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Cambridge International AS & A Level
PHYSICS 9702/11
Paper 1 Multiple Choice May/June 2021
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.
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 2021 series for most Cambridge
IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.

9702/11 Cambridge International AS & A Level – Mark Scheme
PUBLISHED
May/June 2021
© UCLES 2021 Page 2 of 3
Question Answer Marks
1 A 1
2 D 1
3 C 1
4 B 1
5 D 1
6 C 1
7 C 1
8 D 1
9 A 1
10 C 1
11 A 1
12 D 1
13 C 1
14 D 1
15 A 1
16 D 1
17 A 1
18 B 1
19 B 1
20 C 1
21 D 1
22 B 1
23 A 1
24 A 1
25 A 1
26 B 1
27 A 1
28 B 1

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May/June 2021
29 B 1
30 D 1
31 C 1
32 A 1
33 C 1
34 B 1
35 D 1
36 C 1
37 B 1
38 B 1
39 B 1
40 A 1

PHYSICS 9702/12
MARK SCHEME
Maximum Mark: 40
Published
examination.
Teachers.

PUBLISHED
May/June 2021
1 D 1
2 B 1
3 D 1
4 D 1
5 D 1
6 D 1
7 B 1
8 C 1
9 B 1
10 D 1
11 A 1
12 C 1
13 B 1
14 C 1
15 A 1
16 A 1
17 D 1
18 D 1
19 A 1
20 D 1
21 B 1
22 A 1
23 B 1
24 A 1
25 B 1
26 C 1
27 B 1
28 B 1

PUBLISHED
May/June 2021
29 C 1
30 A 1
31 D 1
32 A 1
33 A 1
34 B 1
35 A 1
36 C 1
37 A 1
38 C 1
39 C 1
40 A 1

PHYSICS 9702/13
MARK SCHEME
Maximum Mark: 40
Published
examination.
Teachers.

PUBLISHED
May/June 2021
1 C 1
2 C 1
3 A 1
4 B 1
5 B 1
6 D 1
7 C 1
8 C 1
9 D 1
10 B 1
11 A 1
12 B 1
13 A 1
14 A 1
15 B 1
16 D 1
17 C 1
18 B 1
19 D 1
20 D 1
21 C 1
22 B 1
23 A 1
24 A 1
25 D 1
26 B 1
27 C 1
28 B 1

PUBLISHED
May/June 2021
29 A 1
30 B 1
31 D 1
32 A 1
33 C 1
34 A 1
35 A 1
36 C 1
37 B 1
38 C 1
39 C 1
40 D 1

PHYSICS 9702/21
Paper 2 AS Level Structured Questions May/June 2021
MARK SCHEME
Maximum Mark: 60
Published
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.
Teachers.

PUBLISHED
May/June 2021
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 descriptors 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.
Marks awarded are always whole marks (not half marks, or other fractions).
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.
Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.

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May/June 2021
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).
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.

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May/June 2021
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.

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May/June 2021
Abbreviations
/ Alternative and acceptable answers for the same marking point.
( ) Bracketed content indicates words which do not need to be explicitly seen to gain credit but which indicate the context for an answer.
The context does not need to be seen but if a context is given that is incorrect then the mark should not be awarded.
___ Underlined content must be present in answer to award the mark. This means either the exact word or another word that has the
same technical meaning.
Mark categories
B marks These are independent marks, which do not depend on other marks. For a B mark to be awarded, the point to which it refers must be
seen specifically in the candidate’s answer.
M marks These are method marks upon which A marks later depend. For an M mark to be awarded, the point to which it refers must be seen
specifically in the candidate’s answer. If a candidate is not awarded an M mark, then the later A mark cannot be awarded either.
C marks These are compensatory marks which can be awarded even if the points to which they refer are not written down by the candidate,
providing subsequent working gives evidence that they must have known them. For example, if an equation carries a C mark and the
candidate does not write down the actual equation but does correct working which shows the candidate knew the equation, then the
C mark is awarded.
If a correct answer is given to a numerical question, all of the preceding C marks are awarded automatically. It is only necessary to
consider each of the C marks in turn when the numerical answer is not correct.
A marks These are answer marks. They may depend on an M mark or allow a C mark to be awarded by implication.
Annotations
 Indicates the point at which a mark has been awarded.
X Indicates an incorrect answer or a point at which a decision is made not to award a mark.
XP Indicates a physically incorrect equation (‘incorrect physics’). No credit is given for substitution, or subsequent arithmetic, in a
physically incorrect equation.

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May/June 2021
ECF Indicates ‘error carried forward’. Answers to later numerical questions can always be awarded up to full credit provided they are
consistent with earlier incorrect answers. Within a section of a numerical question, ECF can be given after AE, TE and POT errors,
but not after XP.
AE Indicates an arithmetic error. Do not allow the mark where the error occurs. Then follow through the working/calculation giving full
subsequent ECF if there are no further errors.
POT Indicates a power of ten error. Do not allow the mark where the error occurs. Then follow through the working/calculation giving full
TE Indicates incorrect transcription of the correct data from the question, a graph, data sheet or a previous answer. For example, the
value of 1.6 × 10–19 has been written down as 6.1 × 10–19 or 1.6 × 1019.
Do not allow the mark where the error occurs. Then follow through the working/calculation giving full subsequent ECF if there are no
further errors.
SF Indicates that the correct answer is seen in the working but the final answer is incorrect as it is expressed to too few significant
figures.
BOD Indicates that a mark is awarded where the candidate provides an answer that is not totally satisfactory, but the examiner feels that
sufficient work has been done (‘benefit of doubt’).
CON Indicates that a response is contradictory.
I Indicates parts of a response that have been seen but disregarded as irrelevant.
M0 Indicates where an A category mark has not been awarded due to the M category mark upon which it depends not having previously
been awarded.
^ Indicates where more is needed for a mark to be awarded (what is written is not wrong, but not enough). May also be used to
annotate a response space that has been left completely blank.
SEEN Indicates that a page has been seen.

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May/June 2021
Question Answer Mark
1(a) mass / volume B1
1(b)(i) absolute uncertainty = 4.0 × (5 / 100)
= (±) 0.2 cm
B1
1(b)(ii) percentage uncertainty = 2 + 4 + (5 × 2) C1
= (±) 16% A1
1(c) p = F / A or p = W / A C1
p = (19.5 × 10–3 × 9.81) / (4.0 × 10–2)2 C1
= 120 Pa A1

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May/June 2021
2(a)(i) P = Fv C1
= 18 × 1.4
= 25 W
A1
2(a)(ii) a = F / m C1
a = 18 / 72 = 0.25 (ms–2)
t = 1.4 / 0.25
C1
= 5.6 s A1
2(b)(i) a = (54 – 18) / 72 or 36 / 72 (= 0.50 ms–2) C1
v2 = 2 × 0.50 × 9.5 C1
v = 3.1 m s–1 A1
2(b)(ii) W = 54 × 9.5
= 510 J
A1
2(b)(iii) curved line from the origin M1
gradient of line increases A1
2(c) (force due to) air resistance increases/changes/not constant or air resistance increases with speed B1

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May/June 2021
3(a) solid straight line drawn between centre of sphere at X and at Y B1
3(b) p = mv or 0.72 = mv C1
E = ½mv2 or 0.86 = ½mv2 C1
(m =) 0.722 / (2 × 0.86) = 0.30 (kg)
or
v = 2EK / p
v = (0.86 × 2) / 0.72 = 2.4 (to 2 s.f.)
m = 0.72 / 2.4 = 0.30 (kg)
A1
3(c) (Δ)E = mg(Δ)h C1
h = 0.86 / (0.30 × 9.81)
= 0.29 m
A1
3(d) cosθ = (0.93 – 0.29) / 0.93 so θ = 47° A1
3(e) moment = (0.30 × 9.81) × 0.93 × (sin 47° or cos 43°)
or
moment = (0.30 × 9.81) × [0.932 – (0.93 – 0.29)2]0.5
C1
= 2.0 N m A1

PUBLISHED
May/June 2021
3(f) there is a resultant force (acting on sphere)
or
there is a resultant moment (about P acting on pendulum)
(so) not in equilibrium
B1
4(a) distance moved by wavefront/energy during one cycle/oscillation/period (of source)
or
minimum distance between two wavefronts
or
distance between two adjacent wavefronts
B1
4(b) v = λ / T
or
v = fλ and f = 1 / T
C1
T = 460 × 10–9 / 3.00 × 108 C1
= 1.5 × 10–15 s A1
4(c) waves pass through/enter the slit(s) B1
waves spread (into geometric shadow) B1
4(d)(i) nλ = d sinθ C1
G = sinθ / λ
d = 4 / G
A1
4(d)(ii) straight line from 400 nm to 700 nm that is always below printed line M1
straight line has smaller gradient than printed line and is 5 small squares high at wavelength of 700 nm A1

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May/June 2021
5(a) sum of e.m.f.(s) = sum of p.d.(s)
or
(algebraic) sum of e.m.f.(s) and p.d.(s) is zero
M1
around a loop/around a closed circuit A1
5(b)(i) I = 1.8 / 0.90
= 2.0 A
A1
5(b)(ii) Q = It C1
number = (2.0 × 45) / 1.60 × 10–19
= 5.6 × 1020
A1
5(b)(iii) 4.0 = 1.8 + [2.0 × (0.35 + R)]
or
4.0 = 2.0 × (0.90 + 0.35 + R)
C1
R = 0.75 Ω A1
5(c)(i) 1.2 / 1.8 = 0.30 / L C1
L = 0.45 m A1
5(c)(ii) p.d. across XY decreases/p.d. across XP decreases B1
(so) P is moved towards Y/away from X/to the right B1

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May/June 2021
6(a)(i) (electron) neutrino B1
6(a)(ii) weak (nuclear force/interaction) B1
6(a)(iii) β+ (particle) B1
6(a)(iv) (quark structure is) up up down or uud B1
(2 / 3)e + (2 / 3)e – (1 / 3)e = (+)e B1
6(a)(v) up up down changes to up down down or uud → udd
or
up changes to down or u → d
B1
6(b)(i) F = Eq C1
ratio = 6 / 8
= 0.75
A1
6(b)(ii) ratio = 0.75 × (16 / 12)
= 1.0
A1
6(b)(iii) horizontal straight line at a non-zero value of a B1

PHYSICS 9702/22
MARK SCHEME
Maximum Mark: 60
Published
Teachers.

PUBLISHED
May/June 2021
marking principles.
descriptors.

PUBLISHED
May/June 2021
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.

PUBLISHED
May/June 2021
your working’.

PUBLISHED
May/June 2021
Abbreviations
( ) Bracketed content indicates words which do not need to be explicitly seen to gain credit but which indicate the context for an answer.
The context does not need to be seen but if a context is given that is incorrect then the mark should not be awarded.
___ Underlined content must be present in answer to award the mark. This means either the exact word or another word that has the same
technical meaning.
Mark categories
candidate does not write down the actual equation but does correct working which shows the candidate knew the equation, then the C
mark is awarded.
Annotations
XP Indicates a physically incorrect equation (‘incorrect physics’). No credit is given for substitution, or subsequent arithmetic, in a
physically incorrect equation.

PUBLISHED
May/June 2021
consistent with earlier incorrect answers. Within a section of a numerical question, ECF can be given after AE, TE and POT errors, but
not after XP.
TE Indicates incorrect transcription of the correct data from the question, a graph, data sheet or a previous answer. For example, the
value of 1.6 × 10–19 has been written down as 6.1 × 10–19 or 1.6 × 1019.
further errors.
SF Indicates that the correct answer is seen in the working but the final answer is incorrect as it is expressed to too few significant figures.
been awarded.
^ Indicates where more is needed for a mark to be awarded (what is written is not wrong, but not enough). May also be used to annotate
a response space that has been left completely blank.

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May/June 2021
1(a) acceleration: vector
electrical resistance: scalar
momentum: vector
1 mark for two correct, 2 marks for all three correct
B2
1(b) resultant force (in any direction) is zero B1
resultant torque/moment (about any point) is zero B1
1(c)(i) upthrust = ρg(∆)h× A C1
= (1.00 × 103 × 9.81 × 0.190) × 0.0230
= 42.9 N
A1
1(c)(ii) (T =) 43 – 28 = 15 (N)
or
(T =) 42.9 – 28 = 14.9 or 15 (N)
A1
1(c)(iii) σ = F / A or T / A C1
= 15 / (3.2 × 10–6)
= 4.7 × 106 Pa
A1
1(c)(iv) upthrust (on cylinder) increases (and weight constant) B1
tension/stress increases and (so) strain energy increases B1

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May/June 2021
2(a) v2 = u2 + 2as
u2 = 8.72 – (2 × 9.81 × 1.5)
C1
u = 6.8 m s–1 A1
2(b) (magnitude of) force on ball (by ground) equal to force on ground (by ball) B1
(direction of) force on ball (by ground) opposite to force on ground (by ball) B1
2(c)(i) (p = ) 0.059 × 8.7 or 0.059 × 5.4 C1
change in momentum = 0.059 (8.7 + 5.4)
= 0.83 N s
A1
2(c)(ii) resultant force = 0.83 / 0.091 or 0.059 [(8.7 + 5.4) / 0.091]
= 9.1 N
A1
2(c)(iii) (W =) 0.059 × 9.81 C1
(W =) 0.58 (N)
force = 9.1 + 0.58
= 9.7 N
A1
2(d) straight line with a positive gradient and starting from a non-zero value of speed at t = 0 and ending when t = T B1
2(e) air resistance increases B1
resultant force/acceleration decreases so gradient (of curve) decreases B1

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May/June 2021
3(a) (Δ)E= mg(Δ)h or W(∆)h C1
= 330 × (4.0 – 1.1)
= 960 J
A1
3(b) (work =) 960 – 540
(= 420 J)
C1
distance moved = (960 – 540) / 52
= 8.1 m
A1
3(c)(i) E = ½mv2 C1
540 = ½ × (330 / 9.81) × v2
v = 5.7 m s–1
A1
3(c)(ii) speed = horizontal component of velocity
= 5.7 × cos41°
C1
= 4.3 m s–1 A1

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May/June 2021
4(a) time for one oscillation/vibration/cycle
or
time between adjacent wavefronts (passing the same point)
or
shortest time between two wavefronts (passing the same point)
B1
4(b) (when two or more) waves meet/overlap (at a point) B1
(resultant) displacement is sum of the individual displacements B1
4(c)(i) microwave(s) B1
4(c)(ii) v = λ / T
or
v = fλ and f = 1/T
C1
T= 0.040 / 3.00 × 108 C1
= 1.33 × 10–10 (s)
= 1.33 × 10–10 / 10–12 (ps)
= 130 ps
A1
4(c)(iii) (1.380 – 1.240) / 0.040 = 3.5
or
1.380 / 0.040 – 1.240 / 0.040 = 3.5
A1
4(c)(iv) phase difference = 1260° or 180° A1
4(c)(v) (always) zero A1
4(c)(vi) increase in distance between (adjacent intensity) maxima/minima A1

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May/June 2021
5(a) volt / ampere B1
5(b) R = ρL / A B1
(A = V / L)
(so) R = ρL2 / V (with ρ and V constant so R ∝ L2)
B1
5(c)(i) E = 2.4 V A1
5(c)(ii) P= VI or I2R or V2 / R C1
= 1.3 × 5.0 or 5.02 × 0.26 or 1.32 / 0.26 C1
= 6.5 W A1
5(c)(iii) (–) internal resistance or (–) r B1

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May/June 2021
6(a) the nucleus is charged B1
the majority of the mass (of atom) is in the nucleus B1
6(b) made up of quarks (so) not a fundamental particle B1
6(c) (Q =) 6.9 × 10–9 × 60 C1
number = (6.9 × 10–9 × 60) / (2 × 1.60 × 10–19) C1
= 1.3 × 1012 A1
6(d) (magnitude of electric) force is constant B1
(so magnitude of) acceleration is constant B1
6(e) (nuclei have) same charge/same number of protons B1
(so) same (magnitude of) force B1

PHYSICS 9702/23
MARK SCHEME
Maximum Mark: 60
Published
Teachers.

PUBLISHED
May/June 2021
marking principles.
descriptors.

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May/June 2021
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).
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.

PUBLISHED
May/June 2021
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.

PUBLISHED
May/June 2021
Abbreviations
( ) Bracketed content indicates words which do not need to be explicitly seen to gain credit but which indicate the context for an answer. The
context does not need to be seen but if a context is given that is incorrect then the mark should not be awarded.
___ Underlined content must be present in answer to award the mark. This means either the exact word or another word that has the same
technical meaning.
Mark categories
candidate does not write down the actual equation but does correct working which shows the candidate knew the equation, then the
C mark is awarded.
Annotations
XP Indicates a physically incorrect equation (‘incorrect physics’). No credit is given for substitution, or subsequent arithmetic, in a physically
incorrect equation.

PUBLISHED
May/June 2021
consistent with earlier incorrect answers. Within a section of a numerical question, ECF can be given after AE, TE and POT errors, but
not after XP.
TE Indicates incorrect transcription of the correct data from the question, a graph, data sheet or a previous answer. For example, the value
of 1.6 × 10–19 has been written down as 6.1 × 10–19 or 1.6 × 1019.
further errors.
SF Indicates that the correct answer is seen in the working but the final answer is incorrect as it is expressed to too few significant figures.
been awarded.
^ Indicates where more is needed for a mark to be awarded (what is written is not wrong, but not enough). May also be used to annotate
a response space that has been left completely blank.

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May/June 2021
1(a)(i) two correct scalar quantities e.g. time, mass, distance, temperature B1
two correct vector quantities e.g. force, acceleration, velocity, displacement B1
1(a)(ii) magnitude B1
unit B1
1(b)(i) north component of velocity = 11 m s–1 A1
east component of velocity = 7.5 m s–1 A1
1(b)(ii) velocity = 7.5 – 2.7
= 4.8 m s–1
A1
1(b)(iii) velocity = √(112 + 4.82) C1
= 12 m s–1 A1
1(b)(iv) angle = tan–1 (4.8 / 11) C1
= 24° A1

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May/June 2021
2(a) change in velocity / time (taken) B1
2(b)(i) air resistance increases (with speed/with time) B1
resultant force decreases (as speed increases/with time) so acceleration decreases (as speed increases/with time) B1
when air resistance equals the weight the speed/velocity/v becomes constant B1
2(b)(ii) speed = 36 m s–1 A1
2(b)(iii) height given by area under the curve C1
height = 950 m
Round to two significant figures and award 2 marks for a value in the range 920–980 m and 1 mark for a value in the range
900–910 m or 990–1000 m.
A2
2(b)(iv) line starting at (0, 9.8) B1
curve with negative gradient between t = 0 and t = 20 s B1
line showing zero acceleration between t = 20 s and t = 30 s B1

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May/June 2021
3(a) force × distance M1
perpendicular distance of (line of action of) force from the point A1
3(b)(i) distance moved by pointer = 123 – 86 (= 37 mm) C1
(extension =) 37 × (1.8 / 52.6) = 1.3 (mm)
or
sin or tan θ = 37 / 526 (so θ = 4.0° so extension =) sin or tan θ × 18 = 1.3 (mm)
A1
3(b)(ii) moment = 0.472 × 9.81 × 6.2 × 10–2 C1
= 0.29 N m A1
3(b)(iii) (Δ)F × 1.8 × 10–2 = 0.29 C1
ΔF = 16 N A1
3(b)(iv) k = F / x C1
= 16 / (1.3 × 10–3)
= 1.2 × 104 N m–1
A1

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May/June 2021
4(a) (when two or more) waves meet/overlap (at a point) B1
(resultant) displacement is sum of the individual displacements B1
4(b) intensity ∝ amplitude2 C1
maximum intensity = 9I A1
4(c)(i) x = λD / a C1
= (550 × 10–9 × 1.2) / (0.35 × 10–3) C1
= 1.9 × 10–3 m A1
4(c)(ii) red light has longer wavelength (than 550 nm) so distance (between fringes) increases B1

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May/June 2021
5(a) energy per unit charge B1
energy transferred by source driving charge around the complete circuit
or
energy transferred from other forms to electrical energy
B1
5(b) there is a p.d. across the internal resistance/r B1
change in current/I results in a change in p.d. across the internal resistance B1
V = E – p.d. across internal resistance
or
change in p.d. across r causes a change in V (as e.m.f. is constant)
B1
5(c)(i) E = 7.4 V A1
5(c)(ii) maximum current = 0.92 A A1
5(c)(iii) r = E / IMAX or (–)gradient C1
e.g. r = 7.4 / 0.92
= 8.0 Ω
A1
5(d) straight line with negative gradient that is smaller in magnitude than the original line B1
line which would have intercept on V-axis below the original line B1

PUBLISHED
May/June 2021
6(a)(i) up up down B1
6(a)(ii) up down down B1
6(a)(iii) (alpha-particle is) 2 protons and 2 neutrons C1
6 up, 6 down A1
6(b)(i) most of an atom is empty space
or
the nucleus (volume) is (very) small compared with the atom
B1
6(b)(ii) the nucleus is charged B1
the majority of the mass of atom is in the nucleus B1
6(c) F = Eq and a = F / m C1
a = Eq / m
ratio = (e / m) / (2e / 4m)
= 2
A1

PHYSICS 9702/31
Paper 3 Advanced Practical Skills 1 May/June 2021
MARK SCHEME
Maximum Mark: 40
Published
Teachers.

PUBLISHED
May/June 2021
marking principles.
descriptors.

PUBLISHED
May/June 2021

PUBLISHED
May/June 2021
your working’.

PUBLISHED
May/June 2021
1(a) Final value of L with unit and in the range 28.0–32.0 cm. 1
1(b) Raw value(s) of x and b to nearest mm and with units. 1
1(c) Six (or more) sets of readings of x and b (different values) with correct trend (as m decreases, x decreases and b increases)
and without help from Supervisor scores 5 marks, five sets scores 4 marks, etc.
5
Range: (mmax – mmin) ⩾ 70 g. 1
Column headings:
Each column heading must contain a quantity and a unit where appropriate.
The presentation of quantity and unit must conform to accepted scientific convention, e.g. 1/b / cm–1 or 1/b (1/cm).
1
Significant figures:
All values of 1 / b must be given to the same number of significant figures as, or one greater than, the number of significant
figures in raw b.
1
Calculation: Values of 1 / b are correct. 1
1(d)(i) Axes:
Sensible scales must be used, no awkward scales (e.g. 3:10 or fractions).
Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions
Axes must be labelled with the quantity that is being plotted.
Scale markings should be no more than three large squares apart.
1
Plotting of points:
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.
1
Quality:
All points in the table must be plotted (at least 5) on the grid.
Trend of points must be correct.
It must be possible to draw a straight line that is within ± 0.2 m–1 (± 0.002 cm–1) on the 1 / b axis (normally y-axis) of all
plotted points.
1

PUBLISHED
May/June 2021
1(d)(ii) Line of best fit:
Judge by balance of all points on the grid about the candidate’s line (at least 5 points). There must be an even distribution of
points either side of the line along the full length.
Allow one anomalous point only if clearly indicated by the candidate. There must be at least five points left after the
anomalous point is disregarded.
Lines must not be kinked or thicker than half a small square.
1
1(d)(iii) Gradient:
The hypotenuse of the triangle used must be greater than half the length of the drawn line.
Method of calculation must be correct, i.e. Δy /Δx.
Gradient sign on answer line matches graph drawn.
Both read-offs must be accurate to half a small square in both the x and y directions.
1
y-intercept:
Correct read-off from a point on the line and substituted into y = mx + c.
Read-off must be accurate to half a small square in both x and y directions.
or
Intercept read directly from the graph at x = 0, accurate to half a small square.
1
1(e) Value of P equal to candidate’s gradient and value of Q equal to candidate’s intercept.
Values must not be written as fractions.
1
Unit for P (e.g. cm–2) and unit for Q (e.g. cm–1) correct. 1
1(f) Line W shown with greater gradient. 1

PUBLISHED
May/June 2021
2(a) Value of d to the nearest mm with unit. 1
2(b) Correct calculation of temperature change Δθ. 1
2(c)(i) Value of h with unit. 1
D > d. 1
2(c)(ii) Percentage uncertainty based on absolute uncertainty Δh in the range 2–6 mm.
If repeat readings have been taken, then the absolute uncertainty can be half the range (but not zero) if the working is clearly
shown.
Correct method of calculation to obtain percentage uncertainty.
1
2(c)(iii) Correct calculation of C. 1
2(c)(iv) Justification for significant figures in C linked to s.f. in D and d or linked to s.f. in (D – d). 1
2(d) Second values of θ0 and θ. 1
Second values of h and D. 1
Temperature decreases in both experiments and second value of Δθ < first value of Δθ. 1
2(e)(i) Two values of k calculated correctly. The final k values must not be written as fractions. 1
2(e)(ii) Valid comment consistent with the calculated values of k, testing against a criterion stated by the candidate. 1

PUBLISHED
May/June 2021
2(f)(i) A Two readings are not enough to draw a (valid) conclusion (not “not enough for accurate results”, “few readings”).
B Difficult to measure h with reason, e.g. scale of ruler does not start at the end/opaque cup/water too hot/rule in water
changes water level.
C Difficult to measure D with reason, e.g. parallax.
D Large % uncertainty (error) in Δθ
or
thermometer is not precise enough to measure a small change in temperature.
E Difficulty with taking temperature at the end of the two-minute period with reason, e.g. cannot look at stop-watch and
thermometer simultaneously.
1 mark for each point up to a maximum of 4.
4
2(f)(ii) A Take more readings and plot a graph or take more readings and compare k values (not “repeat readings” on its own).
B Use a transparent cup/ruler without a space at end/measure (empty depth – depth to water surface) with detailed
description e.g. use rod at right angles to a rule across top of cup to reach water surface or cup bottom.
C To measure D or inside of cup, use calipers/dividers/vertical pointers/travelling microscope.
D Improved method to measure Δθ e.g. more precise thermometer/thermometer reading to 0.1 °C/thinner capillary in
thermometer/more sensitive thermometer
or
allow experiment to go on for more than two minutes.
E Method for simultaneous measurement of temperature and time e.g. sound to mark two-minute period/temperature
probe linked to data logger system/video with thermometer and timer in view.
4

PHYSICS 9702/32
MARK SCHEME
Maximum Mark: 40
Published
Teachers.

PUBLISHED
May/June 2021
marking principles.
descriptors.

PUBLISHED
May/June 2021

PUBLISHED
May/June 2021
your working’.

PUBLISHED
May/June 2021
1(a) Final value of sA to at least two significant figures and in the range 1.05–1.10mm. 1
Evidence that sA has been correctly calculated from a measurement of at least 10sA. 1
1(b) Value of G in range 0°–45°. 1
1(c) Six (or more) sets of readings of G and F (different values) with correct trend (F increases as G increases) and without help
from the Supervisor scores 3 marks, five sets scores 2 marks, four or fewer sets scores 1 mark.
3
Range: Gmin ⩽ 3° and Gmax ⩾ 17°. 1
Column headings:
Headings for sin F and sin (F–G) must have no unit.
The presentation of quantity and unit must conform to accepted scientific convention e.g. F / °.
1
Consistency: All values of raw G and raw F must be given to the nearest degree. 1
Values of sin F should be to the same number of significant figures as, or one greater than, the number of significant
figures in the corresponding value(s) of raw F.
1
Calculation: Values of sin (F–G) calculated correctly. 1

PUBLISHED
May/June 2021
1(d)(i) Axes:
Scales are chosen so that the plotted points occupy at least half the graph grid in both x and y directions
1
Plotting of points:
Diameter of plotted points are ⩽ half a small square.
Points must be plotted to an accuracy of half a small square.
1
Quality:
Trend of points on graph must be correct.
It must be possible to draw a straight line that is within ± 0.02 on the sin F axis of all plotted points.
1
Judge by balance of all points on the grid about the candidate’s line (at least 5 points). There must be an even distribution
of points either side of the line along the full length.
1
1(d)(iii) Gradient:
1
y-intercept:
or
1

PUBLISHED
May/June 2021
1(e) Value of p equal to candidate’s gradient and value of q equal to candidate’s intercept. Values must not be written as
fractions.
1
Values for p and q both given without a unit. 1
1(f) Correct calculation of sB using sB = psA. 1

PUBLISHED
May/June 2021
2(a)(i) Value of TV with unit and in range 0.20–0.40 s. 1
At least two measurements of nTV where n ⩾ 5. 1
2(a)(ii) Value for TS larger than TV. 1
2(b) Second values of TV and TS. 1
Second TS > first TS. 1
2(c)(i) Two values of TS
2 – TV
2 calculated correctly. 1
2(c)(ii) Justification based on significant figures in TS and TV. 1
2(c)(iii) Valid comment consistent with the calculated values of TS
2 – TV
2, testing against a criterion stated by the candidate. 1
2(d)(i) Value for x1 in range 4.0–6.0 cm. 1
2(d)(ii) Percentage uncertainty based on an absolute uncertainty in the range 2–3 mm.
If repeat readings have been taken, then the absolute uncertainty can be half the range (but not zero) if the working is
clearly shown.
1
2(d)(iii) Raw value(s) for x2 to nearest 0.1 cm. 1
2(d)(iv) Correct calculation of g with consistent unit. 1

PUBLISHED
May/June 2021
2(e)(i) A Two TS
2 – TV
2 values are not enough to draw a (valid) conclusion (not “not enough for accurate results”, “few
readings”).
B Difficult to maintain single mode of oscillation e.g. spring swings when measuring vertical oscillations/spring bounces
when measuring swinging oscillations/spring swings in more than one plane.
C Spring slides along rod during the oscillation.
D Difficult to judge/determine/decide when an oscillation starts/ends/is complete.
E Large % uncertainty in Tv
or
Tv is small so large uncertainty.
F Difficult to measure x1 or x2 with reason e.g. parallax error
or
difficult to measure x2 due to space at end of ruler.
4
2(e)(ii) A Take more readings and plot a graph or take more readings and compare (not “repeat readings” on its own).
B Method to help maintain single mode of oscillation e.g. restrict sideways motion with tube/use parallel guides.
C Method to attach spring to rod/stop spring sliding on rod e.g. adhesive putty/glue spring to rod/cut notch in rod/use rod
with diameter same as diameter of spring loop/rougher rod.
D Video/record/film with timer in view/frame by frame
or
use fiducial marker at centre of oscillation.
E Use larger masses/use spring with lower spring constant/stiffness.
F Use calipers/travelling microscope/use ruler starting at zero/use blocks with detail.
4

PHYSICS 9702/33
MARK SCHEME
Maximum Mark: 40
Published
Teachers.

PUBLISHED
May/June 2021
marking principles.
descriptors.

PUBLISHED
May/June 2021

PUBLISHED
May/June 2021
your working’.

PUBLISHED
May/June 2021
1(a) Final value of L with unit and in the range 60.0–70.0 cm. 1
1(b) Raw values of I with unit and to the nearest 0.1 mA and final value of I < 1 A. 1
1(c) Six sets of readings of x and I (different values) without help from the Supervisor and showing the correct trend
(I decreases as x increases) scores 4 marks, five sets scores 3 marks, etc.
4
Range: xmin ⩽ 10.0 cm and xmax ⩾ 60.0 cm. 1
Column headings:
The presentation of quantity and unit must conform to accepted scientific convention, e.g. 1/I / A–1 or 1/I (A–1) and x/m.
1
Consistency: All values of x must be given to the nearest mm. 1
All values of 1 / I must be given to the same number of significant figures as, or one greater than, the number of
significant figures in raw I.
1
Calculation: Values of 1 / I are correct. 1

PUBLISHED
May/June 2021
1(d)(i) Axes:
Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions.
1
Plotting of points:
Points must be plotted to an accuracy of half a small square in both x and y directions.
1
Quality:
All points in the table (at least 5) must be plotted on the grid.
Trend of points on graph must be correct.
It must be possible to draw a straight line that is within 2.0 cm (to scale) on the x-axis of all plotted points.
1
1
1(d)(iii) Gradient:
1
y-intercept:
or
1

PUBLISHED
May/June 2021
1(e) Value of P = candidate’s gradient and value of Q =candidate’s intercept.
Values must not be written as fractions.
1
Unit for P is correct (e.g. A–1 m–1 or mA–1 cm–1) and unit for Q is correct (e.g. A–1 or mA–1). 1
1(f) Correct calculation of ρA /ρB using PL/Q + 1. 1

PUBLISHED
May/June 2021
2(a) Final value for d with unit and in the range 28.0–40.0 cm. 1
2(b) Percentage uncertainty based on absolute uncertainty in the range 2–6 mm.
clearly shown.
1
2(c)(i) Measurement of raw b to the nearest mm. Final value with unit and in the range 9.0–11.0 cm. 1
2(c)(ii) Correct calculation of α. 1
2(c)(iii) Justification for the number of significant figures in α linked to s.f. in b and d. 1
2(d) Final value for T with unit and in the range 1.50–2.50 s. 1
At least two measurements of nT where n ⩾ 5. 1
2(e) Second values of b and T. 1
Second value of T < first value of T. 1
2(f)(i) Two values of C calculated correctly. The final values must not be written as fractions. 1
2(f)(ii) Valid comment consistent with calculated values of C, testing against a criterion stated by the candidate. 1
2(g) Value of k correctly calculated from the second value of C and with consistent unit, i.e. N m–1 or kg s–2. 1

PUBLISHED
May/June 2021
2(h)(i) A Two readings are not enough to draw a (valid) conclusion (not “not enough for accurate results”, “few readings”).
B Masses falling off/masses stick to a small surface area/not enough adhesive putty for the masses/adhesive putty not
strong enough to hold masses.
C Difficult to judge when the wooden strip is horizontal/difficult to set wooden strip horizontal
or
difficult to judge or set the spring or string vertical.
D Difficulty measuring d with a reason, e.g. finding/determining the centre of the mass/hole
or
difficulty measuring b with a reason, e.g. finding/determining the centre of the nail/holding the ruler parallel to the
strip/set-up wobbly/holding ruler in mid-air.
E Difficult to judge/determine/decide when an oscillation starts/finishes/is complete.
F Different modes of oscillation/string moves during oscillation
or
strip bends/twists/flexes (during oscillation).
4

PUBLISHED
May/June 2021
2(h)(ii) A Take more readings and plot a graph or take more readings and compare C values (not “repeat readings” on its
own).
B Wider strip/named method for improving the adhesion of the masses, e.g. glue/tape with reference to masses.
C Method of ensuring strip is horizontal, e.g. use a spirit level
or
method to ensure spring/string is vertical, e.g. use a plumb-line.
D Improved method to measure b or d, e.g. add a scale to the strip/mark on the strip/clamp ruler.
E Fiducial marker at the centre of the oscillation
or
video/record/film with timer in view/play back frame by frame.
F Use a thicker/stiffer/laminated strip
or
sand to make rougher/add notch to wooden strip or rod/stick sandpaper to wooden strip or rod.
4

PHYSICS 9702/34
MARK SCHEME
Maximum Mark: 40
Published
Teachers.

PUBLISHED
May/June 2021
marking principles.
descriptors.

PUBLISHED
May/June 2021

PUBLISHED
May/June 2021
your working’.

PUBLISHED
May/June 2021
1(a)(i) Value of C to the nearest mm. 1
1(a)(ii) Value of T with unit and in the range 0.50–1.50 s. 1
At least two measurements of nT where n ⩾ 5. 1
1(b) Six sets of readings of C and T (different values) with correct trend (T increases as C increases) and without help from the
Supervisor scores 4 marks, five sets scores 3 marks etc.
4
Range: Cmin ⩽ 18.0 cm and Cmax ⩾ 35.0 cm. 1
Column headings:
The presentation of quantity and unit must conform to accepted scientific convention e.g. 1/√C / cm–½, 1/T (s–1).
1
Consistency:
All values of raw times must be given to the nearest 0.1 s or all to the nearest 0.01 s.
1
Values of 1 / √C must be given to the same number of significant figures as, or one greater than, the number of significant
figures in C.
1
Calculation: Values of 1 / √C calculated correctly. 1

PUBLISHED
May/June 2021
1(c)(i) Axes:
Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions.
1
Plotting of points:
Points must be plotted to an accuracy of half a small square in both x and y directions.
1
Quality:
Trend of points must be correct.
It must be possible to draw a straight line that is within ± 5.0 × 10–3 cm–½ (± 5.0 × 10–2 m–½) on the 1 / √C axis (normally x-
axis) of all plotted points.
1
1(c)(ii) Line of best fit:
1
1(c)(iii) Gradient:
1
y-intercept:
or
1

PUBLISHED
May/June 2021
1(d) Value of a equal to candidate’s gradient and value of b equal to candidate’s intercept. Values must not be written as
fractions.
1
Units for a and b correct, e.g. cm½ s–1 for a and s–1 for b. 1

PUBLISHED
May/June 2021
2(a)(i) Values of D1 and D2 both to nearest mm. 1
Evidence of repeat readings for D1 and D2. 1
2(a)(ii) Percentage uncertainty based on an absolute uncertainty of 2–5 mm.
clearly shown.
1
2(b) All values of h1 and h2 to nearest 0.1 mm or all to nearest 0.01 mm. 1
Correct calculation of y. 1
2(c)(i) Values of A and B recorded and A < B. 1
2(c)(ii) Correct calculation of F. 1
2(c)(iii) Justification for significant figures in F linked to s.f. in B and A. 1
2(d) Second values of D1, D2, h1 and h2. 1
y smaller for smaller D2. 1
2(e)(i) Two values of k calculated correctly. 1
2(e)(ii) Valid comment relating to the calculated values of k, testing against a criterion specified by the candidate. 1

PUBLISHED
May/June 2021
2(f)(i) A Two readings are not enough to draw a (valid) conclusion (not “not enough for accurate results”, “few readings”).
B Difficult to judge/determine whether rod is horizontal.
C Difficult to measure h with reason e.g. parallax error/wooden block or ring getting in way.
D Large percentage uncertainty in y.
E Difficult to measure A or B with reason e.g. judging centre of slotted mass when measuring B/judging centre of nail for
A or B/parallax error in A or B/difficult to hold ruler steady when measuring A or B. (Allow parallax error linked to h or
A or B only once.)
4
2(f)(ii) A Take more readings and plot a graph or take more readings and compare k values (not “repeat readings” on its own).
B Improved method to determine if rod horizontal e.g. use a spirit level/use set square(s) with description of method.
C Method to reduce error in measuring h e.g. use wider rod/move ring to edge of block/use travelling microscope.
D Method to reduce percentage uncertainty in y e.g. measure change in height at end of rod/use larger mass/increase B.
E Improved method of measuring A or B e.g. clamp ruler/method to locate and mark centre of slotted mass e.g. measure
diameter and halve to find radius.
4

PHYSICS 9702/35
MARK SCHEME
Maximum Mark: 40
Published
Teachers.

9702_s21_ms_all.pdf

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