# 9702 P4 Stellar radii Topic Questions

> CIE IAL 9702 P4: every Stellar radii topic question from 9 papers (2025–2026), grouped by syllabus point. 16 questions, 30 marks, with direct links into the…

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CIE IAL · Physics · 9702 P4 · A Level

Every 9702 P4 Stellar radii topic question from the 2025–2027 syllabus, drawn from 9 papers (2025–2026) and grouped by syllabus point. Each row opens a page listing the exact question numbers, marks and a direct link into the paper. These are questions by topic, not full papers, so you can revise one topic at a time.

- 9702 P4
- 3 subtopics
- 16 topic questions
- 9 papers
- 30 tagged marks
- [Back to Stellar radii](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/)
- [All paper codes](https://www.examsci.com/topics/)

Core finding

**1 recall and use Wien’s displacement law … to estimate the peak… is the most frequently assessed subtopic in Stellar radii, with 11 topic questions and 21 marks across 7 papers.** 2 use the Stefan–Boltzmann law … follows with 7 topic questions and 15 marks. The topic contains 3 subtopics, 16 topic questions and 30 marks in total. Rows count only the parts tagged to that subtopic, keep the same colour in both charts and repeat paper count, tagged marks and year range in the native table.

## Topic question count and mark distribution

Subtopics are on the vertical axis and sorted from highest to lowest. Only the parts whose knowledge graph matches a subtopic are counted for it, and percentages are each row's share of the tagged total in that chart. A part tagged to several subtopics is counted in each bar, so the bars are not a partition of the topic total.

### Questions by subtopic

question items

- [1 recall and use Wien’s displacement law $\lambda_{max} \propto 1 / T$ to estimate the peak surface temperature of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/1-recall-and-use-wien-s-displacement-law-lambda-max-propto-1-t-to-estimate-the-peak/) (7 papers) — 11 · 55.0%
- [2 use the Stefan–Boltzmann law $L = 4\pi\sigma r^2 T^4$](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/2-use-the-stefan-boltzmann-law-l-4-pi-sigma-r-2-t-4/) (7 papers) — 7 · 35.0%
- [3 use Wien’s displacement law and the Stefan–Boltzmann law to estimate the radius of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/3-use-wien-s-displacement-law-and-the-stefan-boltzmann-law-to-estimate-the-radius-of/) (2 papers) — 2 · 10.0%

### Marks by subtopic

marks

- [1 recall and use Wien’s displacement law $\lambda_{max} \propto 1 / T$ to estimate the peak surface temperature of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/1-recall-and-use-wien-s-displacement-law-lambda-max-propto-1-t-to-estimate-the-peak/) (7 papers) — 21 · 52.5%
- [2 use the Stefan–Boltzmann law $L = 4\pi\sigma r^2 T^4$](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/2-use-the-stefan-boltzmann-law-l-4-pi-sigma-r-2-t-4/) (7 papers) — 15 · 37.5%
- [3 use Wien’s displacement law and the Stefan–Boltzmann law to estimate the radius of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/3-use-wien-s-displacement-law-and-the-stefan-boltzmann-law-to-estimate-the-radius-of/) (2 papers) — 4 · 10.0%

## Subtopic comparison matrix

Curriculum order is by syllabus number, then alphabetically. Every row links to the matching past-paper question list.

| Subtopic | Topic questions | Papers | Marks | Years | |
| --- | --- | --- | --- | --- | --- |
| **[1 recall and use Wien’s displacement law $\lambda_{max} \propto 1 / T$ to estimate the peak surface temperature of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/1-recall-and-use-wien-s-displacement-law-lambda-max-propto-1-t-to-estimate-the-peak/)** | 11 | 7 | 21 | 2025–2026 | [Open topic questions](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/1-recall-and-use-wien-s-displacement-law-lambda-max-propto-1-t-to-estimate-the-peak/) |
| **[2 use the Stefan–Boltzmann law $L = 4\pi\sigma r^2 T^4$](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/2-use-the-stefan-boltzmann-law-l-4-pi-sigma-r-2-t-4/)** | 7 | 7 | 15 | 2025–2026 | [Open topic questions](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/2-use-the-stefan-boltzmann-law-l-4-pi-sigma-r-2-t-4/) |
| **[3 use Wien’s displacement law and the Stefan–Boltzmann law to estimate the radius of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/3-use-wien-s-displacement-law-and-the-stefan-boltzmann-law-to-estimate-the-radius-of/)** | 2 | 2 | 4 | 2025–2026 | [Open topic questions](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/3-use-wien-s-displacement-law-and-the-stefan-boltzmann-law-to-estimate-the-radius-of/) |

## Browse every topic question

- [1 recall and use Wien’s displacement law $\lambda_{max} \propto 1 / T$ to estimate the peak surface temperature of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/1-recall-and-use-wien-s-displacement-law-lambda-max-propto-1-t-to-estimate-the-peak/) — 11 question items · 7 papers — 21 marks · 2025–2026
- [2 use the Stefan–Boltzmann law $L = 4\pi\sigma r^2 T^4$](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/2-use-the-stefan-boltzmann-law-l-4-pi-sigma-r-2-t-4/) — 7 question items · 7 papers — 15 marks · 2025–2026
- [3 use Wien’s displacement law and the Stefan–Boltzmann law to estimate the radius of a star](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/stellar-radii/3-use-wien-s-displacement-law-and-the-stefan-boltzmann-law-to-estimate-the-radius-of/) — 2 question items · 2 papers — 4 marks · 2025–2026

## Other topics in 9702 P4

- [Capacitors and capacitance 17 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/capacitors-and-capacitance/)
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- [Concept of a magnetic field 3 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/concept-of-a-magnetic-field/)
- [Damped and forced oscillations, resonance 7 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/damped-and-forced-oscillations-resonance/)
- [Discharging a capacitor 16 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/discharging-a-capacitor/)
- [Electric field of a point charge 8 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/electric-field-of-a-point-charge/)
- [Electric fields and field lines 7 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/electric-fields-and-field-lines/)
- [Electric force between point charges 12 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/electric-force-between-point-charges/)
- [Electric potential 26 question items](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/electric-potential/)

## Topic question rules and edge cases

**How many subtopics does Stellar radii contain?**

This page lists 3 subtopics tagged to the current syllabus. They are ordered by syllabus number, then alphabetically, and each row opens a page of matching past-paper questions.

**How are the subtopic question and mark totals calculated?**

A multiple-choice question contributes one item and its marks to every subtopic it is tagged with. A structured question contributes one item per tagged part, and that part’s marks; untagged parts of the same question are not counted here. A part tagged to several subtopics therefore appears under each of them.

**Why do some subtopics have no numbered prefix?**

Practical-skills statements and some syllabus bullets are unnumbered. Numbered statements come first; unnumbered statements and ties are sorted alphabetically.

**Is the LaTeX rendered without JavaScript?**

Yes. Subtopics that contain formulas are converted to static KaTeX HTML during the build, and the KaTeX stylesheet is served from the same site.

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