WJEC 2016 Online Exam Review
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WJEC 2016 Online Exam Review GCSE PHYSICS 3 Foundation 4503-01 All Candidates' performance across questions Question Title N Mean S D Max Mark F F Attempt % 1 1178 6.4 1.6 9 70.9 99.9 2 1179 3.4 1.4 7 48.6 100 3 1172 3.5 1.1 5 70.1 99.4 4 1176 3.5 1.1 5 69.1 99.8 5 1176 2 1 4 50.5 99.8 6 1171 3.2 1.6 6 52.9 99.3 7 1178 7.6 1.7 14 54.2 99.9 8 1166 2.7 2 10 26.5 98.9 70.9 48.6 70.1 69.1 50.5 52.9 54.2 26.5 0 10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 Facility Factor % Question GCSE PHYSICS 3 Foundation 4503-01
Transcript of WJEC 2016 Online Exam Review
WJEC 2016 Online Exam Review
GCSE PHYSICS 3 Foundation 4503-01
All Candidates' performance across questions
Question Title N Mean S D Max Mark F F Attempt %1 1178 6.4 1.6 9 70.9 99.92 1179 3.4 1.4 7 48.6 1003 1172 3.5 1.1 5 70.1 99.44 1176 3.5 1.1 5 69.1 99.85 1176 2 1 4 50.5 99.86 1171 3.2 1.6 6 52.9 99.37 1178 7.6 1.7 14 54.2 99.98 1166 2.7 2 10 26.5 98.9
70.9
48.6
70.1
69.1
50.5
52.9
54.2
26.5
0 10 20 30 40 50 60 70 80 90 100
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2
3
4
5
6
7
8
Facility Factor %
Que
stio
n
GCSE PHYSICS 3 Foundation 4503-01
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Usually the question number
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The number of candidates attempting that question
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The mean score is calculated by adding up the individual candidate scores and dividing by the total number of candidates. If all candidates perform well on a particular item, the mean score will be close to the maximum mark. Conversely, if candidates as a whole perform poorly on the item there will be a large difference between the mean score and the maximum mark. A simple comparison of the mean marks will identify those items that contribute significantly to the overall performance of the candidates. However, because the maximum mark may not be the same for each item, a comparison of the means provides only a partial indication of candidate performance. Equal means does not necessarily imply equal performance. For questions with different maximum marks, the facility factor should be used to compare performance.
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The standard deviation measures the spread of the data about the mean score. The larger the standard deviation is, the more dispersed (or less consistent) the candidate performances are for that item. An increase in the standard deviation points to increased diversity amongst candidates, or to a more discriminating paper, as the marks are more dispersed about the centre. By contrast a decrease in the standard deviation would suggest more homogeneity amongst the candidates, or a less discriminating paper, as candidate marks are more clustered about the centre.
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This is the maximum mark for a particular question
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The facility factor for an item expresses the mean mark as a percentage of the maximum mark (Max. Mark) and is a measure of the accessibility of the item. If the mean mark obtained by candidates is close to the maximum mark, the facility factor will be close to 100 per cent and the item would be considered to be very accessible. If on the other hand the mean mark is low when compared with the maximum score, the facility factor will be small and the item considered less accessible to candidates.
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For each item the table shows the number (N) and percentage of candidates who attempted the question. When comparing items on this measure it is important to consider the order in which the items appear on the paper. If the total time available for a paper is limited, there is the possibility of some candidates running out of time. This may result in those items towards the end of the paper having a deflated figure on this measure. If the time allocated to the paper is not considered to be a significant factor, a low percentage may indicate issues of accessibility. Where candidates have a choice of question the statistics evidence candidate preferences, but will also be influenced by the teaching policy within centres.
(4503-01) Turn over.© WJEC CBAC Ltd.
15Examiner
only8. (a) The diagrams below are drawings made by a student investigating how light rays pass
through a semi-circular glass block.
(i) Label the critical angle (c) on the appropriate diagram above. [1]
(ii) Describe and explain the observations shown in the drawings as fully as you can.[6 QWC]
You should:• describe what happens to the light ray in each of the diagrams above;• explain why the light ray follows the path shown in each diagram.
TURN OVER FOR THE LAST PART OF THE QUESTION
Diagram A Diagram B Diagram C
(b) Complete the diagram below to show how the light entering at A travels along the optical fibre. [3]
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© WJEC CBAC Ltd.
END OF PAPER
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Question Number
FT HT Sub-section Mark Answer Accept Neutral answer Do not accept
5 (a) 2 Temperature = 0 [K] - 1 mark Pressure = 12 [N/cm2] – 1 mark
(b) 2 The molecules travel faster / have more energy (1) More frequent / harder collisions / collide more often [with the container] (1)
More frequent / harder collisions with each other
They collide more / there is more energy / increased number of collisions
Total 4
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The candidate does not know the effect that a temperature increase has on molecular motion and invents the term "pressure molecules". No marks were awarded for the answer.
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The sequence relating temperature in Kelvins to the Celsius temperature has not been identified from the data in the table, neither is the conversion known. The relationship between increasing Kelvin temperature and pressure has not been applied to obtain the missing pressure value.
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The molecules do not create kinetic energy through collisions. No mark was awarded for this answer.
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The Kelvin equivalent of -273 Celsius has been correctly applied in the table. The candidate has identified the relationship between pressure and Kelvin temperature values and has applied it correctly. 2 marks were awarded.
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One mark was awarded for the increase in speed of the molecules associated with the increase in temperature of the gas.
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Two marks were given for the correct answers to both missing cells in the table.
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5. A fixed mass of gas is kept under conditions of constant volume. The table shows how thepressure of this gas changes with temperature when it is heated.
© WJEC CBAC Ltd.
Temperature(°C)
Temperature (K)
Pressure(N/cm2)
–273. . . . . . . . . . . . . . . . . . . . . .
0
–173 100 4
–123 150 6
–73 200 8
+27 300. . . . . . . . . . . . . . . . . . . . . .
+77 350 14
+127 400 16
(a) Complete the table above. [2]
(b) Explain in terms of molecules why the pressure increases as the temperature increases.[2]
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Question Number
FT HT Sub-section Mark Answer Accept Neutral answer
Do not accept
6 (a) 1 The speeds are bigger [between 2 and 4 seconds] The speed is bigger / moving faster / it is accelerating
(b) (i) 2 a(40 -10)
(4 -1)using any matching speeds and times (1)
= 10 [m/s2] (1-ans)
Errors in expression e.g.
(40 – 10) 30
=3
= 10 [m/s2] award 2 marks
Confusion between u and v
values
(ii) 2 12(20+40)x 2 (1-sub)
= 60 [m] (1-ans)
(c) 1 Air resistance has a bigger effect [on the feather than on the stone.]
Because the feather is lighter / smaller mass
More air resistance acts on the feather / smaller terminal velocity / feather is less dense / less momentum / reference to surface area
Total 6
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The air resistance has a bigger effect on the stone because it is lighter than the stone. The mark was awarded.
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The incorrect time interval has been used in the equation so no marks were awarded.
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The candidate has offered two optional answers but the rule is that examiners make a decision based on the answer on the final answer line. The candidate has opted for the correct answer and gets two marks.
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Despite the wooly wording in the answer, the fact that there is an acceleration gets the mark - just.
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Air resistance has a bigger effect on the feather because it is smaller in mass. Therefore one mark was awarded.
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The values of 90 and 9 that have been substituted into the equation are incorrect. No mark was awarded.
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Any matching pair of speeds and times could have been used. No mark was awarded for this answer. The substitution of data into the equation is incorrect.
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A mark was awarded for the candidate identifying that there is an increase in speed (as time progresses).
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The air resistance has a bigger effect on the feather because it is lighter. The mark was awarded. The candidate gained full marks on this question.
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Correct substitution and answer again gets both marks.
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Correct substitution and the correct answer gets both marks.
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The answer "moving quicker" gets that mark.
(4503-01) Turn over.
11Examiner
only6. A small stone falls through the air. The table below shows how the velocity of the stone changes
in the first 4 seconds.
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Time (s) Speed (m/s)
0 0
1 10
2 20
3 30
4 40
(a) State why the distance travelled between 2 seconds and 4 seconds is bigger than for the first two seconds. [1]
(b) (i) Use information from the table and the equation:
to calculate the acceleration. [2]
acceleration = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . m/s2
(ii) Use information from the table and the equation:
to calculate the distance that the stone fell between 2 s and 4 s. [2]
distance = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . m
(c) If a feather were dropped instead, its velocity after 4 s would be less than that of the stone. Give a reason for the difference. [1]
a v ut= –
x u v t= +( )12
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Question Number
FT HT Sub-section Mark Answer Accept Neutral answer Do not accept
8 2 (a) (i) 1 c shown in correct position on middle drawing
i.e. drawn between the normal and the ray Labelling using the words critical angle or 42o
(ii) 6 Indicative content: When the angle of incidence is less than the critical angle the light is refracted away from the normal as it passes into the air (A). This happens because light travels faster in air than in glass or the light is travelling into an optically less dense medium. When the angle of incidence is equal to the critical angle the light just escapes from the glass and travels along the glass-air boundary (B). If the angle of incidence is greater than the critical angle then total internal reflection occurs (C). TIR occurs when light is travelling from a more dense towards a less dense medium at an angle bigger than the critical angle.
5-6 marks The candidate constructs an articulate, integrated account correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar.
3-4 marks The candidate constructs an account correctly linking some relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar.
1-2 marks The candidate makes some relevant points, such as those in the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar.
0 marks The candidate does not make any attempt or give a relevant answer worthy of credit.
(b) 3 Correct refraction at A i.e. refracted towards the normal (1) TIR shown - at the glass sides with straight lines (1) reflections show i = r by eye (1)
Total 10
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Two marks were awarded. The terminology is correct for the description of refraction in the first diagram. For the second diagram the answer suggests that the critical angle is the angle of emergence, not the angle of incidence in the glass but in diagram C the term "totally internally reflects" is correctly used to identify the optical effect.
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Correct diagram for the critical angle but not in the correct position. No mark was awarded.
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Two marks were awarded for the completed diagram. The only thing wrong was the lack of refraction of the ray on entry to the glass fibre. The internal reflections are sharp and the repeat distance between reflections (as an indication of repeat angles) is good.
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The angle is correctly labelled on the correct diagram. One mark
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The refraction is incorrect, the rays gently bend instead of being abruptly totally internally reflected and the angles of incidence and reflection (if there are any) are not sufficiently carefully repeated. No mark was awarded. Three marks were awarded in total for this question.
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Two marks were awarded for the correct refraction argument in the first diagram, with a reason for the refraction being correct. There was little else that was correct.
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The critical angle is correctly labelled. One mark.
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One mark was given for this part of the question. The internal reflections are sharp and occur clearly at the glass-air boundaries but the initial refraction is incorrect and the repeat angles are not drawn carefully enough (as shown by the reflection repeat distances). Six marks were awarded for the question as a whole.
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In the description of digram A, the statement that the critical angle is less than the angle of incidence is wrong but otherwise there is plenty to be celebrated in the answer. The second diagram is described correctly as is the third diagram. Four marks were awarded.
