Cambridge AS & A Level Physics 9702/52 is the May/June 2026 Paper 5 (Planning, Analysis and Evaluation), variant 2. It lasts 1 hour 15 minutes, is worth 30 marks and is the written practical paper sat by every full A Level candidate. It had two compulsory questions worth 15 marks each: a plan for an experiment with a capacitor and a reed switch, and an analysis of oscillation data with error bars and uncertainties. This guide goes through both and shows what the official mark scheme gave marks for. The paper and its mark scheme are free on the Tutopiya Learning Portal.

For an overview of all five 9702 papers from this series, see A Level Physics 9702 May/June 2026 past papers: what came up and how it was marked.

9702/52 at a glance

Question	Topic	Skills tested	Marks
1	Plan: a parallel-plate capacitor charged and discharged by a reed switch; how the mean current I depends on the plate separation h	Defining the problem, data collection, analysis, additional detail including safety	15
2	Analysis: a rod hung from two parallel strings oscillating about its centre; how the period T depends on the string separation L	Gradient expression, table with uncertainties, error bars, best fit and worst acceptable lines, a constant with its unit and percentage uncertainty	15
	Total		30

Question-by-question walkthrough

Question 1: planning the capacitor experiment (15 marks)

The set-up. A capacitor made of two circular metal plates in air (each of area A, separated by h) was connected to a reed switch, a d.c. supply of e.m.f. E and a resistor. An alternating current at terminals F and G made the switch vibrate at frequency f, so the capacitor charged from the supply for half of each cycle and discharged through the resistor for the other half. The suggested relationship was KA/h = I/(fE), where I is the mean current in the resistor and K is a constant. You had to plan how to test it and find K.

The mark scheme splits the 15 marks into four sections.

Defining the problem (2 marks)

• Vary h and measure I (or name h as the independent variable and I as the dependent one).
• Keep f constant.

Methods of data collection (4 marks)

• A labelled diagram of a workable circuit, with the reed switch and capacitor connected correctly, an ammeter for I and a voltmeter for E. An oscilloscope, or finding I from the p.d. across the resistor with I = V/R, was also accepted.
• A signal generator or a.c. supply connected to terminals F and G.
• The two circular plates shown supported, vertically or horizontally, for example from stands or on the bench, with spacers allowed for the horizontal version.
• A method for measuring h, for example with calipers. A micrometer was accepted only with detail of measuring the total thickness and subtracting the plates. A rule was not accepted.

Method of analysis (3 marks)

• Plot I against 1/h (or an equivalent, such as lg I against lg h).
• The relationship is valid if the graph is a straight line through the origin (or, for the log graph, a straight line with gradient −1).
• K = gradient ÷ (AfE) for I against 1/h, or K = 10^(y-intercept) ÷ (AfE) for the log graph. Your stated analysis had to match the graph you drew.

Additional detail (6 marks from ten points, D1 to D10)

Point	What scored
D1	A safety precaution: clamp the stands so the plates can’t fall, avoid touching a hot resistor, or switch off before adjusting the plates
D2	Keep A and E constant
D3	Measure the plate diameter d with calipers or a rule and use A = πd²/4 (not a micrometer)
D4	Use an oscilloscope to find f (or read it from the signal generator)
D5	Find f from the oscilloscope: the period from the number of divisions in one cycle × the time-base, then f = 1/T
D6	Further detail on the oscilloscope, such as adjusting the time-base or timing n cycles and dividing by n
D7	Insulate the plates’ supports or the bench
D8	Use large plates (large A), or a large E or f, to increase I and reduce its percentage uncertainty
D9	Measure h at several positions between the plates and take the mean
D10	A described method to keep the plates parallel and aligned, such as equal spacers, a set square, a plumb line or a spirit level

Watch for: the defining-the-problem marks could be found anywhere in your answer, but saying h or I is kept constant lost them. D10 needed an explanation, not just “keep the plates parallel”.

Question 2: the rod on two strings (15 marks)

A rod of mass M hangs from a bar by two parallel strings a distance L apart. The rod is twisted and released, and the time t for 10 oscillations is measured for six values of L. The suggested relationship is T = (2π/L)√(αD/Mg), where D is the distance from the bar to the rod and α is a constant.

• Gradient of T² against 1/L² (1 mark): squaring gives T² = (4π²αD/Mg) × (1/L²), so the gradient is 4π²αD/Mg.
• Completing the table (2 marks): one mark for the values of 1/L² and T², one for the uncertainties. The period is T = t/10, so the uncertainty in each t of ±0.2 s becomes ±0.02 s in T. The uncertainty in T² is 2 × (ΔT/T) × T², from ±0.06 (or ±0.07) s² for the longest period down to ±0.03 s² for the shortest.

L / cm	1/L² / m⁻²	T / s	T² / s²
27.4	13.3	1.58 ± 0.02	2.50
30.4	10.8	1.45 ± 0.02	2.10
34.8	8.26	1.26 ± 0.02	1.59
40.8	6.01	1.08 ± 0.02	1.17
48.4	4.27	0.92 ± 0.02	0.85
55.2	3.28	0.80 ± 0.02	0.64

• Plotting with error bars (2 marks): all six points within half a small square (1), and symmetrical T² error bars of the right total length (1). Examiners checked the second and fifth points from the left.
• Best fit and worst acceptable lines (2 marks): a thin straight line of best fit, not simply joined from the top point to the bottom one (1), and a worst acceptable line, the steepest or shallowest line that still passes through every error bar (1).
• Gradient with its uncertainty (2 marks): the gradient from two points on the line far enough apart (expected roughly 0.14 to 0.24 s² m², with Δx of at least 7) (1), and the uncertainty as the difference between the best-fit and worst-line gradients, or half the difference between the steepest and shallowest lines (1).
• Mean D (1 mark): the four readings average to 0.825 m and half the range is 0.004 m, so D = (0.825 ± 0.004) m.
• The constant α (2 marks): α = Mg × gradient ÷ (4π²D), with M = (97 ± 2) g, given to 2 or 3 significant figures (1), and with the unit kg m² (or g m²) and the right power of ten (1). The expected value is about 5.5 × 10⁻³ kg m².
• Percentage uncertainty in α (1 mark): add the percentage uncertainties: (2/97 + Δgradient/gradient + ΔD/D) × 100, or use maximum and minimum values. The answer had to be more than 2%.
• L for a period of (2.20 ± 0.02) s (2 marks): L = √gradient ÷ T, about 0.20 m to at least 2 significant figures (1), and its absolute uncertainty from ½(Δgradient/gradient) + 0.02/2.20, multiplied by L, or from maximum and minimum values (1).

Where the marks are on 9702/52

Skill	Marks	Where
Planning: defining the problem and data collection	6	Question 1
Planning: method of analysis	3	Question 1
Planning: additional detail and safety	6	Question 1
Rearranging the equation for a straight-line graph	1	2(a)
Processing data and uncertainties in a table	2	2(b)
Graph: plotting, error bars and lines	4	2(c)(i)–(ii)
Gradient and its uncertainty	2	2(c)(iii)
Mean, constant, unit and percentage uncertainty	4	2(d)–(e)
Using the result to predict a value with uncertainty	2	2(f)
Total	30

• The plan is half the paper, and 6 of its 15 marks come from extra detail. A plan that only covers the basics can’t score more than 9.
• Uncertainty runs through almost every part of Question 2, from the error bars to the final value of L. Learn the rules for combining percentage uncertainties.

How to self-mark 9702/52 with the mark scheme

1. Mark the plan in its four sections. Tick defining the problem (2), data collection (4) and analysis (3) first, then go through D1 to D10 and stop at 6.
2. Check your diagram on its own. It must show a workable circuit, the a.c. supply at F and G, and supported plates. Some D points, such as insulation (D7), can be credited from the diagram.
3. Make sure your analysis matches your graph. If you said you would plot I against 1/h, your K expression must use that gradient.
4. Check the table against the values above, allowing either 3 or 4 significant figures in 1/L² and T², then check your uncertainties.
5. Check two points on your graph. Re-plot the second and fifth from the left and their error bars to half a small square.
6. Check your worst acceptable line passes through every error bar, and that the read-offs for each gradient are on the line you used.
7. Allow ecf in Question 2. If your gradient was wrong, your α, its uncertainty and L can still score if you used it correctly.

Sit 9702/52 as a timed mock

The paper allows 75 minutes for 30 marks, about two and a half minutes per mark. A workable plan:

Block	Marks	Time
Q1: read, list variables and draw the diagram	6	12 minutes
Q1: write the procedure, analysis and extra detail	9	23 minutes
Q2: gradient expression and table	3	8 minutes
Q2: graph, error bars and both lines	4	14 minutes
Q2: gradient, D, α and uncertainties	6	10 minutes
Q2: predicting L with its uncertainty	2	5 minutes
Check the plan against D1 to D10	–	3 minutes

Before writing the plan, jot down the D points you intend to cover, aiming for at least eight so that six survive marking.

Other May/June 2026 9702 papers

• 9702 Paper 12 (Multiple Choice)
• 9702 Paper 22 (AS Level Structured Questions)
• 9702 Paper 32 (Advanced Practical Skills)
• 9702 Paper 42 (A Level Structured Questions)

Practise and download

• Download 9702/52 and its mark scheme on the Learning Portal →
• All 9702 May/June 2026 papers: overview and marking patterns
• Try a free A Level Physics quiz

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Frequently asked questions

What was on 9702 Paper 52 May/June 2026? +

Two questions worth 15 marks each. Question 1 was a plan to test how the mean current I from a capacitor, charged and discharged by a vibrating reed switch, depends on the plate separation h. Question 2 was a data analysis question on a rod hung from two parallel strings, with T² plotted against 1/L².

How many marks is 9702/52 and how long is it? +

It is out of 30 marks and lasts 1 hour 15 minutes. It is an A Level paper, and both questions are compulsory.

How was the 9702/52 plan marked? +

In four parts: 2 marks for defining the problem (vary h and measure I, keep f constant), 4 for methods of data collection, 3 for the method of analysis, and 6 for additional detail chosen from ten listed points such as a safety precaution, measuring the plate diameter and keeping the plates parallel.

What graph should you plot for the 9702/52 capacitor plan? +

I against 1/h. The relationship is supported if the graph is a straight line through the origin, and K = gradient ÷ (AfE). A graph of lg I against lg h with a gradient of −1 was also accepted.

What was the mean value of D in 9702/52 Question 2(d)? +

The four readings 0.826, 0.829, 0.824 and 0.821 m average to 0.825 m, and the uncertainty is half the range, 0.004 m, giving D = (0.825 ± 0.004) m.

Where can I download 9702/52 May/June 2026 and its mark scheme? +

Both are free to download and print on the Tutopiya Learning Portal, on the Cambridge AS & A Level Physics 9702 past papers page.

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