# WPH15/01 October 2020 > WPH15/01 October 2020: 20 questions, 90 marks. Difficulty 0.42, deviation 0.18, algebraic 0.30, text density 0.36. Edexcel IAL Physics U5. - Canonical HTML: https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2020-october-wph15-01/ - Markdown mirror: https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2020-october-wph15-01/index.md --- Edexcel IAL · Physics · 2020 October This Physics Unit 5 (WPH15) paper contains 20 questions worth 90 marks. The profile below reports five mark-weighted difficulty and complexity measures, and every question row repeats them. Full question text and mark scheme open in the Interactive Practice Hub. - Edexcel IAL - U5 - 20 questions - 90 marks - Free paper - [Practise this paper](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6) - [All U5 papers](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/) Core finding **WPH15/01 October 2020 is a past paper for Edexcel IAL Physics Unit 5 (WPH15), with 20 questions worth 90 marks.** Its mark-weighted Difficulty Measure is 0.42 on a 0.20–0.75 scale, with a Difficulty Deviation of 0.18 and a mark split of 28.9% Easy, 52.2% Medium and 18.9% Hard. Algebraic complexity averages 0.30; text density and modelling average 0.36. All five measures use 39 part-level tags, not candidate results. Every question row below repeats them and opens the Interactive Practice Hub for that question. ## Difficulty & complexity profile All five measures are mark-weighted and calculated from 39 parts carrying 90 part marks. Difficulty tags cover 39 parts, algebraic tags 39 and text-density tags 39. Tags are internal metadata, not official exam-board ratings. - **Difficulty Measure**: 0.42 — 0.20–0.75 · nearer Medium - **Difficulty Deviation**: 0.18 — 0 = uniform; higher = more mixed - **Difficulty Ratio**: 28.9 / 52.2 / 18.9 — % Easy / Medium / Hard - **Algebraic Complexity Measure**: 0.30 — 0.20–0.75 · nearer Low - **Text Density and Modelling Measure**: 0.36 — 0.20–0.75 · nearer Medium Scale: Easy 0.20 · Medium 0.45 · Hard 0.75, and Low 0.20 · Medium 0.45 · High 0.75 for the two complexity measures. [How each band is defined and how the values are calculated →](https://www.examsci.com/guides/difficulty-and-complexity-measures/) ### Definitions and calculation | Measure | Paper value | Formula | | --- | --- | --- | | **Difficulty Measure** | 0.42 | Σ(d_i × w_i) / Σw_i, with d = 0.20 / 0.45 / 0.75 | | **Difficulty Deviation** | 0.18 | √(Σw_i(d_i − μ)^2 / Σw_i) | | **Difficulty Ratio** | 28.9% Easy / 52.2% Medium / 18.9% Hard | marks in band / all tagged marks | | **Algebraic Complexity Measure** | 0.30 | Σ(c_i × marks_i) / Σmarks_i, with c = 0.20 / 0.45 / 0.75 | | **Text Density and Modelling Measure** | 0.36 | Σ(t_i × marks_i) / Σmarks_i, with t = 0.20 / 0.45 / 0.75 | w_i equals the part marks, except for a Hard part worth 4 or more marks, where w_i = marks^0.75 to offset the accessible starter steps inside long structured questions. ## Question list Each measure is recalculated from the parts of that question and uses the same weights as the paper profile. | Question | Topic | Marks | Difficulty Measure | Algebraic Complexity Measure | Text Density and Modelling Measure | Practice | | --- | --- | --- | --- | --- | --- | --- | | **Q1** MCQ | [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) | 1 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=25cd1144-ab75-411d-98d5-29210ce2a485&source_detail=WPH15%2F01+October+2020) | | **Q2** MCQ | [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) | 1 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=8a99fe7a-ecdc-48e5-bcbf-adac004504c3&source_detail=WPH15%2F01+October+2020) | | **Q3** MCQ | [U5 Thermodynamics](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/thermodynamics/) | 1 | 0.45 Medium | 0.45 Medium | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=4260bad6-fd2b-4394-97f0-46011a9ee0d3&source_detail=WPH15%2F01+October+2020) | | **Q4** MCQ | [U5 Thermodynamics](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/thermodynamics/) | 1 | 0.45 Medium | 0.20 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=4fea49c1-57e1-4b19-b433-814e276ae703&source_detail=WPH15%2F01+October+2020) | | **Q5** MCQ | [U5 Oscillations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/oscillations/) | 1 | 0.45 Medium | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=37dd8a1f-333a-4d03-b2c6-e19afa9888a9&source_detail=WPH15%2F01+October+2020) | | **Q6** MCQ | [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) | 1 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=447322df-f007-4479-a1c6-13a63b1b0cb5&source_detail=WPH15%2F01+October+2020) | | **Q7** MCQ | [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) | 1 | 0.45 Medium | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=ca43b410-d598-46f4-8261-7c23d3173080&source_detail=WPH15%2F01+October+2020) | | **Q8** MCQ | [U5 Thermodynamics](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/thermodynamics/) | 1 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=484b7112-c1ab-41a8-b9d2-f3e0649de775&source_detail=WPH15%2F01+October+2020) | | **Q9** MCQ | [U5 Oscillations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/oscillations/) | 1 | 0.45 Medium | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=78ceb40f-eef1-4e46-82a9-f41ed9f81676&source_detail=WPH15%2F01+October+2020) | | **Q10** MCQ | [U5 Oscillations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/oscillations/) | 1 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=1aacae39-9bfa-4904-bca5-b5edea53537e&source_detail=WPH15%2F01+October+2020) | | **Q11** FRQ | [U5 Astrophysics and Cosmology](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) | 2 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=5c841a7d-b124-4763-bc4f-db95928708db&source_detail=WPH15%2F01+October+2020) | | **Q12** FRQ | [U5 Astrophysics and Cosmology](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) | 5 | 0.35 Medium | 0.20 Low | 0.35 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=7c20b143-ed58-4b30-925b-687201386176&source_detail=WPH15%2F01+October+2020) | | **Q13** FRQ | [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) | 4 | 0.45 Medium | 0.20 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=8e3a3e75-d785-40aa-91a2-65feb00222a6&source_detail=WPH15%2F01+October+2020) | | **Q14** FRQ | [U5 Astrophysics and Cosmology](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) | 4 | 0.33 Medium | 0.20 Low | 0.33 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=a4a2a0ce-1fe0-43ed-9a0f-0bb3ca567906&source_detail=WPH15%2F01+October+2020) | | **Q15** FRQ | [U5 Astrophysics and Cosmology](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) | 7 | 0.41 Medium | 0.31 Low | 0.41 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=fa540f35-7934-491b-a26e-2c75ae653239&source_detail=WPH15%2F01+October+2020) | | **Q16** FRQ | [U5 Astrophysics and Cosmology](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) | 8 | 0.36 Medium | 0.36 Medium | 0.29 Low | [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) | | **Q17** FRQ | [U5 Thermodynamics](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/thermodynamics/) | 12 | 0.57 Medium | 0.33 Medium | 0.60 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=e20222d0-c030-4b19-97c5-2b3ae0fbd0d3&source_detail=WPH15%2F01+October+2020) | | **Q18** FRQ | [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) | 12 | 0.37 Medium | 0.37 Medium | 0.30 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=1b97e93c-25ae-465d-8e8b-5e761eb32621&source_detail=WPH15%2F01+October+2020) | | **Q19** FRQ | [U5 Oscillations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/oscillations/) | 14 | 0.42 Medium | 0.33 Medium | 0.36 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=8ae7a889-a90b-4d31-b0a0-876265323efc&source_detail=WPH15%2F01+October+2020) | | **Q20** FRQ | [U5 Oscillations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/oscillations/) | 12 | 0.56 Medium | 0.30 Low | 0.30 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a3931f7-4a72-41eb-af5a-0d315b2148a6&question_id=d527eb86-b5de-4f7d-959b-2bd4e151afc8&source_detail=WPH15%2F01+October+2020) | ## Topics in this paper - [U5 Nuclear Decay](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/nuclear-decay/) - [U5 Thermodynamics](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/thermodynamics/) - [U5 Oscillations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/oscillations/) - [U5 Astrophysics and Cosmology](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-5-wph15/astrophysics-and-cosmology/) ## Related papers - [WPH15/01](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2021-october-wph15-01/) — October 2021 — 21 questions · 90 marks — Pro - [WPH15/01](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2021-june-wph15-01/) — June 2021 — 19 questions · 90 marks — Pro - [WPH15/01](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2021-january-wph15-01/) — January 2021 — 20 questions · 90 marks — Pro - [WPH15/01](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-october-wph15-01/) — October 2022 — 20 questions · 90 marks — Pro - [WPH15/01](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-june-wph15-01/) — June 2022 — 20 questions · 90 marks — Pro - [WPH15/01](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2022-january-wph15-01/) — January 2022 — 20 questions · 90 marks — Pro ## Paper FAQ **How are the difficulty and complexity measures calculated?** Each part is weighted by its official marks. Difficulty uses Easy 0.20, Medium 0.45 and Hard 0.75; algebraic complexity and text density and modelling use Low 0.20, Medium 0.45 and High 0.75. A Hard part worth 4 or more marks is down-weighted to marks^0.75, so the accessible starter steps inside a long structured question do not inflate the difficulty result. This paper's Difficulty Measure is 0.42 from 39 parts. **What does the Difficulty Deviation show?** It is the mark-weighted standard deviation of the part difficulty values around the paper mean. A value of 0 would mean every tagged part has the same difficulty; this paper's deviation is 0.18, so its parts are more mixed than a single-level paper. **Is the Difficulty Ratio based on question counts or marks?** It is based on official marks, not question counts. This paper's shares are 28.9% Easy, 52.2% Medium and 18.9% Hard; the three shares sum to 100% before rounding. **Are these official difficulty ratings?** No. They are derived from the platform's part-level difficulty and static-question-profile tags. They are not exam-board grade boundaries and are not calculated from candidate outcomes. Use them to compare the demand profile of papers, not to predict a grade. **Why does each question row show its own measures?** Each row recalculates the same mark-weighted formula from that question's parts. A single-part MCQ therefore shows the tag value directly, while a multi-part structured question blends the tags of its parts using the same Hard-part decay as the paper profile. --- Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-5-wph15/2020-october-wph15-01/