Cambridge International AS & A Level

PHYSICS 9702/37
Paper 3 Advanced Practical Skills 1 May/June 2025
MARK SCHEME
Maximum Mark: 40

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the May/June 2025 series for most
Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level
components.

This document consists of 12 printed pages.

© Cambridge University Press & Assessment 2025 [Turn over

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Generic Marking Principles

These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptions for a question. Each question paper and mark scheme will also comply with these
marking principles.

GENERIC MARKING PRINCIPLE 1:

Marks must be awarded in line with:

• the specific content of the mark scheme or the generic level descriptors for the question
• the specific skills defined in the mark scheme or in the generic level descriptors for the question
• the standard of response required by a candidate as exemplified by the standardisation scripts.

GENERIC MARKING PRINCIPLE 2:

Marks awarded are always whole marks (not half marks, or other fractions).

GENERIC MARKING PRINCIPLE 3:

Marks must be awarded positively:

• marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond
the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
• marks are awarded when candidates clearly demonstrate what they know and can do
• marks are not deducted for errors
• marks are not deducted for omissions
• answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.

GENERIC MARKING PRINCIPLE 4:

Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

© Cambridge University Press & Assessment 2025 Page 2 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
GENERIC MARKING PRINCIPLE 5:

Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).

GENERIC MARKING PRINCIPLE 6:

Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.

Science-Specific Marking Principles

1 Examiners should consider the context and scientific use of any keywords when awarding marks. Although keywords may be present, marks
should not be awarded if the keywords are used incorrectly.

2 The examiner should not choose between contradictory statements given in the same question part, and credit should not be awarded for
any correct statement that is contradicted within the same question part. Wrong science that is irrelevant to the question should be ignored.

3 Although spellings do not have to be correct, spellings of syllabus terms must allow for clear and unambiguous separation from other
syllabus terms with which they may be confused (e.g. ethane / ethene, glucagon / glycogen, refraction / reflection).

4 The error carried forward (ecf) principle should be applied, where appropriate. If an incorrect answer is subsequently used in a scientifically
correct way, the candidate should be awarded these subsequent marking points. Further guidance will be included in the mark scheme
where necessary and any exceptions to this general principle will be noted.

5 ‘List rule’ guidance

For questions that require n responses (e.g. State two reasons …):

• The response should be read as continuous prose, even when numbered answer spaces are provided.
• Any response marked ignore in the mark scheme should not count towards n.
• Incorrect responses should not be awarded credit but will still count towards n.
• Read the entire response to check for any responses that contradict those that would otherwise be credited. Credit should not be
awarded for any responses that are contradicted within the rest of the response. Where two responses contradict one another, this
should be treated as a single incorrect response.
• Non-contradictory responses after the first n responses may be ignored even if they include incorrect science.

© Cambridge University Press & Assessment 2025 Page 3 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
6 Calculation specific guidance

Correct answers to calculations should be given full credit even if there is no working or incorrect working, unless the question states ‘show
your working’.

For questions in which the number of significant figures required is not stated, credit should be awarded for correct answers when rounded
by the examiner to the number of significant figures given in the mark scheme. This may not apply to measured values.

For answers given in standard form (e.g. a  10n) in which the convention of restricting the value of the coefficient (a) to a value between 1
and 10 is not followed, credit may still be awarded if the answer can be converted to the answer given in the mark scheme.

Unless a separate mark is given for a unit, a missing or incorrect unit will normally mean that the final calculation mark is not awarded.
Exceptions to this general principle will be noted in the mark scheme.

7 Guidance for chemical equations

Multiples / fractions of coefficients used in chemical equations are acceptable unless stated otherwise in the mark scheme.

State symbols given in an equation should be ignored unless asked for in the question or stated otherwise in the mark scheme.

© Cambridge University Press & Assessment 2025 Page 4 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Annotations guidance for centres

Examiners use a system of annotations as a shorthand for communicating their marking decisions to one another. Examiners are trained during the
standardisation process on how and when to use annotations. The purpose of annotations is to inform the standardisation and monitoring
processes and guide the supervising examiners when they are checking the work of examiners within their team. The meaning of annotations and
how they are used is specific to each component and is understood by all examiners who mark the component.

We publish annotations in our mark schemes to help centres understand the annotations they may see on copies of scripts. Note that there may
not be a direct correlation between the number of annotations on a script and the mark awarded. Similarly, the use of an annotation may not be an
indication of the quality of the response.

The annotations listed below were available to examiners marking this component in this series.

Annotations

Annotation Meaning

arithmetic error

AWK awkward scale used on graph

benefit of the doubt given

contradiction in response, mark not awarded

correct point or mark awarded

error carried forward applied

FO false origin used on graph

incorrect point or mark not awarded

information missing or insufficient for credit

power of ten error

© Cambridge University Press & Assessment 2025 Page 5 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Annotation Meaning

RO read-off from graph

SH supervisor’s help given

SR supervisor’s report taken into account

SV supervisor’s value/sample results taken into account

transcription error

value in range

OOR value out of range

© Cambridge University Press & Assessment 2025 Page 6 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Question Answer Marks

1(a) Value of E to the nearest 0.001 V with unit. 1

1(b) Value of L with unit in the range 25.0–35.0 cm and V ˂ E. 1

1(c) Six sets of readings of L (different values) and V with correct trend (L increases as V decreases) and without help from 4
Supervisor scores 4 marks, five sets scores 3 marks, etc.

Range of L: Lmin ⩽ 35.0 cm and Lmax ⩾ 80.0 cm. 1

Column headings: 1
Each column heading must contain a quantity and a unit where appropriate.
E –V
The presentation of quantity and unit must conform to accepted scientific convention e.g. / V cm–1.
L

Consistency: All values of L must be to the nearest mm. 1

Significant figures: 1
E –V
All values of must be given to 3 or 4 significant figures.
L

Calculation: 1
E –V
Correct calculation of .
L

© Cambridge University Press & Assessment 2025 Page 7 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Question Answer Marks

1(d)(i) Axes: 1
Axes must be labelled with the required quantities.
Scales must be chosen so that the plotted points occupy at least half the graph grid in both the x and y directions.
Scale markings are no more than 2 cm (one large square) apart.
Sensible scales must be used, no awkward scales (e.g. 3:10 or fractions).

Plotting of points: 1
All observations in the table must be plotted on the grid.
Diameter of plotted points must be ⩽ half a small square.
Points must be plotted to an accuracy of half a small square in both x and y directions.

Quality: 1
Trend of points must be positive.
All points in the table (at least 5 points) must be plotted on the grid for this mark to be awarded.
It must be possible to draw a straight line that is within  0.02 V on the V-axis of all plotted points.

1(d)(ii) Line of best fit: 1

‘Best fit’ is judged by the balance of all points on the grid (at least 5 points) about the candidate’s line.
There must be an even distribution of points either side of the line along the full length.
Lines must not be kinked or thicker than half a square.

Some candidates may choose to identify an anomalous point. If 6 or more points are plotted and they identify one point as
anomalous (e.g. by circling or labelling) then this point is to be disregarded when judging the line of best fit.

1(d)(iii) Gradient: 1
The hypotenuse of the triangle used must be greater than half the length of the drawn line.
Both read-offs must be accurate to half a small square in both the x and y directions.
Method of calculation must be correct, not x / y.
Gradient sign on answer line must be consistent with graph drawn.

y-intercept: 1
Intercept read directly from the graph, with read-off at x = 0, accurate to half a small square in y direction.
or
Correct read-off from a point on the line is substituted into y = mx + c or an equivalent expression.
Read-off accurate to half a small square in both x and y directions.

© Cambridge University Press & Assessment 2025 Page 8 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Question Answer Marks

1(e) P = candidate’s gradient value and Q = –candidate’s intercept value. 1

Values must not be written as fractions or given to only one significant figure.

Units for P: cm–1 or m–1 consistent with their readings 1

and
units for Q: V cm–1 or V m–1 consistent with their readings.

1(f) Line W of larger gradient on left of original line, not crossing on graph grid. 1

© Cambridge University Press & Assessment 2025 Page 9 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Question Answer Marks

2(a)(i) Final value of d in the range 1.6–2.6 cm with unit and raw value(s) to the nearest mm. 1

2(a)(ii) Percentage uncertainty based on absolute uncertainty in d in range 2–5 mm. 1

Correct method of calculation to find percentage uncertainty e.g. (absolute uncertainty / value from (a)(i))  100.
If repeated readings have been taken, then the uncertainty can be half the range (but not zero) if the working is clearly
shown.

2(b)(i) Value of x in the range 65.0–75.0 cm to the nearest mm. 1

2(b)(ii) (N = ) 4.95 1

2(c) Value of T (on answer line) in the range 0.70–1.20 s with unit. 1

Repeats: At least two measurements of nT where n ⩾ 5. 1

2(d) Second values of d and x. 1

Second value of T. 1

Second value of T ˂ first value of T. 1

2(e)(i) Two values of k calculated correctly. 1

The final k values must not be written as fractions or given to only one significant figure.

2(e)(ii) Justification for significant figures in k linked to significant figures in time, d and x. 1

2(f) Correct calculation of percentage difference between candidate’s two k values. 1

Comparison of percentage difference with 15%, leading to a consistent conclusion.

© Cambridge University Press & Assessment 2025 Page 10 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Question Answer Marks

2(g)(i) A Two (sets of) readings are not enough to draw a (valid) conclusion (not “not enough for accurate results”, “few 4
readings”).

B Difficult to measure d with a reason e.g. parallax error (with sphere on rule) / ruler not precise an instrument to use
or
large percentage uncertainty in d.

C Difficult to measure x with a reason e.g. difficult to locate centres of rods / rods may not be parallel.

D Difficult to measure time or T with a reason e.g. judge start / end / completion of an oscillation.

E Difficulty with the chain during oscillation e.g. chain slips (along rod) during oscillation / chain falls off the rod whilst
oscillating / other modes of oscillation of the chain / movement of rods or stands during oscillation of the chain / difficult
to maintain x to be constant whilst chain oscillating.

F Difficulty with sphere e.g. not a uniform sphere / sphere falling off (paper clip) / sphere changes shape when handled.

1 mark for each point up to a maximum of 4.

© Cambridge University Press & Assessment 2025 Page 11 of 12

9702/37 Cambridge International AS & A Level – Mark Scheme May/June 2025
PUBLISHED
Question Answer Marks

2(g)(ii) A Take more readings (for different values of x and n) and plot a graph or take more readings and compare k values (not 4
“repeat readings” on its own).

B Use (vernier/digital) calipers

or
use blocks (either side of sphere) with detail.

C Clamp rule (to measure x).

D Video / film / record with timer in view or use marker at the centre of the oscillation.

E Workable method to prevent chain from slipping e.g. groove in rod

or
workable method to mitigate unwanted modes of oscillation e.g. increase the number of paper clips or reduce the
distance between the rods
or
use metal rods
or
clamp stands (to the bench).

F Use a stiffer material for the balls e.g. use baked clay / metal balls
or
use a mould / preformed balls

1 mark for each point up to a maximum of 4.

© Cambridge University Press & Assessment 2025 Page 12 of 12