law-i-i-0-cos-2-theta-to-calculate-the-intensity-of-a-plane/index.md --- CIE IAL · Physics · 9702 P1 · Polarisation 7 9702 P1 Polarisation 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 - 53.8% of topic questions - 53.8% of topic marks - 2025–2026 - Syllabus 2025–2027 - [All 9702 P1 Polarisation topic questions](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/polarisation/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Polarisation 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 53.8% of the 13 topic questions and 53.8% of the 13 marks tagged to Polarisation. 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-23) | **Q23** Angle of Polarising Filter via Malus's Law - CIE Physics 2026 Jun Paper 11 Q23 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=cc3bc1fb-5d32-4ebd-a007-75eca5050e6a&question_id=a2aae6c3-6700-4a30-a27c-091cd83f32a7&source_detail=9702%2F11+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-25) | **Q25** Successive Polarising Filters and Malus's Law - CIE Physics 2026 Jun Paper 13 Q25 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b1c6e9e0-2b9a-46bc-95ba-9424df870b39&question_id=0d1926c9-03d9-49f2-824c-13eb88251fa0&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-24) | **Q24** Malus's Law Intensity Variation with Angle - CIE AS Physics 2026 Jun Paper 14 Q24 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=de063b94-8315-433b-9015-36c4298fd0da&question_id=d97ba949-2649-4de1-82e6-f6497c43834c&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-26) | **Q26** Transmission Through Two Polarising Filters - CIE Physics 2025 Nov Paper 11 Q26 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=924eca36-7f76-4bd9-bfca-c73eef3ca841&question_id=52d901cc-31ed-4a4f-99d8-496f5e993e67&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-26) | **Q26** Light Intensity Through Two Polarising Filters - CIE AS Physics 2025 Winter Paper 13 Q26 | FRQ | 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e008d23b-4651-402b-b889-f33aa055a6e8&question_id=74adb1a6-4533-495b-8761-725dd7200c45&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-27) | **Q27** Malus's Law Intensity Reduction - CIE Physics 2025 Jun Paper 12 Q27 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b4660d66-a150-4696-975b-81801f6095c2&question_id=f7af0fc1-5b50-442d-a550-0ec888c79bca&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-24) | **Q24** Transmitted Intensity Using Malus's Law - CIE Physics 2025 Jun Paper 14 Q24 | FRQ | 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2106ff7e-11fe-46fe-a4ec-d7c6bb2b24c8&question_id=b15f4b0b-605d-4ef6-8cb6-4075371131eb&source_detail=9702%2F14+May%2FJune+2025) | ## Related topic questions in Polarisation - [1 understand that polarisation is a phenomenon associated with transverse waves](https://www.examsci.com/topics/cie-ial/physics/9702-paper-1/polarisation/1-understand-that-polarisation-is-a-phenomenon-associated-with-transverse-waves/) — 6 question items · 6 papers — 6 marks · 2025 ## 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/polarisation/2-recall-and-use-malus-s-law-i-i-0-cos-2-theta-to-calculate-the-intensity-of-a-plane/