Calculating uncertainties: OCR A‑Level Physics B questions

OCR A-Level Physics B past-paper questions on 2.0.8 Calculating uncertainties, 2016–2025, with mark schemes and examiner’s reports where available.

All 89 questions on Calculating uncertainties, as a list

June 2025, Paper 1, Q2 (1 mark): A student measures the change in temperature of some water when it is heated for 10 seconds. The student’s results are: Starting temperature = (53.4 ± 0.2) °C F
June 2025, Paper 1, Q36(b) (6 marks): (b)* A student carries out an experiment to determine the refractive index of a glass block using the apparatus shown in Fig. 36.2. Fig. 36.2 Laser (monochromat
June 2025, Paper 3, Q1(a)(i) (1 mark): Determine the absolute uncertainty in the measurement of time. Absolute uncertainty = ± s [1]
June 2025, Paper 3, Q1(a)(ii) (3 marks): Calculate the average velocity of the cupcake case. Include the uncertainty in your answer. Give your answer to an appropriate number of significant figures. Av
June 2025, Paper 3, Q2(a)(ii) (2 marks): Estimate the absolute uncertainty in the value of mass of one staple obtained by your method in part (a)(i). Uncertainty = ± g [2]
June 2025, Paper 3, Q2(b) (2 marks): The experiment is repeated several times for each value of current. With a current of 1.5 A, the number of staples needed to balance the wire horizontally was f
June 2025, Paper 3, Q4(b) (2 marks): One pair of data points is shown below. Time for ten oscillations = 10.4 s ± 0.5 s Mass = 0.50 kg ± 0.01 kg The student decides to ignore the uncertainty in the
June 2025, Paper 3, Q4(c)(ii) (3 marks): Calculate the uncertainty in the value of T 2 for the final data point and add these uncertainty bars to the graph. [3]
June 2025, AS Paper 1, Q25(c)(ii) (2 marks): Calculate a mean value for the Planck constant. Planck constant = × 10–34 J s [2]
June 2025, AS Paper 1, Q25(d) (2 marks): The class work out that their measurements produce an uncertainty in the value for the Planck constant of ±5%. Determine whether the class mean value for the Pl
June 2025, AS Paper 2, Q5(a) (4 marks): A manufacturer produces fixed resistors, which it sells in boxes of ten. A technician checks the values of ten resistors in a box using the circuit shown in Fig
June 2024, Paper 1, Q17 (1 mark): The density of a stone is determined by measuring its mass and volume, and using the equation density = mass ÷ volume. The mass of the stone measures 25.6 ± 0.2
June 2024, Paper 1, Q38(b)(i) (2 marks): thermometer measures temperature to the nearest 1 °C. Use this information to calculate the percentage uncertainties in the measured volume and temperature at 3
June 2024, Paper 2, Q2(c) (2 marks): Use the uncertainty in the diameter and current values to determine the uncertainty in your value for resistivity calculated above. Ignore any possible uncertai
June 2024, Paper 3, Q1(b)(ii) (2 marks): Draw lines of both the maximum and minimum gradients through the data points and uncertainty bars on the graph. [2]
June 2024, Paper 3, Q1(b)(iii) (5 marks): Calculate the mean rate of temperature rise in °C s–1 and its percentage uncertainty. Use the lines you drew for part (b)(ii). rate of temperature rise = °C s–1
June 2024, Paper 3, Q1(c)(ii) (4 marks): The potential difference across the heater is set at 9.6 V ± 2%. The current is 3.76 A ± 0.9%. Using these values and the value calculated in part (b)(iii), det
June 2024, Paper 3, Q2(a) (3 marks): Calculate the conductance of the semiconductor diode when the potential difference = 0.65 ± 0.02 V and the current = 7.5 ± 0.02 mA. Give the uncertainty in your
June 2024, AS Paper 1, Q17 (1 mark): In an experiment to determine the acceleration due to gravity, g, a ball bearing takes time t to fall distance s. The percentage uncertainty in each measurement
June 2024, AS Paper 1, Q27(g) (2 marks): The wavelength calculation uses the measurements of s, D and d. D was measured once using a metre ruler. Explain why taking more measurements of s will not redu
June 2024, AS Paper 2, Q8(b)(i) (5 marks): Use data from Table 8.1 to calculate the value of the acceleration when the trolley mass is 0.800 kg. Include the uncertainty in your answer.
June 2023, Paper 2, Q4(b)(ii) (3 marks): A student suggests that a more accurate determination of the velocity of sound could be made if the distance between several nodes was measured instead of the d
June 2023, Paper 3, Q2(a)(i) (2 marks): Calculate the mean value of striking voltage and its absolute uncertainty. Mean striking voltage = ± V [2]
June 2023, Paper 3, Q2(b)(i) (2 marks): Using the value for uncertainty found in (a)(i), add vertical error bars to all the plotted points and draw a steepest acceptable line through the error bars. [
June 2023, Paper 3, Q2(b)(ii) (2 marks): Hence calculate the absolute uncertainty of the gradient value. Absolute uncertainty of gradient = ± V m [2]
June 2023, Paper 3, Q2(c)(ii) (3 marks): The gradient of the line of best fit is 8.90 × 10–7 V m. Use this value to calculate a value of the Planck constant. Include a value for absolute uncertainty in
June 2023, AS Paper 1, Q20 (1 mark): The best estimate of the uncertainty in power at 2500 r.p.m. is: A ±1 kW B ±2 kW C ±3 kW D ±6 kW Your answer [1]
June 2023, AS Paper 2, Q5(b) (2 marks): The resistance of the resistor must be accurate to within ± 0.1 Ω. Calculate the maximum uncertainty ΔL which can be allowed in the length measurement. ΔL = m [
June 2023, AS Paper 2, Q7(a)(i) (4 marks): Use data from Fig. 7.1 to make as accurate an estimate as possible of the frequency f of the musical note together with the uncertainty Δf of the value. Show yo
June 2022, Paper 1, Q1 (1 mark): In an experiment to determine the focal length of a converging lens, a student sets up the apparatus shown in the diagram and observes a clear image on the scre
June 2022, Paper 1, Q36(c)(iii) (2 marks): The student assumed a constant uncertainty in the sines of the angle. Suggest and explain why this is unlikely to be the case. [2]
June 2022, Paper 1, Q36(c)(iv) (3 marks): The student calculated the value of the refractive index as 1.5. Use the graph to estimate a value for the uncertainty in the result. Explain your method. refra
June 2022, Paper 3, Q2(a)(ii) (4 marks): Before setting up the apparatus, the student took measurements with vernier calipers of the internal diameter of the tube containing the gas. The student create
June 2022, Paper 3, Q2(a)(iii) (2 marks): The height, h, of the column of air is measured using a standard laboratory metre rule. Estimate the absolute uncertainty in the measurement and justify your an
June 2022, Paper 3, Q4(b)(i) (1 mark): The line of best fit has been drawn on Fig. 4.2. Draw another line within the error bars shown, which has the greatest difference in gradient to the first line.
June 2022, Paper 3, Q4(b)(ii) (3 marks): The gradient of the line of best fit in Fig. 4.2 is 10 100 NM–1. Use this to calculate a value for the Young modulus of the wire. Use the line you have drawn to
June 2022, Paper 3, Q4(c)(ii) (2 marks): Suggest how the student could use multiple measurements to find the uncertainty of the diameter of the wire. [2]
June 2022, Paper 3, Q4(c)(iii) (3 marks): The student measures the diameter of another wire to be 0.35 ± 0.02 mm. Calculate the cross‑sectional area of the wire along with the absolute uncertainty. Area
June 2022, AS Paper 1, Q20 (1 mark): A student makes two measurements to determine the speed of a trolley rolling down a ramp. Measurement Measuring device Value Uncertainty Length of ramp metre ru
November 2021, Paper 1, Q3 (1 mark): Using the information in the box, which is the best estimate of the gradient of the graph, together with its uncertainty? 3.8 ± 0.7 cm N–1 A 3.8 ± 1.4 cm N–1 B
November 2021, Paper 3, Q1(a)(iv) (4 marks): Use the gradient to calculate the value for the acceleration of free fall. Include the uncertainty in your answer. acceleration of free fall = ± m s–2 [4]
November 2021, Paper 3, Q2(b)(ii) (3 marks): Estimate the uncertainty in the measurement of the distance between the slits and the screen and hence calculate the absolute uncertainty in the calculated valu
November 2021, AS Paper 1, Q18 (1 mark): The conductance G of a volume V of conducting putty rolled into a cylinder of length l is G = V ρl 2 Which combination of measurement precision will give the mo
November 2021, AS Paper 1, Q19 (1 mark): An engineer is estimating the load on a steel beam. There are 80 bricks on the beam. Each brick has mass 2.5 ± 0.1 kg. The true load on the beam most likely lie
November 2021, AS Paper 2, Q1(a) (4 marks): Ignoring the value of 0.34 mm, obtain values for the diameter d and its uncertainty, Δd. Show your working and give both values to an appropriate number of sign
November 2021, AS Paper 2, Q8(c)(iv) (4 marks): Draw appropriate straight lines on the graph and use these to find the value of the best- fit gradient and its uncertainty. From these values, obtain the speed
November 2020, Paper 2, Q3(b)(iv) (3 marks): The gradient of the ‘steepest-possible’ line is 1.74 × 10−6 V m. Use this to calculate an estimate of the uncertainty of the value for the Planck constant in (b
November 2020, Paper 3, Q1(b)(ii) (4 marks): The following readings were obtained: potential difference V = 10.5 ± 0.2 V current I = 2.3 ± 0.2 A. Calculate the power supplied to the heater per unit mass of
November 2020, Paper 3, Q3(b)(i) (4 marks): The gradient of the line is 83 m s–1. Calculate the speed of sound in air. Calculate the percentage uncertainty in your result by taking a ‘worst-fit’ line from
November 2020, AS Paper 1, Q20 (1 mark): A student calculates the resistivity of a material using the formula ρ = R πr 2 L The values of R, L and r are all measured with a percentage uncertainty of 1%.
November 2020, AS Paper 1, Q27(a) (1 mark): Complete the table with the missing mean value. [1]
November 2020, AS Paper 2, Q8(a) (3 marks): Sam uses a micrometer to make a number of measurements of the diameter of the wire at different points along its length. She records her readings in this dot-pl
November 2020, AS Paper 2, Q8(c)(ii) (3 marks): Sam decides that the uncertainties in m are far less than those in x, and plots the data as shown opposite. m ⎛ ⎞ Use the graph to find ⎝ ⎠ and its uncertainty.
June 2019, Paper 1, Q14 (1 mark): The resistance R of an unknown resistor is found by measuring the potential difference V across the resistor and the current I through it, using the equation R
June 2019, Paper 3, Q1(a)(ii) (3 marks): The absolute uncertainty in the measurement of each angle is ± 4°. Complete the table below with maximum and minimum values of the measured angles, and hence de
June 2019, Paper 3, Q2(c) (2 marks): The student is considering the uncertainty in her value for g. She thinks that data collected for the shorter pendulums have greater percentage uncertainty than
June 2019, Paper 3, Q4(c)(i) (2 marks): Fifteen apparently identical thermometers are available. Describe how the student can determine the uncertainty in the reading of the temperature by using all t
June 2019, Paper 3, Q4(c)(ii) (6 marks): Fig. 4.2 shows the graph of the data collected, including the uncertainty in the pressure readings. 120 110 100 pressure / kPa 90 80 70 60 250 270 290 310 330 3
June 2019, AS Paper 1, Q6 (1 mark): A student measures the potential difference across a wire = 1.05 V (±0.01 V) and the current through the wire = 0.34 A (±0.01 A). The percentage uncertainty in
June 2019, AS Paper 2, Q8(b) (2 marks): Lizzie uses the arrangement in Fig. 8.2 to measure object (u) and image (v) distances. As an object, she marks a black letter X on a thin sheet of paper. The im
June 2019, AS Paper 2, Q8(d) (3 marks): In her experiment, Lizzie obtains the following set of values of v and Δv for each chosen value of u. Complete the last two columns and plot the missing data on
June 2019, AS Paper 2, Q8(e) (6 marks): Lizzie has bought a new lens for her camera. It is marked with the focal length 50 mm (Fig. 8.1). She wants to measure its focal length as accurately as possibl
June 2018, Paper 1, Q38(b) (3 marks): Draw a line of best fit on the graph and measure its gradient with an uncertainty estimate. gradient = ± [3]
June 2018, Paper 1, Q38(c) (3 marks): Use the gradient to estimate an average wavelength for the light together with an uncertainty estimate. Make your method clear. wavelength = ± m [3]
June 2018, Paper 2, Q1(b)(ii) (2 marks): The highest p.d. recorded by the voltmeter is 3.00 ± 0.01 V. Calculate the maximum value of the resistance of the LDR at this point. Assume that there is no unc
June 2018, Paper 3, Q1(a)(ii) (3 marks): Calculate the cross sectional area A of the wire and the uncertainty. A = ± m2 [3]
June 2018, Paper 3, Q4(a)(i) (3 marks): Use the information in the dot-plot to find the mean D. Use the spread to determine the percentage uncertainty. mean D = ………………………… mm ± ……………… % [3]
June 2018, Paper 3, Q4(a)(ii) (3 marks): Calculate the cross sectional area A of the wire and include the uncertainty. A ………………………… ± ……………… m2 [3]
June 2018, Paper 3, Q4(c) (6 marks): This question is about an experiment to determine the Young modulus of a copper wire. The diameter D of the wire was measured using a micrometer screw gauge in
June 2018, AS Paper 1, Q29(d) (4 marks): The readings of p.d. for Fig. 29.2 were taken with a digital voltmeter. Five consecutive values were recorded at each temperature. The calculated mean output p.
June 2018, AS Paper 2, Q8(a)(i) (3 marks): For this LED, Alice and Bob obtain the following data for the first-order maximum. reading 1 reading 2 reading 3 y1 / cm 5.9 6.2 6.1 y2 / cm 6.1 5.9 6.3 Use the
June 2017, Paper 1, Q37(a) (2 marks): Fig. 37.2 shows the graph of velocity against time obtained by analysing the video recording. This method has an uncertainty of about ± 3% for velocity measurem
June 2017, Paper 2, Q9(a)(i) (1 mark): State the spread of the distance values. spread = ± m [1]
June 2017, Paper 2, Q9(a)(ii) (2 marks): A student suggests that the uncertainty in the distance values can be ignored when calculating the minimum angle that can be resolved because of the uncertainty
June 2017, Paper 2, Q9(a)(iii) (3 marks): Calculate a value for the minimum angle that can be resolved. Include an estimate of the uncertainty in your value. Explain how you estimated the uncertainty. m
June 2017, Paper 3, Q3(b)(i) (2 marks): Complete the table by calculating the mean change in balance reading and the corresponding values of force F for the last two current values. g = 9.8 N kg−1 [2]
June 2017, Paper 3, Q3(b)(ii) (2 marks): Use the table to determine the uncertainty in F. Explain your reasoning. [2]
June 2017, Paper 3, Q4(a)(ii) (1 mark): Ignoring the two potential outliers, calculate the range of the typical values on the dot‑plot. range = m [1]
June 2017, Paper 3, Q4(a)(iii) (2 marks): Calculate the mean of the values within the range calculated in (a)(ii). Mark this on the dot‑plot above. mean = m [2]
June 2017, Paper 3, Q4(c)(ii) (4 marks): Use the uncertainty bars on Fig. 4.6 to determine the maximum and minimum values for the power of the lens. Use these values to determine the percentage uncerta
June 2017, AS Paper 1, Q16 (1 mark): The length of a square paving stone is 0.500 ± 0.002 m. The percentage uncertainty in this measurement is 0.4%. The area of the paving slab is 0.250 m2. What is
June 2017, AS Paper 1, Q28(c) (4 marks): The student measured the frequency of the sound wave at 560 ± 30 Hz. The uncertainties in the distances from each speaker to position C are ± 0.02 m. Calculate
June 2017, AS Paper 2, Q8(a)(ii) (3 marks): The time recorded by the data-logger when a trolley passes the light gate is 0.1453 s. Calculate the mean speed of the trolley and its uncertainty. Give both va
June 2016, AS Paper 1, Q29(a)(i) (2 marks): The single 1.6 s reading was treated as an outlier. Calculate the mean time of drop for the remaining data and estimate the uncertainty. mean time of drop = ± s
June 2016, AS Paper 1, Q29(a)(iii) (3 marks): The vertical distance is measured as 1.85 ± 0.02 m due to the uncertainty in the release position. Calculate your best estimate for the terminal velocity of the
June 2016, AS Paper 2, Q6(a) (3 marks): Anna correctly records the values of u and v and their uncertainties for s = 0.24 m as follows. u / m s–1 v / m s–1 s / m 0.24 1.40 ± 0.04 2.61 ± 0.03 Table 6.3
June 2016, AS Paper 2, Q6(c)(i) (2 marks): Use the data from Table 6.3 to show that the uncertainty in v2 – u2 is 0.3 m2 s–2 when s = 0.24 m. [2]
June 2016, AS Paper 2, Q6(c)(ii) (2 marks): Anna decides to use this value of uncertainty for each uncertainty bar in her graph of v2 – u2 against s. Suggest why this may not be accurate when s is much gr
June 2016, AS Paper 2, Q6(d) (3 marks): Anna repeats her measurements for five further values of s and plots the graph of Fig. 6.4. Draw suitable lines on the graph and use them to determine the value

Questions, mark schemes and examiner’s reports are © OCR, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? OCR A-Level Physics B past papers.

The Plumi iPad app also offers exam-style questions with AI feedback on your handwritten working.

1,881 questions