plumiMeasurements and uncertainties: OCR A‑Level Physics A questions
Every OCR A-Level Physics A exam question on 2.2.1 Measurements and uncertainties, 2016–2025, with its mark scheme and examiner’s report.
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Q23(c)
The whole paper ↗
Q2(c)(i)
The whole paper ↗![June 2025 Paper 3, question 2(c)(i): Draw a worst acceptable line on the graph. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun25-02-ci-qp.webp?v=3)
Q2(c)(ii)
The whole paper ↗![June 2025 Paper 3, question 2(c)(ii): Use your worst acceptable line to calculate the percentage uncertainty in the gradient of the best fit line. gradient = 2.81 ± N1/2m–1% [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun25-02-cii-qp.webp?v=3)
![June 2025 Paper 3, question 2(c)(iii): Calculate a value for the mains frequency, f, including a percentage uncertainty. f = Hz ± % [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun25-02-ciii-qp.webp?v=3)
Q2(c)(iv)
The whole paper ↗![June 2025 Paper 3, question 2(c)(iv): Evaluate the accuracy of your value for f, given that the true value is 50.0 Hz. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun25-02-civ-qp.webp?v=3)
Q4(b)(i)
The whole paper ↗![June 2025 Paper 3, question 4(b)(i): The student concludes that the voltmeter has a zero error of 300 V. Explain their reasoning. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun25-04-bi-qp.webp?v=3)
Q22(b)
The whole paper ↗
Q2(a)(ii)
The whole paper ↗![June 2025 AS Paper 2, question 2(a)(ii): Calculate the percentage uncertainty in m. percentage uncertainty = % [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun25-02-aii-qp.webp?v=3)
Q2(b)
The whole paper ↗![June 2024 Paper 3, question 2(b): The students write in their lab books, “Our data is precise”. Evaluate this statement. [2] Question 2 continues on page 6](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun24-02-b-qp.webp?v=3)
Q2(d)(iv)
The whole paper ↗
Q2(e)(i)
The whole paper ↗![June 2024 Paper 3, question 2(e)(i): State the type of error caused by this mistake. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun24-02-ei-qp.webp?v=3)
Q2(e)(ii)
The whole paper ↗![June 2024 Paper 3, question 2(e)(ii): Explain the effect that this error would have had on the calculated value of R. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun24-02-eii-qp.webp?v=3)
Q26(c)
The whole paper ↗![June 2024 AS Paper 1, question 26(c): An accepted value for the Planck constant is 6.63 × 10–34 J s. Calculate the percentage uncertainty in the student’s results. percentage uncertainty = % [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15601-jun24-26-c-qp.webp?v=3)
Q4(a)(i)
The whole paper ↗![June 2024 AS Paper 2, question 4(a)(i): Explain how to determine the thickness of the prism accurately in the laboratory. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun24-04-ai-qp.webp?v=3)
Q23(a)(ii)
The whole paper ↗![June 2023 Paper 1, question 23(a)(ii): Calculate the percentage uncertainty in the calculated value of the distance to Polaris A. percentage uncertainty = % [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55601-jun23-23-aii-qp.webp?v=3)
All 71 questions on Measurements and uncertainties, as a list
- June 2025, Paper 1, Q23(c) (2 marks): Estimate the percentage uncertainty in the distance calculated in part (b) using the width of the emission line in the diagram. percentage uncertainty = +/– % [
- June 2025, Paper 2, Q9 (1 mark): The radius R of the nucleus of an unknown isotope with nucleon number is calculated using the formula R = r0A1/3 , where r0 is a constant. The percentage uncert
- June 2025, Paper 3, Q2(c)(i) (1 mark): Draw a worst acceptable line on the graph. [1]
- June 2025, Paper 3, Q2(c)(ii) (3 marks): Use your worst acceptable line to calculate the percentage uncertainty in the gradient of the best fit line. gradient = 2.81 ± N1/2m–1% [3]
- June 2025, Paper 3, Q2(c)(iii) (3 marks): Calculate a value for the mains frequency, f, including a percentage uncertainty. f = Hz ± % [3]
- June 2025, Paper 3, Q2(c)(iv) (2 marks): Evaluate the accuracy of your value for f, given that the true value is 50.0 Hz. [2]
- June 2025, Paper 3, Q4(b)(i) (1 mark): The student concludes that the voltmeter has a zero error of 300 V. Explain their reasoning. [1]
- June 2025, AS Paper 1, Q15 (1 mark): The mass of a cube of a material is measured to a percentage uncertainty of 8%. The length of each side of the cube is measured to a percentage uncertainty of 2
- June 2025, AS Paper 1, Q22(b) (3 marks): The table shows the refractive index n for three different types of glass. Type of glass Refractive index, n X 1.47 < n < 1.49 Y 1.49 < n < 1.50 Z 1.51 < n < 1.
- June 2025, AS Paper 2, Q2(a)(ii) (2 marks): Calculate the percentage uncertainty in m. percentage uncertainty = % [2]
- June 2024, Paper 2, Q5 (1 mark): The image shows a micrometer that is being used to measure the diameter of a wire. The micrometer has a zero error of +0.07 mm. The measured value of the diamet
- June 2024, Paper 3, Q2(b) (2 marks): The students write in their lab books, “Our data is precise”. Evaluate this statement. [2] Question 2 continues on page 6
- June 2024, Paper 3, Q2(d)(iv) (2 marks): The value of C is known to be 1000 μF ± 5%. Use your gradient value from (iii) to find a value for R, in units of k Ω, including an absolute uncertainty. R = ±
- June 2024, Paper 3, Q2(e)(i) (1 mark): State the type of error caused by this mistake. [1]
- June 2024, Paper 3, Q2(e)(ii) (1 mark): Explain the effect that this error would have had on the calculated value of R. [1]
- June 2024, AS Paper 1, Q19 (1 mark): A student makes measurements to determine the total energy W transferred by a filament lamp. They record the measurements shown below. Potential difference / V
- June 2024, AS Paper 1, Q26(c) (2 marks): An accepted value for the Planck constant is 6.63 × 10–34 J s. Calculate the percentage uncertainty in the student’s results. percentage uncertainty = % [2]
- June 2024, AS Paper 2, Q4(a)(i) (2 marks): Explain how to determine the thickness of the prism accurately in the laboratory. [2]
- June 2023, Paper 1, Q23(a)(ii) (2 marks): Calculate the percentage uncertainty in the calculated value of the distance to Polaris A. percentage uncertainty = % [2]
- June 2023, Paper 2, Q2 (1 mark): The accepted value of g is 9.81 ms–2. In an experiment to verify the value of g, students obtained 2 a value of 10.20 ms–2. What is the percentage difference be
- June 2023, Paper 3, Q2(a)(ii) (3 marks): The student calculates the value of the diameter as d = 0.455 ± 0.005 mm. Explain how the student calculated the value of the diameter, and its uncertainty, fro
- June 2023, AS Paper 1, Q21(c)(ii) (3 marks): The student records the following results for a copper wire. L = 2.0 m ± 0.05 % A = 2.9 × 10–8 m2 ± 2 % k = 1670 N m–1 ± 1.25 % Calculate the value of the Young
- June 2023, AS Paper 1, Q21(c)(iii) (2 marks): The student researches the Young modulus of copper. They find a value of 1.17 × 1011 N m–2. Determine whether this value is consistent with your answer to (c)(i
- June 2023, AS Paper 2, Q6(b) (1 mark): The switch is initially open. The voltmeter reading is 5.72 V The following voltmeters are available: A: 0–2 V, ± 0.001 V B: 0–2 V, ± 0.01 V C: 0–2 V, ± 0.1 V D
- June 2022, Paper 1, Q2 (1 mark): The diameter of a wire is measured in five different places along its length. The results are shown below. 1.92 mm 1.88 mm 1.90 mm 1.86 mm 1.89 mm What is the a
- June 2022, Paper 1, Q22(a) (2 marks): A team of astronomers have measurements to determine the peak surface temperature T and luminosity L of a distant star. They plan to use Stefan’s law to estimat
- June 2022, Paper 2, Q21(b)(iii) (4 marks): The student plots a straight-line graph of E0 against sin θ. Determine f, including the absolute uncertainty. Write your value of f to 2 significant figures. I0
- June 2022, Paper 3, Q2(b)(iii) (1 mark): Draw a line of worst fit on Fig. 2.2. [1]
- June 2022, Paper 3, Q2(b)(iv) (3 marks): Use your line of worst fit to calculate the percentage uncertainty in g. percentage uncertainty = % [3]
- June 2022, Paper 3, Q2(b)(v) (2 marks): Use the true value of g (9.81 m s–2) to evaluate the accuracy of the student’s value of g from this experiment. Include a calculation in your answer. [2]
- June 2022, AS Paper 2, Q1(a) (3 marks): Describe how the student can determine r accurately in the laboratory. [3]
- June 2022, AS Paper 2, Q7(c)(iii) (2 marks): Calculate the percentage uncertainty in R. percentage uncertainty = % [2]
- November 2021, Paper 1, Q17(a) (3 marks): A metal strip has thickness t, as shown below. metal strip t Five measurements of the thickness t at different positions along the length of the strip are shown
- November 2021, Paper 1, Q23(a) (4 marks): Here is some data on the star Aa1. radius = (1.90 ± 0.14) × 109 m • mass = (6.31 ± 0.42) × 1030 kg. • Calculate the gravitational field strength g at the surfac
- November 2021, Paper 3, Q5(c)(ii) (2 marks): The percentage uncertainty in the value of F can be written as 100 ΔF F where ΔF is the absolute uncertainty in F. Use the rules for combining uncertainties to
- November 2021, AS Paper 1, Q22(b) (3 marks): Calculate the absolute uncertainty in g. Write your answer to 2 significant figures. absolute uncertainty = m s−2 [3]
- November 2021, AS Paper 2, Q7(a)(iii) (1 mark): Draw a worst acceptable straight line. [1]
- November 2021, AS Paper 2, Q7(a)(iv) (3 marks): Use your worst acceptable straight line to determine the percentage uncertainty in your value for h. percentage uncertainty = % [3]
- November 2020, Paper 1, Q13 (1 mark): The Young modulus E of a metal can be determined using the expression E = 4F επd2 , where F is the tension in the wire, d is the diameter of the wire and ε is t
- November 2020, Paper 2, Q19(b)(ii) (7 marks): The researcher plots data points on a λ2 against 1 V grid, as shown below. 2.0 1.5 λ2 / 10–25 m2 1.0 0.5 0 0 10 20 1 / 10–4 V–1 V 17 1 Calculate the percentage
- November 2020, Paper 3, Q2(b)(iii) (4 marks): Draw on the graph a straight line of worst fit. Use this line to determine the absolute uncertainty in your value of C0. Write your answer to an appropriate num
- November 2020, AS Paper 1, Q22(b) (3 marks): The following items of data are collected for the parachute. v = 1.20 ± 0.12 m s−1 • • F = 4.00 ± 0.24 N Calculate the absolute uncertainty in k. Write your ans
- November 2020, AS Paper 1, Q24(a)(i) (1 mark): Suggest why the graph does not pass through the origin. [1]
- November 2020, AS Paper 2, Q3(b)(i) (1 mark): Draw a worst acceptable straight line. [1]
- November 2020, AS Paper 2, Q3(b)(ii) (1 mark): Determine the gradient of your worst acceptable line. gradient of worst acceptable line = m kg−1 [1]
- November 2020, AS Paper 2, Q3(b)(iii) (2 marks): Determine the percentage uncertainty in k. percentage uncertainty = % [2]
- June 2019, Paper 1, Q3 (1 mark): A solid cylindrical glass rod has length 20.0 ± 0.1 cm and diameter 5.00 ± 0.01 mm. What is the percentage uncertainty in the calculated volume of this rod? A 0
- June 2019, Paper 3, Q6(d) (2 marks): In their laboratory notes, one student writes about the accuracy of the measurements whereas the other writes about their precision. Define these terms. accurac
- June 2019, AS Paper 1, Q2 (1 mark): Four students each carry out an experiment to determine the acceleration of free fall g. Which is the least accurate value? A (9.0 ± 1.0) m s–2 B (9.5 ± 0.1) m
- June 2019, AS Paper 2, Q3(a)(i) (1 mark): State the name of a suitable measuring instrument to measure the diameter of the ball. [1]
- June 2019, AS Paper 2, Q3(a)(ii) (2 marks): Calculate the mean diameter d of the ball. Include the absolute uncertainty in d. d = ± cm [2]
- June 2019, AS Paper 2, Q3(a)(v) (2 marks): Determine the percentage uncertainty in ρ. percentage uncertainty = % [2]
- June 2018, Paper 2, Q6 (1 mark): Which is the best value for the elementary charge e in terms of both accuracy and precision? (1.5 ± 0.5) # 10−19 C A (1.5 ± 0.4) # 10−19 C B (1.7 ± 0.2) # 10−19
- June 2018, Paper 2, Q11 (1 mark): The acoustic impedance Z of a material in the shape of a cube can be determined using the equation Mc Z = 3 L where M is the mass of the material, L is the leng
- June 2018, Paper 2, Q20(a)(iv) (4 marks): Identify the two types of errors shown by the data in Fig. 20.1 and suggest how you could have refined the experiment to reduce or eliminate these errors. [4]
- June 2018, Paper 3, Q4(b)(i) (2 marks): Complete the missing value of v 2 in the table including the absolute uncertainty. [2]
- June 2018, Paper 3, Q4(c)(ii) (4 marks): Assume that the best-fit straight line through the data points gives 9.5 m s–2 for the experimental value of g. Draw a worst-fit line through the data points on
- June 2018, Paper 3, Q4(d) (4 marks): It is suspected that the card on the trolley did not pass at right angles through the light beam. Discuss, without doing any calculations, the effect this may h
- June 2018, AS Paper 1, Q8 (1 mark): A student determines the power P dissipated in a resistor. The measured values of the current I in 8 the resistor and the resistance R of the resistor are: I =
- June 2018, AS Paper 2, Q6(c)(iii) (2 marks): Determine the percentage uncertainty in ρ. percentage uncertainty = % [2]
- June 2017, Paper 1, Q5 (1 mark): Which is the best estimate of the area of a rectangular field of length 98 ± 3 m and width 47 ± 2 m? 4600 ± 5 m2 A 4600 ± 6 m2 B 4600 ± 300 m2 C 4606 ± 337 m2 D
- June 2017, Paper 1, Q17(d) (2 marks): Describe, without doing any calculations, how you could use Fig. 17.3 to determine the actual uncertainty in the value of absolute zero in (c)(ii). [2]
- June 2017, Paper 3, Q3(b)(i) (1 mark): Complete the missing value of ln (V / V) and its absolute uncertainty in the table above.
- June 2017, Paper 3, Q3(b)(iii) (4 marks): Use the graph to determine a value for C. Include the absolute uncertainty and an appropriate unit in your answer. C = ± unit [4]
- June 2017, AS Paper 1, Q8 (1 mark): Two resistors of resistances 120 Ω and 500 Ω are connected in parallel. The percentage uncertainty in the value of resistance of each resistor is 10%. What is t
- June 2017, AS Paper 1, Q26(b) (3 marks): Describe and explain how you could make use of standard laboratory equipment to determine the mass per unit length μ of the wire. State how you would make your
- June 2017, AS Paper 1, Q27(b)(iv) (2 marks): Explain, without doing any calculations, how you could use Fig. 27 to determine the percentage uncertainty in h. [2]
- June 2017, AS Paper 2, Q5(b)(ii) (5 marks): The screen is at a distance of 4.50 ! 0.02 m from the slits and the slit separation is 0.56 ! 0.02 mm. 1. Use Fig. 5.2 to determine the wavelength λ of the ligh
- June 2016, AS Paper 1, Q13 (1 mark): A student determines the resistance R of a filament lamp by measuring the potential difference V across it and the current I in it. The values recorded by the s
- June 2016, AS Paper 1, Q22(a) (1 mark): Fig. 22 shows that the straight line does not pass through the origin because of a systematic error in the measurement of the braking distance x. The u 2 values
- June 2016, AS Paper 2, Q5(c)(ii) (1 mark): Each length is measured to the nearest millimetre using a ruler. Determine the percentage uncertainty in L2 for L = 0.049 m. percentage uncertainty = % [1]
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