# 9702/42 October/November 2020

> 9702/42 October/November 2020: 12 questions, 100 marks. Difficulty 0.35, deviation 0.16, algebraic 0.24, text density 0.33. CIE IAL Physics 9702 P4.

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CIE IAL · Physics · 2020 October/November

This Physics 9702 Paper 4 (A Level Structured) paper contains 12 questions worth 100 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.

- CIE IAL
- 9702 P4
- 12 questions
- 100 marks
- Free paper
- [Practise this paper](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8)
- [All 9702 P4 papers](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/)

Core finding

**9702/42 October/November 2020 is a past paper for CIE IAL Physics 9702 Paper 4 (A Level Structured), with 12 questions worth 100 marks.** Its mark-weighted Difficulty Measure is 0.35 on a 0.20–0.75 scale, with a Difficulty Deviation of 0.16 and a mark split of 47.0% Easy, 45.0% Medium and 8.0% Hard. Algebraic complexity averages 0.24; text density and modelling average 0.33. All five measures use 47 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 47 parts carrying 100 part marks. Difficulty tags cover 47 parts, algebraic tags 47 and text-density tags 47. Tags are internal metadata, not official exam-board ratings.

- **Difficulty Measure**: 0.35 — 0.20–0.75 · nearer Medium
- **Difficulty Deviation**: 0.16 — 0 = uniform; higher = more mixed
- **Difficulty Ratio**: 47.0 / 45.0 / 8.0 — % Easy / Medium / Hard
- **Algebraic Complexity Measure**: 0.24 — 0.20–0.75 · nearer Low
- **Text Density and Modelling Measure**: 0.33 — 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** | 0.35 | Σ(d_i × w_i) / Σw_i, with d = 0.20 / 0.45 / 0.75 |
| **Difficulty Deviation** | 0.16 | √(Σw_i(d_i − μ)^2 / Σw_i) |
| **Difficulty Ratio** | 47.0% Easy / 45.0% Medium / 8.0% Hard | marks in band / all tagged marks |
| **Algebraic Complexity Measure** | 0.24 | Σ(c_i × marks_i) / Σmarks_i, with c = 0.20 / 0.45 / 0.75 |
| **Text Density and Modelling Measure** | 0.33 | 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** FRQ | [8.4 Gravitational potential](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-potential/) | 9 | 0.39 Medium | 0.37 Medium | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=648f27be-5a48-4b48-8045-c18030bbac13&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q2** FRQ | [12.2 Internal energy and the first law of thermodynamics](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 10 | 0.28 Easy | 0.20 Low | 0.33 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=f57ef079-a1f2-47fe-9072-01fbe4cc1169&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q3** FRQ | [13.1 Simple harmonic oscillations](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/simple-harmonic-oscillations/) | 10 | 0.38 Medium | 0.33 Medium | 0.38 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=8b77d012-e71d-45f6-9215-81bb1089aa34&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q4** FRQ | [16.3 Digital communication](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 9 | 0.37 Medium | 0.20 Low | 0.39 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=a8521dee-0a07-4e24-94d9-b37eb88995a6&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q5** FRQ | [8.1 Gravitational field](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-field/) | 11 | 0.31 Easy | 0.20 Low | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=409f5314-af13-4b6e-b24e-e7adeaefaced&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q6** FRQ | [18.1 Capacitors and capacitance](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/capacitors-and-capacitance/) | 7 | 0.20 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=e719a2d8-dd5a-43be-9446-125e49bee691&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q7** FRQ | [25.6 Production and use of X-rays](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/production-and-use-of-x-rays/) | 6 | 0.45 Medium | 0.20 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=68708079-588b-46bb-9f77-a4abd3577143&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q8** FRQ | [21.1 The ideal operational amplifier](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 6 | 0.20 Easy | 0.20 Low | 0.28 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=56647a9a-0b44-4bd8-9617-56982b6ff4b5&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q9** FRQ | [23.1 Laws of electromagnetic induction](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 8 | 0.50 Medium | 0.20 Low | 0.39 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=8c94278b-51f3-4e5b-bbd2-8a3b22843b2c&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q10** FRQ | [22.4 Magnetic fields due to currents](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/magnetic-fields-due-to-currents/) | 7 | 0.27 Easy | 0.20 Low | 0.27 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=9d2b98c2-b930-4963-954e-23f767d79af5&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q11** FRQ | [25.2 Photoelectric emission of electrons](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 10 | 0.49 Medium | 0.30 Low | 0.35 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=cfa3b568-87fc-40d7-8ba5-5509fc5c2cbb&source_detail=9702%2F42+October%2FNovember+2020) |
| **Q12** FRQ | [26.3 Mass defect and nuclear binding energy](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/mass-defect-and-nuclear-binding-energy/) | 7 | 0.31 Easy | 0.20 Low | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=80f5f181-8683-4cf9-b26c-7e9c00f6aab8&question_id=bb0a5a57-c04c-43a6-8d55-5dd41968dacf&source_detail=9702%2F42+October%2FNovember+2020) |

## Topics in this paper

- [8.4 Gravitational potential](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-potential/)
- [8.2 Gravitational force between point masses](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-force-between-point-masses/)
- [12.2 Internal energy and the first law of thermodynamics](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [10.1 Equation of state](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/equation-of-state/)
- [13.1 Simple harmonic oscillations](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/simple-harmonic-oscillations/)
- [13.2 Energy in simple harmonic motion](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/energy-in-simple-harmonic-motion/)
- [16.3 Digital communication](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [8.1 Gravitational field](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-field/)
- [17.5 Electric potential](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/electric-potential/)
- [17.4 Electric field of a point charge](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/electric-field-of-a-point-charge/)
- [18.1 Capacitors and capacitance](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/capacitors-and-capacitance/)
- [18.2 Energy stored in a capacitor](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/energy-stored-in-a-capacitor/)

## Related papers

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## 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 0.35 from 47 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 0.16, 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 47.0% Easy, 45.0% Medium and 8.0% 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.

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Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-october-november-9702-42/