# 9702/42 March 2020

> 9702/42 March 2020: 12 questions, 100 marks. Difficulty 0.35, deviation 0.14, algebraic 0.25, text density 0.36. CIE IAL Physics 9702 P4.

- Canonical HTML: https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-march-9702-42/
- Markdown mirror: https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-march-9702-42/index.md

---

CIE IAL · Physics · 2020 March

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=9fa086c2-dadd-45f3-a1e1-08c8764c19af)
- [All 9702 P4 papers](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/)

Core finding

**9702/42 March 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 0.14 and a mark split of 45.0% Easy, 52.0% Medium and 3.0% Hard. Algebraic complexity averages 0.25; text density and modelling average 0.36. All five measures use 50 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 50 parts carrying 100 part marks. Difficulty tags cover 50 parts, algebraic tags 50 and text-density tags 50. Tags are internal metadata, not official exam-board ratings.

- **Difficulty Measure**: 0.35 — 0.20–0.75 · nearer Medium
- **Difficulty Deviation**: 0.14 — 0 = uniform; higher = more mixed
- **Difficulty Ratio**: 45.0 / 52.0 / 3.0 — % Easy / Medium / Hard
- **Algebraic Complexity Measure**: 0.25 — 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** | 0.35 | Σ(d_i × w_i) / Σw_i, with d = 0.20 / 0.45 / 0.75 |
| **Difficulty Deviation** | 0.14 | √(Σw_i(d_i − μ)^2 / Σw_i) |
| **Difficulty Ratio** | 45.0% Easy / 52.0% Medium / 3.0% Hard | marks in band / all tagged marks |
| **Algebraic Complexity Measure** | 0.25 | 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** FRQ | [8.4 Gravitational potential](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-potential/) | 10 | 0.35 Medium | 0.35 Medium | 0.40 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=ed23a8b4-7cdb-43e8-a91c-4b1580827765&source_detail=9702%2F42+March+2020) |
| **Q2** FRQ | [1.3 The Avogadro constant](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 10 | 0.35 Medium | 0.28 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=18b47c7d-e8d5-408d-b68c-751d399d76be&source_detail=9702%2F42+March+2020) |
| **Q3** FRQ | [13.1 Simple harmonic oscillations](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/simple-harmonic-oscillations/) | 10 | 0.35 Medium | 0.20 Low | 0.28 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=d22b7b53-6149-4804-9dac-d87a000b1739&source_detail=9702%2F42+March+2020) |
| **Q4** FRQ | [14.6 Production and use of ultrasound in diagnosis](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 8 | 0.36 Medium | 0.20 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=d8487a49-402e-436a-abcd-308691934650&source_detail=9702%2F42+March+2020) |
| **Q5** FRQ | [16.3 Digital communication](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 7 | 0.38 Medium | 0.31 Low | 0.38 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=de03fbc2-d53f-489e-bcd7-9a9b685cc799&source_detail=9702%2F42+March+2020) |
| **Q6** FRQ | [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/) | 8 | 0.41 Medium | 0.29 Low | 0.29 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=e496bf12-d9e1-4c1f-9033-55f6b1b29e2b&source_detail=9702%2F42+March+2020) |
| **Q7** FRQ | [19.4 Sensing devices](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 7 | 0.38 Medium | 0.20 Low | 0.38 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=fa61135b-de6b-4632-b827-11fe1bd1e85f&source_detail=9702%2F42+March+2020) |
| **Q8** FRQ | [22.1 Concept of magnetic field](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 8 | 0.36 Medium | 0.20 Low | 0.36 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=efde5afb-418f-4aff-bc9e-f3b73f02f4dd&source_detail=9702%2F42+March+2020) |
| **Q9** FRQ | [24.1 Characteristics of alternating currents](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/characteristics-of-alternating-currents/) | 8 | 0.33 Medium | 0.20 Low | 0.33 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=c7b9bf24-e3e7-48dc-8ccd-fcf906bbe474&source_detail=9702%2F42+March+2020) |
| **Q10** FRQ | [25.2 Photoelectric emission of electrons](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 7 | 0.27 Easy | 0.20 Low | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=3d113e34-3dd2-4068-8b59-67b4649a9458&source_detail=9702%2F42+March+2020) |
| **Q11** 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/) | 9 | 0.34 Medium | 0.26 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=a501d83c-1a5b-4505-a8d1-66f1d5cacf4f&source_detail=9702%2F42+March+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/) | 8 | 0.29 Easy | 0.29 Low | 0.29 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9fa086c2-dadd-45f3-a1e1-08c8764c19af&question_id=e8e3e727-02b9-4a82-ab70-c8011844da6b&source_detail=9702%2F42+March+2020) |

## Topics in this paper

- [8.4 Gravitational potential](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-potential/)
- [7.2 Centripetal acceleration and centripetal force](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [8.2 Gravitational force between point masses](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-force-between-point-masses/)
- [8.3 Gravitational field of a point mass](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-field-of-a-point-mass/)
- [1.3 The Avogadro constant](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/)
- [12.1 Specific heat capacity and specific latent heat](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/specific-heat-capacity-and-specific-latent-heat/)
- [10.2 Kinetic theory of gases](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/kinetic-theory-of-gases/)
- [10.3 Kinetic energy of a molecule](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [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/)
- [23.1 Laws of electromagnetic induction](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)

## Related papers

- [9702/41](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-october-november-9702-41/) — October/November 2020 — 12 questions · 100 marks — Free
- [9702/42](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-october-november-9702-42/) — October/November 2020 — 12 questions · 100 marks — Free
- [9702/43](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-october-november-9702-43/) — October/November 2020 — 12 questions · 100 marks — Free
- [9702/41](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-may-june-9702-41/) — May/June 2020 — 12 questions · 100 marks — Free
- [9702/42](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-may-june-9702-42/) — May/June 2020 — 12 questions · 100 marks — Free
- [9702/43](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/2020-may-june-9702-43/) — May/June 2020 — 12 questions · 100 marks — Free

## 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 50 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 0.14, 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 45.0% Easy, 52.0% Medium and 3.0% 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.

---

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