# 9702/42 March 2019

> 9702/42 March 2019: 12 questions, 100 marks. Difficulty 0.35, deviation 0.14, algebraic 0.25, text density 0.36. CIE IAL Physics 9702 P4.

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CIE IAL · Physics · 2019 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=e80bf1ed-6386-4b1b-9434-7ee65ca27999)
- [All 9702 P4 papers](https://www.examsci.com/past-papers/cie-ial/physics/9702-paper-4/)

Core finding

**9702/42 March 2019 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 42.0% Easy, 55.0% Medium and 3.0% Hard. Algebraic complexity averages 0.25; text density and modelling average 0.36. All five measures use 44 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 44 parts carrying 100 part marks. Difficulty tags cover 44 parts, algebraic tags 44 and text-density tags 44. 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**: 42.0 / 55.0 / 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** | 42.0% Easy / 55.0% 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/) | 12 | 0.35 Medium | 0.24 Low | 0.35 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=6a27bcd2-f5bc-4a97-b32d-efa491b8fd8c&source_detail=9702%2F42+March+2019) |
| **Q2** FRQ | [10.1 Equation of state](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/equation-of-state/) | 10 | 0.33 Medium | 0.28 Low | 0.33 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=b29fe3e9-40cc-421d-9bfc-322c8761ac42&source_detail=9702%2F42+March+2019) |
| **Q3** FRQ | [13.1 Simple harmonic oscillations](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/simple-harmonic-oscillations/) | 10 | 0.33 Medium | 0.28 Low | 0.40 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=7f5fe6d3-a319-44a6-94a7-9030852fb1dc&source_detail=9702%2F42+March+2019) |
| **Q4** FRQ | [8.2 Gravitational force between point masses](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/gravitational-force-between-point-masses/) | 7 | 0.27 Easy | 0.27 Low | 0.34 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=b073e35a-e9d7-41e2-84cb-9f5df6d31e8d&source_detail=9702%2F42+March+2019) |
| **Q5** 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 | 0.42 Medium | 0.29 Low | 0.42 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=cb843873-4c1e-42a2-b252-c88e837c35a4&source_detail=9702%2F42+March+2019) |
| **Q6** FRQ | [18.1 Capacitors and capacitance](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/capacitors-and-capacitance/) | 7 | 0.34 Medium | 0.31 Low | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=cc2dfc94-3d59-4077-b520-552cc23eec65&source_detail=9702%2F42+March+2019) |
| **Q7** FRQ | [21.2 Operational amplifier circuits](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 9 | 0.37 Medium | 0.20 Low | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=f89ebef9-448c-4a43-9baf-fbb18779c3bf&source_detail=9702%2F42+March+2019) |
| **Q8** FRQ | [22.2 Force on a current-carrying conductor](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/force-on-a-current-carrying-conductor/) | 8 | 0.56 Medium | 0.29 Low | 0.45 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=3c5a2282-273d-4b1a-8047-13e1d236065d&source_detail=9702%2F42+March+2019) |
| **Q9** 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/) | 5 | 0.45 Medium | 0.20 Low | 0.75 High | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=613ff8aa-a41c-4f0f-980b-98798a50dd42&source_detail=9702%2F42+March+2019) |
| **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/) | 8 | 0.29 Easy | 0.20 Low | 0.29 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=214960a2-2af7-4f33-8ce3-e5e1d2cf5a3f&source_detail=9702%2F42+March+2019) |
| **Q11** FRQ | [25.1 Energy of a photon](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/) | 9 | 0.31 Easy | 0.20 Low | 0.31 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=d06a45b1-31c7-481b-a293-86097351bd2f&source_detail=9702%2F42+March+2019) |
| **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 | 0.27 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e80bf1ed-6386-4b1b-9434-7ee65ca27999&question_id=1d862816-3bae-4e84-adc2-8f2f9eb0be6f&source_detail=9702%2F42+March+2019) |

## 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/)
- [10.1 Equation of state](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/equation-of-state/)
- [10.2 Kinetic theory of gases](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/kinetic-theory-of-gases/)
- [1.3 The Avogadro constant](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [11.2 Temperature scales](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/temperature-scales/)
- [13.1 Simple harmonic oscillations](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/simple-harmonic-oscillations/)
- [16.4 Relative merits of channels of communication](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [16.5 Attenuation](https://www.examsci.com/topics/cie-ial/physics/9702-paper-4/)
- [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/)
- [17.3 Electric forces between point charges](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-4/2019-october-november-9702-41/) — October/November 2019 — 12 questions · 100 marks — Free
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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 44 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 42.0% Easy, 55.0% 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.

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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-4/2019-march-9702-42/