Physics 9702/52 October/November 2025: question paper and mark scheme
Cambridge AS & A Level Physics (9702), Paper 5 Planning, Analysis and Evaluation, October/November 2025. Read both free below, or download them. Done the paper? Get it marked by AI against this mark scheme.
Fig. 1.1 shows a model wind turbine with blades, each of length L, placed in moving air.
L
moving air
blade
terminals turbine bench
Fig. 1.1
The area of the circle swept by the blades of the turbine is A.
The output of the turbine has two terminals. The turbine is connected to a resistor of resistance R.
At a speed v of the moving air, the current in the resistor is I.
The atmospheric pressure is P and the thermodynamic temperature of the air is T.
It is suggested that I is related to v by the relationship
I 2R APv 3
=
Q 2T where Q is a constant.
Plan a laboratory experiment to test the relationship between I and v.
Draw a diagram showing the arrangement of your equipment.
Explain how the results could be used to determine a value for Q.
In your plan you should include:
• the procedure to be followed
• the measurements to be taken
• the control of variables
• the analysis of the data
• any safety precautions to be taken.
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3
Diagram
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…… [15]
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5
Mark scheme
1 Defining the problem
vary v and measure I or v is the independent variable and I is the dependent variable 1
keep A and R constant 1
Methods of data collection
labelled diagram of workable experiment including: 1
• fan positioned in line with the turbine so that blades of both fan and turbine overlap
• fan on bench
• fan labelled and one other label from bench, turbine, blade(s) (of turbine), terminals, L
workable circuit diagram showing resistor connected to an ammeter in series with the terminals of the turbine using correct 1
circuit symbols
method to vary v, e.g. change speed of fan / change distance between fan and blades / vary current in or p.d. across fan 1
method to determine temperature T, e.g. use a thermometer 1
Method of Analysis
plot a graph of I2 against v3 or equivalent (e.g. lg I against lg v or 2 ln I against ln v) 1
relationship valid if a straight line is produced passing through the origin 1
(For lg I against lg v: relationship valid if a straight line with gradient = 1.5 is produced)
2TR × gradient 1
Q=
AP
2TR × 102×y -intercept
(For lg I against lg v: Q = )
AP
1 Additional detail including safety considerations 6
D1 precaution with reason linked to (moving) fan blades / turbine blades, e.g. keep away from the fan to avoid (moving)
blades or use a screen around the fan / turbine to avoid (moving) blades
or
precaution with reason linked to prevent air / dust particles in eye, e.g. use goggles to avoid air stream (into eye)
D2 clamp turbine / fan to bench
D3 keep P and T constant
D4 T = t + 273
D5 method to determine A: use a rule(r) / calipers to measure L and A = πL2
D6 repeat measurements of L in different positions / different blades and average
D7 method to measure v, e.g. use an anemometer or air speed meter
or
method to measure P, e.g. use a manometer or barometer or pressure gauge
D8 wait for steady / constant air flow / movement of blades / current
D9 method to determine R, e.g.:
separate circuit showing ohmmeter connected to R only
or
terminals of turbine connected correctly to resistor and ammeter and voltmeter across resistor and R = V / I
or
separate workable circuit with power supply resistor, ammeter and voltmeter across R and R = V / I
D10 method to check temperature / pressure is constant, e.g. measure temperature / pressure several times / before and
after
A student observes the orbits of some of the moons around the planet Saturn, as shown in Fig. 2.1.
Tethys
Rhea
Mimas
Saturn
Pandora
Enceladus
Dione
Fig. 2.1 (not to scale)
For the moon Pandora, the period of the orbit and the mean distance from the centre of Saturn are determined.
The measurements of period T and mean distance r are repeated for other moons.
It is suggested that T and r are related by the equation
2πr n
T= k where n and k are constants.
(a) A graph is plotted of lg T on the y‑axis against lg r on the x‑axis.
Determine expressions for the gradient and y‑intercept.
gradient = ……
y‑intercept = ……
[1]
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6
(b) Values of r and T are given for different moons in Table 2.1.
Table 2.1
moon r / 108 m T / 103 s lg (r / 108 m) lg (T / 103 s)
Pandora 1.42 52 ± 5
Mimas 1.86 81 ± 5
Enceladus 2.38 120 ± 10
Tethys 2.95 170 ± 10
Dione 3.77 240 ± 20
Rhea 5.28 390 ± 30
Calculate and record values of lg (r / 108 m) and lg (T / 103 s) in Table 2.1. Include the absolute uncertainties in lg (T / 103 s). [2]
(c) (i) Plot a graph of lg (T / 103 s) against lg (r / 108 m). Include error bars for lg (T / 103 s). [2]
(ii) Draw the straight line of best fit and a worst acceptable straight line on your graph. Label both lines. [2]
(iii) Determine the gradient of the line of best fit. Include the absolute uncertainty in your answer.
gradient = …… [2]
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7
2.7
2.6
2.5
lg (T / 103 s)
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
lg (r / 108 m)
* 0000800000008 * DFD
8
(iv) Determine the y‑intercept of the line of best fit. Include the absolute uncertainty in your answer.
y‑intercept = …… [2]
(d) Using your answers to (a), (c)(iii) and (c)(iv), determine the values of n and k.
Include the absolute uncertainties in n and k. You need not be concerned with units.
n = ……
k = ……
[3]
(e) Titan is another moon of Saturn. The orbit of Titan has a period of 1.38 × 106 s.
Determine the value of r for Titan.
r = …… m [1]
[Total: 15]
To avoid the issue of disclosure of answer‑related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge
Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series.
Mark scheme
2(a) gradient = n 1
2π
y-intercept = lg
k
2(b) 1
lg (r / 108 m) lg (T / 103 s)
0.152 or 0.1523 (1.72 or 1.716) ± 0.04
0.270 or 0.2695 (1.91 or 1.908) ± 0.03
0.377 or 0.3766 (2.08 or 2.079 or 2.0792) ± 0.04
0.470 or 0.4698 (2.23 or 2.230 or 2.2304) ± 0.03
0.576 or 0.5763 (2.38 or 2.380 or 2.3802) ± 0.04
0.723 or 0.7226 (2.59 or 2.591 or 2.5911) ± 0.03
Values of lg (r / 108 m) and lg (T / 103 s) correct as shown above.
Uncertainties in lg (T / 103 s) correct as shown above. 1
2(c)(i) Six points from (b) plotted correctly. 1
Must be within half a small square. Diameter of points must be less than half a small square.
Error bars in lg (T / 103 s) plotted correctly. 1
All error bars must be plotted. Total length of bar must be accurate to less than half a small square and symmetrical.
2(c)(ii) Straight line of best fit drawn. 1
Thickness of the line must be less than half a small square.
Do not accept line from top point to bottom point.
Line must pass between (0.19, 1.80) and (0.21, 1.80) and between (0.645, 2.50) and (0.66, 2.50).
Worst acceptable line drawn (steepest or shallowest possible line that passes through all the error bars). 1
Thickness of the line must be less than half a small square.
All error bars must be plotted.
2(c)(iii) Gradient determined with clear substitution of data points into Δy / Δx. 1
Distance between data points must be greater than half the length of the drawn line.
Gradient determined of worst acceptable line with clear substitution of data points into Δy / Δx. 1
uncertainty = (gradient of line of best fit – gradient of worst acceptable line)
or
uncertainty = ½ (steepest worst line gradient – shallowest worst line gradient)
2(c)(iv) y-intercept determined by substitution of correct point with consistent powers of ten into y = mx + c. 1
y-intercept of worst acceptable line determined by substitution into y = mx + c. 1
uncertainty = y-intercept of line of best fit – y-intercept of worst acceptable line
or
uncertainty = ½ (steepest worst line y-intercept – shallowest worst line y-intercept)
Do not accept ECF from false origin method.
2(d) Value of n determined using gradient and n and k given to 2 or 3 significant figures. 1
n = gradient = (c)(iii)
Value of k determined using y-intercept. 1
Correct method must be seen.
2π 2π
k= y -intercept
=
10 10(c)(iv)
Absolute uncertainties in n and k determined. 1
Absolute uncertainty in n = absolute uncertainty in gradient
and
2π 2π
Δk = y -intercept
− WAL y -intercept
10 10
Correct method must be seen.
2(e) r determined to a minimum of 2 significant figures from (c)(iii) and (c)(iv) or (d) with correct substitution and correct power 1
of ten.
lg1380 − y -intercept
r = 10 gradient
× 108
or
k × 1380
r =n × 108
2π
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On this page, free: the mark scheme for AS & A Level Physics 9702/52, October/November 2025 (9702_w25_ms_52), and the question paper (9702_w25_qp_52), to read or download, with each question's marking points written out underneath.
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Physics 9702/52 for October/November 2025 is out of 30 marks, with 1 hour 15 minutes to answer it.
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