Cambridge Physics 9702 Paper 3: Current Advanced Practical Skills Guide

Q: What does Cambridge International Physics 9702 Paper 3 assess?
A: Paper 3 is the two-hour Advanced Practical Skills laboratory paper. Its two questions assess manipulation, measurement, observation, data presentation, graphing, analysis, conclusions, uncertainty, limitations, and improvements.

TL;DR
Paper 3 has 40 marks and contributes 23% of AS Level or 11.5% of A Level. It contains two 20-mark questions, each allocated about one hour. Question 1 requires a graph; Question 2 may or may not require one and includes evaluation of an inaccurate method.

Last reviewed: 19 July 2026. This guide follows Cambridge's current 2025-2027 Physics 9702 specification. It describes the published assessment contract and skills without predicting the exact apparatus, measurements, relationship, or topic in a future paper.

1. Paper 3 at a glance

Paper 3 is one of the three AS components. It can also contribute to the full A Level through a valid staged entry or by taking all five components in one series. Paper 5 is an additional written Planning, Analysis and Evaluation component for the A Level route; it does not replace Paper 3.

2. Confirm the entry and laboratory arrangements

Ask the school or examination centre to confirm the Physics 9702 syllabus, series, administrative zone, Paper 3 component code, entry route, reporting time, permitted items, local instructions, and any current carry-forward or centre deadlines.

Paper-specific apparatus and materials appear in Confidential Instructions sent to centres. Centres provide the apparatus and hold responsibility for laboratory safety and local first-aid rules. Cambridge's list of regularly used items is not exhaustive and is not a candidate packing list.

3. The two published questions

The questions are set in different areas of physics. No prior knowledge of the theory is required, and Cambridge supplies information needed for an unfamiliar context.

The specification does not promise mechanics, oscillations, electricity, optics, or any other named topic in a particular question.

4. Current mark allocation

The movable marks mean that the detailed split can vary. Do not infer one fixed mark count for a particular apparatus, graph step, limitation, or improvement.

5. Measurements, range, and tables

Candidates should be able to set up apparatus, follow written instructions and diagrams including circuits, collect an appropriate quantity of data, repeat readings where appropriate, and use common analogue and digital instruments.

Cambridge specifically includes timing an appropriate number of consecutive oscillations when measuring a period. This is a published capability, not a guarantee that an oscillation experiment will appear.

Measurements should span the largest possible range permitted by the instructions and equipment. Quality is judged only to the extent that the candidate can affect it; Cambridge allows for limits imposed by the required method or apparatus.

Tables and calculations should:

• use one results table prepared before readings are taken;
• include raw and calculated values;
• put both quantity and unit in each heading using accepted conventions;
• record raw values of the same quantity at consistent, instrument-supported precision;
• show calculation working and key reasoning;
• use and justify suitable significant figures.

For a calculated value other than addition or subtraction, if the least precise measured input has n significant figures, n or n + 1 is normally appropriate. The correct choice may vary down a calculated column when the measured precision varies.

6. Current graph requirements

The published graph rules include:

• label each axis with quantity and unit;
• make the points occupy at least half the grid in both directions;
• use a false origin where appropriate;
• choose readable scales, commonly 1, 2, or 5 units per 2-centimetre square;
• place regularly spaced numerical labels along each axis at least every 2 centimetres;
• plot every point to better than 1-millimetre accuracy;
• use a fine cross or encircled dot smaller than 1 millimetre;
• draw a straight best-fit line or smooth curve with an even point distribution;
• identify any point excluded as anomalous;
• draw a tangent where the curved trend and question require it.

For a gradient, the two chosen points must be separated by more than half the length of the line drawn. Candidates may relate a straight-line graph to y = mx + c, determine gradient or intercept, and calculate an intercept from a point and gradient when a false origin prevents direct reading.

Use the graph treatment supported by the data and question. A single straight best-fit line, tangent, false origin, or curve is not mandatory in every investigation.

7. Uncertainty and conclusions

Candidates should be able to estimate absolute measurement uncertainty, express it as an absolute or percentage uncertainty, convert between the two forms, and use half the range as the absolute uncertainty of repeated readings where appropriate.

For a relationship containing a constant, Cambridge may ask candidates to calculate the percentage difference between constant values, compare it with a given percentage uncertainty, and decide whether the data supports the relationship.

A conclusion may determine a constant, state whether data supports a hypothesis, or make a prediction. Use the measured values, graph, uncertainty, and relationship supplied rather than a generic claim that close values automatically agree.

8. Limitations and improvements

Question 2 asks candidates to evaluate the prescribed inaccurate method. A source-aligned response:

1. names the quantity or step being limited;
2. gives a physical reason for the uncertainty;
3. identifies the most significant sources;
4. proposes a realistic school-laboratory modification;
5. explains how the modification improves accuracy or extends the investigation.

An improvement may use different apparatus or a different procedure, but not a different experiment. It should be achievable in practice. A change that could already have been made with the supplied apparatus while following the instructions will not normally gain credit.

Do not rely on a topic phrase bank. Damping, electrical heating, alignment, parallax, reaction time, and zero error are relevant only when they actually limit the supplied setup or measurement.

9. A source-bounded preparation method

This is study advice, not a Cambridge rule: verify the route, then practise supervised measurement, consistent tables, instrument-supported precision, full graph construction, uncertainty reasoning, evidence-led conclusions, and method-specific improvements before timed papers.

Cambridge's course guidance says learners should spend at least 20 percent of course time doing practical work individually or in small groups, excluding demonstrations. This is a course-design statement, not a guaranteed number of sessions for one candidate or a requirement to use a commercial laboratory provider.

10. What this guide does not establish

The specification does not fix a future topic, apparatus, values, graph shape, limitation, or improvement. It does not guarantee weekly mechanics, oscillations, electricity, or optics work; one universal instrument-precision list; a fixed mock or laboratory count; or grade improvement from tuition or any other format.

See the Physics 9702 Paper 5 guide; its body remains a separate fact-check scope.

References

1. Cambridge International, Physics 9702 syllabus, 2025-2027.
2. Cambridge International, Physics 9702 overview.