# Topic Questions: 80 understand how changes of resistance with illumination may be modelled in terms of the number of conduction electrons and understand how to apply this model to LDRs. — WPH12 Electric Circuits

> 8 WPH12 Electric Circuits topic questions (22 marks) on 80 understand how changes of resistance with… — 8 papers, 2019–2026. Open the exact question in the…

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Edexcel IAL · Physics · WPH12 · Electric Circuits

8 WPH12 Electric Circuits topic questions are tagged to this syllabus point across 8 papers (2019–2026). Only the parts whose knowledge graph matches this syllabus statement are counted, and the table shows which parts of each question are involved.

- 8 topic questions
- 8 papers
- 22 tagged marks
- 3.0% of topic questions
- 3.5% of topic marks
- 2019–2026
- Syllabus 2018–current
- [All WPH12 Electric Circuits topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/)
- [All paper codes](https://www.examsci.com/topics/)

Core finding

**This Electric Circuits syllabus point appears in 8 WPH12 papers across 2019–2026, contributing 8 topic questions and 22 marks.** The most recent appearance is WPH12/01 January 2026. That equals 3.0% of the 268 topic questions and 3.5% of the 634 marks tagged to Electric Circuits. 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 |
| --- | --- | --- | --- | --- | --- | --- |
| [**WPH12/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2026-january-wph12-01/#q-4) | **Q4** LDR Circuits - Edexcel IAL Physics Jan 2026 Q4 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=f217f3ed-8314-4b5a-a273-52fcc7614327&question_id=098d8993-ebfd-4780-ab70-25c16ff5610d&source_detail=WPH12%2F01+January+2026) |
| [**WPH12/01** January 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2025-january-wph12-01/#q-16) | **Q16** LDR Potential Divider and Voltmeter Reading - Edexcel IAL Physics Jan 2025 Q16 | FRQ | 1 of 2 parts ((b)) | 6 of 7 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e619207f-bc85-4481-9d5b-1fbdc31ada66&question_id=65feaba6-3eb3-4548-ac60-594fc227053b&source_detail=WPH12%2F01+January+2025) |
| [**WPH12/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2024-january-wph12-01/#q-2) | **Q2** LDR Characteristics - Edexcel IAL Physics Jan 2024 Q2 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=030444a8-988a-46b6-9902-c76464e7c5f1&question_id=73653f51-5b6d-4a37-a602-873446eb3594&source_detail=WPH12%2F01+January+2024) |
| [**WPH12/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2023-june-wph12-01/#q-14) | **Q14** LDR Potential Divider Circuit - Edexcel IAL Physics May 2023 Q14 | FRQ | 1 part | 6 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3a8e11e5-0ef0-468b-b140-32d6d8e746b5&question_id=5ecd4f2e-96b8-4d87-ada4-062490adc9df&source_detail=WPH12%2F01+June+2023) |
| [**WPH12/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2022-june-wph12-01/#q-9) | **Q9** Conduction Electrons in LDR - Edexcel IAL Physics June 2022 Q9 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3069ad40-1aa5-4af5-a2d4-5c7bfc121c7d&question_id=847a81ab-b259-4c53-b632-ba4cf7075541&source_detail=WPH12%2F01+June+2022) |
| [**WPH12/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2022-january-wph12-01/#q-10) | **Q10** LDR and Potential Divider Circuit Behavior - Edexcel IAL Physics Jan 2022 Q10 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=272cf6d5-ace3-46e9-81c3-821d84b7c606&question_id=9e72714c-5c77-43bc-953c-96f0174a9102&source_detail=WPH12%2F01+January+2022) |
| [**WPH12/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2021-january-wph12-01/#q-13) | **Q13** LDR Resistance Investigation - Edexcel IAL Physics Jan 2021 Q13 | FRQ | 1 of 2 parts ((b)) | 2 of 4 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=0685a005-c20b-4099-9db0-869cf6f6e4cf&question_id=0b41e96e-4c02-4efc-8e42-4967c6d3b563&source_detail=WPH12%2F01+January+2021) |
| [**WPH12/01** June 2019 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-2-wph12/2019-june-wph12-01/#q-15) | **Q15** Resistor Combinations and Potential Divider Circuits - Edexcel IAL Physics May 2019 Q15 | FRQ | 1 of 4 parts ((c)(ii)) | 4 of 13 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ac1ff5b2-f21b-4af1-906c-a87572cb18c1&question_id=e69942a3-8d09-48ab-85fb-452d45ceb8b0&source_detail=WPH12%2F01+June+2019) |

## Related topic questions in Electric Circuits

- [64 understand that electric current is the rate of flow of charged particles and be able to use the equation $I=\frac{\Delta Q}{\Delta t}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/64-understand-that-electric-current-is-the-rate-of-flow-of-charged-particles-and-be/) — 17 question items · 15 papers — 39 marks · 2019–2026
- [65 understand how to use the equation $V=\frac{W}{Q}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/65-understand-how-to-use-the-equation-v-frac-w-q/) — 17 question items · 13 papers — 31 marks · 2019–2026
- [66 understand that resistance is defined by $R=\frac{V}{I}$ and that Ohm's law is a special case when $I\propto V$ for constant temperature](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/66-understand-that-resistance-is-defined-by-r-frac-v-i-and-that-ohm-s-law-is-a/) — 20 question items · 14 papers — 55 marks · 2020–2026
- [67a understand how the distribution of current in a circuit is a consequence of charge conservation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/67a-understand-how-the-distribution-of-current-in-a-circuit-is-a-consequence-of/) — 12 question items · 10 papers — 32 marks · 2020–2025
- [67b understand how the distribution of potential differences in a circuit is a consequence of energy conservation](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/67b-understand-how-the-distribution-of-potential-differences-in-a-circuit-is-a/) — 13 question items · 10 papers — 34 marks · 2020–2025
- [68 be able to derive the equations for combining resistances in series and parallel using the principles of charge and energy conservation, and be able to use these equations](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/68-be-able-to-derive-the-equations-for-combining-resistances-in-series-and-parallel/) — 39 question items · 20 papers — 118 marks · 2019–2026

## Topic question rules and edge cases

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

8 question stems cover this subtopic across 8 papers, but only 8 tagged parts and 22 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 2019–2026. 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.

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Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-2-wph12/electric-circuits/80-understand-how-changes-of-resistance-with-illumination-may-be-modelled-in-terms-of/