# Topic Questions: 115 be able to derive and use the equation $r=\frac{p}{BQ}$ for a charged particle in a magnetic field — WPH14 Nuclear and Particle Physics

> 31 WPH14 Nuclear and Particle Physics topic questions (91 marks) on 115 be able to derive and use the equation … for… — 19 papers, 2020–2026. Open the exact…

- Canonical HTML: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/115-be-able-to-derive-and-use-the-equation-r-frac-p-bq-for-a-charged-particle-in-a/
- Markdown mirror: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/115-be-able-to-derive-and-use-the-equation-r-frac-p-bq-for-a-charged-particle-in-a/index.md

---

Edexcel IAL · Physics · WPH14 · Nuclear and Particle Physics

31 WPH14 Nuclear and Particle Physics topic questions are tagged to this syllabus point across 19 papers (2020–2026). 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
- 11.2% of topic questions
- 13.9% of topic marks
- 2020–2026
- Syllabus 2018–current
- [All WPH14 Nuclear and Particle Physics topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/)
- [All paper codes](https://www.examsci.com/topics/)

Core finding

**This Nuclear and Particle Physics syllabus point appears in 19 WPH14 papers across 2020–2026, contributing 31 topic questions and 91 marks.** The most recent appearance is WPH14/01 January 2026. That equals 11.2% of the 278 topic questions and 13.9% of the 656 marks tagged to Nuclear and Particle Physics. 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 |
| --- | --- | --- | --- | --- | --- | --- |
| [**WPH14/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2026-january-wph14-01/#q-9) | **Q9** Path Radius of Charged Particles in Magnetic Field - Edexcel IAL Physics Unit 4 Jan 2026 Q9 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=07537f0c-01cf-4760-bd10-3eed77f7d0a6&question_id=0a648042-5394-450a-8c58-24ab1bb9dc25&source_detail=WPH14%2F01+January+2026) |
| [**WPH14/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2026-january-wph14-01/#q-16) | **Q16** Pair Production of Electron-Positron Pair - Edexcel IAL Physics Unit 4 Jan 2026 Q16 | FRQ | 1 of 3 parts ((c)) | 6 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=07537f0c-01cf-4760-bd10-3eed77f7d0a6&question_id=522e8e7b-0ef4-4fc3-8591-0892cef0f603&source_detail=WPH14%2F01+January+2026) |
| [**WPH14/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2026-january-wph14-02/#q-14) | **Q14** Lambda Particle Decay and Deflection - Edexcel IAL Physics Jan 2026 Q14 | FRQ | 1 of 4 parts ((c)) | 4 of 10 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ee1f4910-5f08-42aa-b80e-e6f9fada0b73&question_id=983850ab-f89f-425b-b1e3-72b9d1ef6afc&source_detail=WPH14%2F02+January+2026) |
| [**WPH14/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2026-january-wph14-02/#q-18) | **Q18** Anderson's Positron Discovery - Edexcel IAL Physics Jan 2026 Q18 | FRQ | 1 of 5 parts ((c)(ii)) | 3 of 16 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ee1f4910-5f08-42aa-b80e-e6f9fada0b73&question_id=2ce99975-82ef-4171-bc65-cc9389aa86e4&source_detail=WPH14%2F02+January+2026) |
| [**WPH14/01** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2025-october-wph14-01/#q-18) | **Q18** Pion Decay in a Bubble Chamber - Edexcel IAL Physics Oct 2025 Q18 | FRQ | 1 of 3 parts ((a)) | 3 of 6 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=c925843a-0326-4cc4-a60c-ebad9960c7c0&question_id=dac915b0-d062-4a1e-a82e-f62d2fe4e180&source_detail=WPH14%2F01+October+2025) |
| [**WPH14/01** June 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2025-june-wph14-01/#q-16) | **Q16** Linac and Cyclotron Acceleration - Edexcel IAL Physics June 2025 Q16 | FRQ | 1 of 3 parts ((b)(ii)) | 3 of 13 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3fa77855-5a47-4e9d-9d77-8e6feeafb348&question_id=f898b431-f8ca-4c04-837d-72029d4a67dd&source_detail=WPH14%2F01+June+2025) |
| [**WPH14/01** January 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2025-january-wph14-01/#q-17) | **Q17** Protons in a Cyclotron - Edexcel IAL Physics Jan 2025 Q17 | FRQ | 1 of 3 parts ((b)) | 3 of 11 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3fa71427-5fa5-4200-87e4-7de25234272d&question_id=65b6adcc-144f-43b0-bfe6-a7405960b79b&source_detail=WPH14%2F01+January+2025) |
| [**WPH14/01** October 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-october-wph14-01/#q-18) | **Q18** Sigma Plus Particle Decay - Edexcel IAL Physics Oct 2024 Q18 | FRQ | 1 of 5 parts ((a)) | 2 of 17 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b5bd6e3e-5afd-4869-ad78-ba1875109b46&question_id=24185110-874d-4bb6-9335-52151d12298e&source_detail=WPH14%2F01+October+2024) |
| [**WPH14/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-june-wph14-01/#q-9) | **Q9** Decreasing Radius of Proton in Magnetic Field - Edexcel IAL Physics Unit 4 June 2024 Q9 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=cd6c5948-4054-4ae4-8638-e8fde551f1f4&question_id=5ccf99c1-2ddb-4717-81a3-ae60edb09419&source_detail=WPH14%2F01+June+2024) |
| [**WPH14/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-june-wph14-01/#q-10) | **Q10** Radius of Alpha Particle in Magnetic Field - Edexcel IAL Physics Unit 4 June 2024 Q10 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=cd6c5948-4054-4ae4-8638-e8fde551f1f4&question_id=5de95c6c-d052-440d-9611-e4d5bee83910&source_detail=WPH14%2F01+June+2024) |
| [**WPH14/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-january-wph14-01/#q-19) | **Q19** Oxygen Atomic Transitions and Circular Electron Radiation - Edexcel IAL Physics Jan 2024 Q19 | FRQ | 1 of 2 parts ((b)) | 5 of 8 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=7f671b10-3bb0-47d7-9ab5-58b3498dd1dd&question_id=d8c1028e-40c0-4075-9aa3-124b16944d47&source_detail=WPH14%2F01+January+2024) |
| [**WPH14/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-january-wph14-01/#q-22) | **Q22** Kaon Structure and Cyclotron Principles - Edexcel IAL Physics Jan 2024 Q22 | FRQ | 1 of 4 parts ((b)(ii)) | 4 of 13 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=7f671b10-3bb0-47d7-9ab5-58b3498dd1dd&question_id=2abf38f3-c90b-4aaf-a79c-b73cc41e6090&source_detail=WPH14%2F01+January+2024) |
| [**WPH14/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-october-wph14-01/#q-7) | **Q7** Charged Particles in Magnetic Field - Edexcel IAL Physics Oct 2023 Q7 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=63cf6d9e-c5b2-42b1-b898-7773fe6081a7&question_id=6cdd62d8-3c3e-4900-a623-0d62c9209dab&source_detail=WPH14%2F01+October+2023) |
| [**WPH14/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-october-wph14-01/#q-22) | **Q22** Specific Charge of Electron - Edexcel IAL Physics Oct 2023 Q22 | FRQ | 1 of 4 parts ((b)(iii)) | 4 of 15 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=63cf6d9e-c5b2-42b1-b898-7773fe6081a7&question_id=27974601-8d5f-4cda-b39d-aa67378b45e2&source_detail=WPH14%2F01+October+2023) |
| [**WPH14/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-june-wph14-01/#q-12) | **Q12** Circular Path in a Magnetic Field - Edexcel IAL Physics June 2023 Q12 | FRQ | 2 parts ((a), (b)) | 6 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2055a28e-816f-4ab5-8253-c37cfd7dd7b9&question_id=653920ff-ca30-484e-9c49-96ce9a8afff5&source_detail=WPH14%2F01+June+2023) |
| [**WPH14/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-january-wph14-01/#q-4) | **Q4** Charged Particle Track in Magnetic Field - Edexcel IAL Physics Jan 2023 Q4 | MCQ | MCQ · 1 part | 1 | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=495cc00c-1d7f-4297-981d-c1c626ca134d&question_id=798c9f5d-1bed-456f-b334-9c9d37d58a24&source_detail=WPH14%2F01+January+2023) |
| [**WPH14/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-january-wph14-01/#q-17) | **Q17** Thomson's Electron Experiment & Wave-Particle Duality - Edexcel IAL Physics Jan 2023 Q17 | FRQ | 1 of 4 parts ((a)(iii)) | 3 of 11 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=495cc00c-1d7f-4297-981d-c1c626ca134d&question_id=2355d7ce-39d8-4109-8000-6b560bbf3809&source_detail=WPH14%2F01+January+2023) |
| [**WPH14/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2022-october-wph14-01/#q-18) | **Q18** Mass Spectrometry and Particle Paths - Edexcel IAL Physics Oct 2022 Q18 | FRQ | 1 of 5 parts ((c)) | 3 of 14 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9be141d5-8b06-4cb6-8fa6-68d1cc9a6174&question_id=642b942e-81c0-42f5-9069-62de94fb2617&source_detail=WPH14%2F01+October+2022) |
| [**WPH14/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2022-june-wph14-01/#q-8) | **Q8** Cyclotron Spiral Path - Edexcel IAL Physics June 2022 Q8 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=6042feb3-c856-448e-8691-d6933b5190bc&question_id=c1d098e7-b4a3-4392-9002-1d6ef8f1de87&source_detail=WPH14%2F01+June+2022) |
| [**WPH14/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2022-june-wph14-01/#q-14) | **Q14** Particle Paths and Properties in Detector - Edexcel IAL Physics June 2022 Q14 | FRQ | 1 of 4 parts ((a)) | 4 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=6042feb3-c856-448e-8691-d6933b5190bc&question_id=afdf8eb2-8904-4e71-b3d7-21d2ba665000&source_detail=WPH14%2F01+June+2022) |
| [**WPH14/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2022-january-wph14-01/#q-17) | **Q17** Muon Classification, Decay and Storage Ring - Edexcel IAL Physics Jan 2022 Q17 | FRQ | 1 of 6 parts ((d)(ii)) | 3 of 14 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=49fe32a1-ed2d-43cb-8e5c-01ad7a065d74&question_id=ee6731cf-78c6-45da-a525-24ee1ba25e01&source_detail=WPH14%2F01+January+2022) |
| [**WPH14/01** October 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2021-october-wph14-01/#q-18) | **Q18** Particle Tracks and Conservation of Momentum - Edexcel IAL Physics Oct 2021 Q18 | FRQ | 2 of 6 parts ((b), (d)) | 6 of 15 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=8cbfca05-d9d4-4992-a2fe-4a148f95c213&question_id=b4d8ef58-706c-4917-b9a3-11c6f9bc0bba&source_detail=WPH14%2F01+October+2021) |
| [**WPH14/01** June 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2021-june-wph14-01/#q-18) | **Q18** Cloud Chamber Positron Track - June 2021 Q18 | FRQ | 2 of 5 parts ((b), (c)(ii)) | 6 of 16 on the paper | Hard | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b192ea77-92eb-44fc-91ce-d3a09157fcbf&question_id=d2f522d0-cfa4-4861-b51e-6c73748c3edb&source_detail=WPH14%2F01+June+2021) |
| [**WPH14/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2021-january-wph14-01/#q-6) | **Q6** Magnetic Field Path Trajectory - Edexcel IAL Physics Jan 2021 Q6 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ad4d3bdd-35e1-4b4e-8408-0afd068c0d8f&question_id=144442ff-98bc-49bb-9913-b3a7a3bbc8a7&source_detail=WPH14%2F01+January+2021) |
| [**WPH14/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2021-january-wph14-01/#q-15) | **Q15** Cyclotron Particle Accelerator Principles - Edexcel IAL Physics Jan 2021 Q15 | FRQ | 1 of 2 parts ((b)) | 4 of 10 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ad4d3bdd-35e1-4b4e-8408-0afd068c0d8f&question_id=fc75ce46-e151-462f-a8bd-e20c1ad6417a&source_detail=WPH14%2F01+January+2021) |
| [**WPH14/01** October 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2020-october-wph14-01/#q-18) | **Q18** Filament Electron Gun and Linac - Edexcel IAL Physics June 2020 Q18 | FRQ | 1 of 5 parts ((d)) | 4 of 14 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=fd185779-00c6-4239-82cf-edc1f6fde6bd&question_id=08c7908c-e5ec-43cf-b229-4fb2964fccda&source_detail=WPH14%2F01+October+2020) |
| [**WPH14/01** January 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2020-january-wph14-01/#q-19) | **Q19** Cyclotron Kinematics and High Energy Protons - Edexcel IAL Physics Jan 2020 Q19 | FRQ | 2 of 4 parts ((a)(i), (b)) | 8 of 15 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=5ef0bb69-523b-4ef4-b94b-964485f16e14&question_id=cf4efda9-b94d-4c22-b7b2-cd0e99a28bcd&source_detail=WPH14%2F01+January+2020) |

## Related topic questions in Nuclear and Particle Physics

- [111 understand what is meant by nucleon number (mass number) and proton number (atomic number)](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/111-understand-what-is-meant-by-nucleon-number-mass-number-and-proton-number-atomic/) — 14 question items · 14 papers — 17 marks · 2020–2026
- [112 understand how large-angle alpha particle scattering gives evidence for a nuclear model of the atom and how our understanding of atomic structure has changed over time](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/112-understand-how-large-angle-alpha-particle-scattering-gives-evidence-for-a-nuclear/) — 29 question items · 20 papers — 76 marks · 2020–2026
- [113 understand that electrons are released in the process of thermionic emission and how they can be accelerated by electric and magnetic fields](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/113-understand-that-electrons-are-released-in-the-process-of-thermionic-emission-and/) — 27 question items · 17 papers — 65 marks · 2020–2026
- [114 understand the role of electric and magnetic fields in particle accelerators (linac and cyclotron) and detectors (general principles of ionisation and deflection only)](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/114-understand-the-role-of-electric-and-magnetic-fields-in-particle-accelerators/) — 37 question items · 19 papers — 100 marks · 2020–2026
- [116 be able to apply conservation of charge, energy and momentum to interactions between particles and interpret particle tracks](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/116-be-able-to-apply-conservation-of-charge-energy-and-momentum-to-interactions/) — 27 question items · 15 papers — 89 marks · 2020–2026
- [117 understand why high energies are required to investigate the structure of nucleons](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/117-understand-why-high-energies-are-required-to-investigate-the-structure-of-nucleons/) — 15 question items · 14 papers — 27 marks · 2020–2026

## Topic question rules and edge cases

**How many topic questions cover this syllabus point?**

27 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 2020–2026. 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-4-wph14/nuclear-and-particle-physics/115-be-able-to-derive-and-use-the-equation-r-frac-p-bq-for-a-charged-particle-in-a/