GCE
Physics A
H156/01: Breadth in physics
Advanced Subsidiary GCE
Mark Scheme for November 2020
Oxford Cambridge and RSA Examinations
GCE
Physics A
H156/01: Breadth in physics
Advanced Subsidiary GCE
Mark Sch
...
GCE
Physics A
H156/01: Breadth in physics
Advanced Subsidiary GCE
Mark Scheme for November 2020
Oxford Cambridge and RSA Examinations
GCE
Physics A
H156/01: Breadth in physics
Advanced Subsidiary GCE
Mark Scheme for November 2020Oxford Cambridge and RSA Examinations
OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide range of
qualifications to meet the needs of candidates of all ages and abilities. OCR qualifications
include AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals,
Functional Skills, Key Skills, Entry Level qualifications, NVQs and vocational qualifications in
areas such as IT, business, languages, teaching/training, administration and secretarial skills.
It is also responsible for developing new specifications to meet national requirements and the
needs of students and teachers. OCR is a not-for-profit organisation; any surplus made is
invested back into the establishment to help towards the development of qualifications and
support, which keep pace with the changing needs of today’s society.
This mark scheme is published as an aid to teachers and students, to indicate the requirements
of the examination. It shows the basis on which marks were awarded by examiners. It does not
indicate the details of the discussions which took place at an examiners’ meeting before marking
commenced.
All examiners are instructed that alternative correct answers and unexpected approaches in
candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills
demonstrated.
Mark schemes should be read in conjunction with the published question papers and the report
on the examination.
© OCR 2020H156/01 Final Mark Scheme November 2020
2
Here are the subject specific instructions for this question paper.
CATEGORISATION OF MARKS
The marking schemes categorise marks on the MACB scheme.
M marks These are method marks upon which A-marks (accuracy marks) later depend. For an M-mark to be scored, the point to which
it refers must be seen in the candidate’s answers. If a candidate fails to score a particular M-mark, then none of the
dependent A-marks can be scored.
A marks These are accuracy or answer marks, which either depend on an M-mark, or allow a C-mark to be scored.
C marks These are compensatory method marks which can be scored 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 it. 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 given.
B marks These are awarded as independent marks, which do not depend on other marks. For a B-mark to be scored, the point to
which it refers must be seen specifically in the candidate’s answers.
SIGNIFICANT FIGURES
If the data given in a question is to 2 sf, then allow an answer to 2 or more significant figures.
If an answer is given to fewer than 2 sf, then penalise once only in the entire paper.
Any exception to this rule will be mentioned in the Guidance.H156/01 Final Mark Scheme November 2020
3
Annotations
Annotation Meaning
Correct response Used to indicate the point at which a mark has been awarded (one tick per mark awarded).
Incorrect response Used to indicate an incorrect answer or a point where a mark is lost.
AE 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.
BOD Benefit of doubt given
Used to indicate a mark awarded where the candidate provides an answer that is not totally satisfactory, but the
examiner feels that sufficient work has been done.
BP Blank page Use BP on additional page(s) to show that there is no additional work provided by the candidates.
CON Contradiction No mark can be awarded if the candidate contradicts himself or herself in the same response.
ECF Error carried forward
Used in numerical answers only, unless specified otherwise in the mark scheme. Answers to later sections of
numerical questions may be awarded up to full credit provided they are consistent with earlier incorrect answers.
Within a question, ECF can be given for AE, TE and POT errors but not for XP.
L1 Level 1 L1 is used to show 2 marks awarded and L1^ is used to show 1 mark awarded.
L2 Level 2 L2 is used to show 4 marks awarded and L2^ is used to show 3 marks awarded.
L3 Level 3 L3 is used to show 6 marks awarded and L3^ is used to show 5 marks awarded.
POT Power of 10 error
This is usually linked to conversion of SI prefixes. Do not allow the mark where the error occurs. Then follow
through the working/calculation giving ECF for subsequent marks if there are no further errors.
SEEN Seen To indicate working/text has been seen by the examiner.
SF Error in number of
significant figures
Where more SFs are given than is justified by the question, do not penalise. Fewer significant figures than
necessary will be considered within the mark scheme. Penalised only once in the paper.
TE Transcription error
This error is when there is incorrect transcription of the correct data from the question, graphical read-off, formulae
booklet or a previous answer. Do not allow the relevant mark and then follow through the working giving ECF for
subsequent marks.
XP Wrong physics or
equation
Used in numerical answers only, unless otherwise specified in the mark scheme. Use of an incorrect equation is
wrong physics even if it happens to lead to the correct answer.
^ Omission Used to indicate where more is needed for a mark to be awarded (what is written is not wrong but not enough).H156/01 Final Mark Scheme November 2020
4
Abbreviations, annotations and conventions used in the detailed Mark Scheme (to include abbreviations and subject-specific conventions).
Annotation Meaning
/ alternative and acceptable answers for the same marking point
Reject Answers which are not worthy of credit
Not Answers which are not worthy of credit
Ignore Statements which are irrelevant
Allow Answers that can be accepted
( ) Words which are not essential to gain credit
___
Underlined words must be present in answer to score a mark
ECF Error carried forward
AW Alternative wording
ORA Or reverse argument
SECTION AH156/01 Final Mark Scheme November 2020
5
Question Answer Marks Guidance
1 A 1
2 A 1
3 C 1
4 D 1
5 A 1
6 C 1
7 C 1
8 A 1
9 C 1
10 B 1
11 D 1
12 A 1
13 A 1
14 B 1
15 C 1
16 B 1
17 D 1
18 A 1
19 C 1
20 D 1
Total 20H156/01 Final Mark Scheme November 2020
6
SECTION B
General rule: For substitution into an equation, allow any subject – unless stated otherwise in the guidance
Question Answer Marks Guidance
21 (a) momentum
kinetic energy / total energy
B1
B1 Allow energy / mass
(b) (Motion / speed / force / acceleration of person or
skateboard is to the) left / opposite direction to ball /
‘backwards’
momentum is conserved / momentum of person =
momentum of ball (but in opposite direction)
(total) momentum is zero (at start or at the end or during
the throwing of the ball) / speed of person < speed of ball
B1
B1
B1
Allow ‘principle of conservation of momentum’
Allow ‘equal and opposite forces (acting on ball and person
for the same time interval)’
Allow ‘different speed’
Allow velocity
Total 5
Question Answer Marks Guidance
22 (a) v → m s-1 or v2 → m2 s-2
Clear algebra leading to base unit = kg m-1
M1
A1
(b) 0.12
1.20
(× 100) or 0.24
4.00
(× 100) or (k =) 2.78 (kg m-1)
[2 × 0.1 + 0.06] or 0.26 or 26 %
absolute uncertainty = 0.72 (kg m-1)
C1
C1
A1
Allow (kmax =) 4.24
1.082 and (kmin =) 13.32 .762 or 3.635 and 2.158
Allow (range =) 1.48
Note: The answer must be given to 2 SF – as required by
the question
Ignore any value given for k on the answer line
Total 5H156/01 Final Mark Scheme November 2020
7
Question Answer Marks Guidance
23 (a) (i) Straight line drawn from the bottom of the 9.0 m s-1 vector
to the end of the 4.2 m s-1 vector B1
Ignore incorrect / omitted direction of resultant vector
Ignore any other additional lines drawn
(ii) v2 = 9.02 + 4.22 – 2 × 9.0 × 4.2 × cos50°
v = 7.1 (m s-1)
OR
length of resultant vector line measured and some
calculations
v = 7.1 (m s-1)
C1
A1
C1
A1
Allow other correct variants of this method
Note answer to 3 SF is 7.07
Allow length of resultant vector in the range 5.4 – 5.6 cm
Allow ± 0.20 (m s-1)
(b) (i) (stress =) 7.5
8.2×10−7 or 9.15 × 106 (Pa)
(strain =) 7.5
8.2×10−7 × 2.0×1011 or 4.57 × 10-5
x = 2.8 × 10-5 (m)
OR
� = ��
��
2.0 × 1011 = 7.5 × 0.62
8.2 × 10−7 × �
x = 2.8 × 10-5 (m)
C1
C1
A1
C1
C1
A1
Allow full credit for alternative methods
Note answer is 2.84 × 10-5 to 3 SF
Note answer is 2.84 × 10-5 to 3 SF
Special case: 1 mark for 2.8 × 10-4 (m) or 2.9 × 10-6 (m);
7.5g or 7.5g-1 (g = 9.81) used instead of 7.5
(ii) acceleration at Y / deceleration at Z
At Y (tension is) greater / (T ) > 7.5 (N)
At Z (tension is) less / (T) < 7.5 (N)
B1
B1
B1
Allow increasing velocity / increasing speed at Y
Allow decreasing velocity / decreasing speed / negative
acceleration at Z / slowing down
Ignore ‘downward acceleration’ at Z
Ignore drag throughout
Allow (T) > weight
Allow (T) < weight
Total 9H156/01 Final Mark Scheme November 2020
8
Question Answer Marks Guidance
24 (a) (i) Systematic error / meter not zeroed (AW) B1 Allow resistance due to crocodile clips / resistance of
connecting wires / internal resistance (of cell in ohmmeter)
/ resistance of ohmmeter
(ii) Use a vernier calliper / micrometer to measure diameter
of pencil lead (and hence determine A)
ρ = gradient of line × A (Any subject)
Any one from:
• A = π�2
4
• Measure the diameter in several positions (and
average)
• Use a large ‘triangle’ to determine the gradient
B1
B1
B1
Allow vernier / calliper
Allow use of ‘slope’ for gradient
Allow A = πr2 and d = 2r
(b) (i) (1200
300
)
4.0 B1 Allow 1 SF
(ii) 180 = � ×25
6.7 × 10−8
ρ = 4.8 × 10-7 (Ω m)
C1
A1 Note answer is 4.82 × 10-7 to 3 SF
Total 7H156/01 Final Mark Scheme November 2020
9
Question Answer Marks Guidance
25 (a) Current less
Cell has internal resistance or greater (total) resistance or
p.d. across internal resistor or p.d. across resistor/10.0 (Ω)
B1
B1 Allow ‘lost volts’ / power lost in cell
Ignore wires have resistance
(b) (VA =) 6.0 (V) or (RA =) 30 (Ω)
For parallel lamps, any one from:
(V|| =) 2.0 (V) or (I =) 0.10 (A) or (RL =) 20 (Ω)
or (R|| =) 10 (Ω)
resistance = 40 (Ω)
C1
C1
A1
Not R|| = 15 (Ω); this is XP
Total 5
Question Answer Marks Guidance
26 (a) constant phase (difference of 90°) B1 Ignore incorrect value
Ignore same wavelength / frequency / period
(b) (period =) 4.0 (ms)
(f = 0.004-1)
f = 250 (Hz)
C1
A1 Allow 1 mark for 0.25; k omitted
(c)
(intensity =) �24 10�2(I0)
intensity = 5.8 (I0)
C1
A1 Not 144 25 �0
Allow 1 mark for 4.84; misread graph and used (22
10
)2
(d) resultant displacement = 10 (µm) B1 Allow ± 1.5; Ignore sign
Total 6H156/01 Final Mark Scheme November 2020
10
Question Answer Marks Guidance
27 (a) (At the point where two or more waves meet the) resultant
displacement is equal to the sum of the individual
displacements (of the waves)
B1
Allow sum / net / total for resultant
Ignore vector sum
Not amplitude
(b) Maxima is when constructive (interference) occurs / phase
difference is zero / path difference = nλ
Minima is when destructive (interference) occurs / phase
difference is 180(°) or π( rad) / path difference = (n + ½)λ at
minima
B1
B1
Allow ‘completely in phase’ for phase difference is zero
Allow ‘antiphase’/ ‘completely out of phase’ for phase
difference is 180(°)
Allow 1 mark for ‘constructive and destructive
(interference)’, without any link to the maxima and minima
(c) (x =) 200 × 18 or (x =) 3600 (m)
(λ =) 120 ×3600
2400
λ = 180 (m)
C1
C1
A1
Not v = fλ ; 18 = 1
200
× � or λ = 3600 (m)
Allow 3600 m from v = fλ when used as x here
Note using x = 1800 m is XP (this gives 90 m)
Total 6H156/01 Final Mark Scheme November 2020
11
Question Answer Marks Guidance
28 (a) Photon mentioned / one-to-one interaction (between
electron and photon)
(Maximum KE of electrons decreases as wavelength
increases because) KE(max) = ℎ�
� − � (Any subject)
(When λ < λ0) energy (of photon) > work function /
f > threshold frequency and electrons emitted / KE(max) ≠ 0
or
(When λ = λ0) energy (of photon) = work function /
f = threshold frequency and electrons just emitted / not
emitted / KE(max) = 0
or
(When λ > λ0) energy (of photon) < work function / f <
threshold frequency and electrons not emitted / KE(max) = 0
B1
B1
B1
Not KE(max) = hf - φ by itself, but allow with c = fλ
Allow ℎ�
� or hf for ‘energy of photon’ and φ for ‘work
function’ for this B1 mark
Not f0 for threshold frequency
Allow λ0 / threshold wavelength is the maximum
wavelength for electrons to be emitted
Allow threshold frequency is the minimum frequency for
electron(s) to be emitted
Allow work function is the minimum energy for electron(s)
to be emitted
(b) (i) E = 6.63 × 10−34 × 3.0 × 108
490 × 10−9
energy = 4.1 × 10-19 (J)
C1
A1 Note answer to 3 SF is 4.06 × 10-19
(ii) (number of photons =) 0.230
4.06 × 10−19
number of photons = 5.7 × 1017
C1
A1
Possible ECF from (b)(i)
Note answer is 5.6 × 1017 when 4.1 × 10-19 is used
Total 7OCR (Oxford Cambridge and RSA Examinations)
The Triangle Building
Shaftesbury Road
Cambridge
CB2 8EA
[Show More]
.png)
