plumiInternal resistance: OCR A‑Level Physics A questions
Every OCR A-Level Physics A exam question on 4.3.2 Internal resistance, 2016–2025, with its mark scheme and examiner’s report.
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Q5(a)(i)
The whole paper ↗![June 2024 Paper 3, question 5(a)(i): internal resistance of a cell [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun24-05-ai-qp.webp?v=3)
Q5(b)
The whole paper ↗
Q5(c)
The whole paper ↗
Q21(a)
The whole paper ↗![June 2024 AS Paper 1, question 21(a): The current in the circuit is I. Show that the power P delivered to the bulb is given by P = 3I (ε – Ir ) [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15601-jun24-21-a-qp.webp?v=3)
Q21(b)
The whole paper ↗![June 2024 AS Paper 1, question 21(b): Suggest why a torch battery with a large internal resistance may be undesirable. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15601-jun24-21-b-qp.webp?v=3)
Q7(a)(i)
The whole paper ↗![June 2024 AS Paper 2, question 7(a)(i): Suggest why a student deduces that the e.m.f. ε of the battery has the value of 4.57 V. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun24-07-ai-qp.webp?v=3)
Q7(a)(ii)
The whole paper ↗![June 2024 AS Paper 2, question 7(a)(ii): Show that the resistance r is approximately 3.9 Ω. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun24-07-aii-qp.webp?v=3)
Q7(c)(i)
The whole paper ↗![June 2024 AS Paper 2, question 7(c)(i): The ammeter reading [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun24-07-ci-qp.webp?v=3)
Q7(c)(ii)
The whole paper ↗![June 2024 AS Paper 2, question 7(c)(ii): The voltmeter reading [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun24-07-cii-qp.webp?v=3)
Q2(b)(i)
The whole paper ↗![June 2023 Paper 3, question 2(b)(i): Show that 1 I = 4ρ ⎛ ⎞ πεd 2 L + r ⎝ ⎠ ε [3] Question 2 continues on page 6](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun23-02-bi-qp.webp?v=3)
Q2(b)(ii)
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Q6(c)(ii)
The whole paper ↗![June 2023 AS Paper 2, question 6(c)(ii): Determine values for E and r. E = V r = Ω [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun23-06-cii-qp.webp?v=3)
Q6(d)
The whole paper ↗![June 2023 AS Paper 2, question 6(d): The resistor R is changed to a lower value. State and explain the change, if any, in the ammeter and voltmeter readings when the switch is closed. [4]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun23-06-d-qp.webp?v=3)
Q18(c)(i)
The whole paper ↗![June 2022 Paper 2, question 18(c)(i): Show that 1 I = R E + r E. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55602-jun22-18-ci-qp.webp?v=3)
Q18(c)(ii)
The whole paper ↗
All 35 questions on Internal resistance, as a list
- June 2025, Paper 2, Q7 (1 mark): A cell has electromotive force (e.m.f.) 1.50 V and internal resistance 1.2 Ω. It is connected in a circuit as shown below. What is the terminal potential differ
- June 2025, AS Paper 1, Q18 (1 mark): A cell with an e.m.f. of 1.50 V and internal resistance of 0.50 Ω is connected to a resistor of resistance 20 Ω. An ammeter is connected in series. 0.50Ω A 20Ω
- June 2024, Paper 2, Q10 (1 mark): A student uses the circuit below to determine the electromotive force (e.m.f.) and internal resistance of a battery. A V They measure the current and potential
- June 2024, Paper 3, Q5(a)(i) (1 mark): internal resistance of a cell [1]
- June 2024, Paper 3, Q5(b) (3 marks): A cell has internal resistance r = 1.2 Ω and e.m.f. ε = 5.6 V. When the cell is connected to a filament lamp B, as shown in the circuit diagram below, the curre
- June 2024, Paper 3, Q5(c) (6 marks): A student wants to determine the internal resistance r and the e.m.f. ε of a different cell. The student knows that the internal resistance is approximately 0.1
- June 2024, AS Paper 1, Q17 (1 mark): Which of the following is a correct statement about the e.m.f. of a cell ? A It is equal to the energy transferred from chemical energy per volt. B It is equal
- June 2024, AS Paper 1, Q21(a) (3 marks): The current in the circuit is I. Show that the power P delivered to the bulb is given by P = 3I (ε – Ir ) [3]
- June 2024, AS Paper 1, Q21(b) (2 marks): Suggest why a torch battery with a large internal resistance may be undesirable. [2]
- June 2024, AS Paper 2, Q7(a)(i) (1 mark): Suggest why a student deduces that the e.m.f. ε of the battery has the value of 4.57 V. [1]
- June 2024, AS Paper 2, Q7(a)(ii) (1 mark): Show that the resistance r is approximately 3.9 Ω. [1]
- June 2024, AS Paper 2, Q7(c)(i) (1 mark): The ammeter reading [1]
- June 2024, AS Paper 2, Q7(c)(ii) (1 mark): The voltmeter reading [1]
- June 2023, Paper 3, Q2(b)(i) (3 marks): Show that 1 I = 4ρ ⎛ ⎞ πεd 2 L + r ⎝ ⎠ ε [3] Question 2 continues on page 6
- June 2023, Paper 3, Q2(b)(ii) (6 marks): The student plots a graph of 1 I against L. The data points, error bars, line of best fit and a line of worst fit are shown in the graph below. 4.0 1 A – 1 I 3.
- June 2023, AS Paper 1, Q7 (1 mark): Two identical cells are connected in series in a circuit with a resistor X of resistance 145 Ω. The e.m.f. of each cell is 3.0 V. The current in X is 0.040 A. 3
- June 2023, AS Paper 2, Q6(c)(ii) (3 marks): Determine values for E and r. E = V r = Ω [3]
- June 2023, AS Paper 2, Q6(d) (4 marks): The resistor R is changed to a lower value. State and explain the change, if any, in the ammeter and voltmeter readings when the switch is closed. [4]
- June 2022, Paper 2, Q18(c)(i) (2 marks): Show that 1 I = R E + r E. [2]
- June 2022, Paper 2, Q18(c)(ii) (4 marks): The student varies R and measures the current I. The student plots a graph of 1 I against R. 1.2 1 / A–1 I 0.8 0.4 0 0 1.0 2.0 3.0 4.0 R / Ω 1 Use the graph to
- June 2022, AS Paper 1, Q8 (1 mark): A cell of electromotive force (e.m.f.) 1.2 V is connected to a wire of resistance 6.0 Ω. 1.2 V r 6.0 Ω 0.90 V The potential difference across the wire is 0.90 V
- November 2021, Paper 2, Q18(a)(ii) (3 marks): Calculate the current I shown by the ammeter. I = A [3]
- November 2021, Paper 2, Q18(b) (6 marks): (b)* A student is doing an experiment to determine the e.m.f. E of a cell and its internal resistance r. The circuit diagram of the arrangement is shown below.
- November 2021, AS Paper 2, Q5(a) (2 marks): Use Kirchhoff’s second law to show that V = E – Ir. [2]
- November 2021, AS Paper 2, Q5(b) (2 marks): The resistance R of the variable resistor is varied. I and V are recorded for each value of R. A graph of V (y-axis) against I (x-axis) is plotted. 5.8 V / V 5.
- November 2020, AS Paper 1, Q25(a) (2 marks): A student connects a calibrated 10.0 Ω resistor across a chemical cell of electromotive force (e.m.f.) 1.50 V. The student expects the current in the resistor t
- June 2019, Paper 2, Q18(c)(ii) (2 marks): Show that the gradient of the line is ρ AE, where ρ is the resistivity of the material of the wire, A is the area of cross-section of the wire and E is the e.m.
- June 2019, AS Paper 1, Q23(a)(i) (4 marks): Calculate the current I in the circuit. Write your value to an appropriate number of significant figures. I = A [4]
- June 2018, Paper 2, Q16(b)(ii) (8 marks): Fig. 16.2 shows the components L and R connected in series to a battery of e.m.f. 6.0 V. 6.0 V r L R Fig. 16.2 The resistor R is a cylindrical rod of length 8.0
- June 2018, AS Paper 1, Q7 (1 mark): Two resistors of resistances 2.0 Ω and 4.0 Ω are connected in series across the terminals of a cell of e.m.f. 1.4 V and internal resistance 1.0 Ω. 1.4 V 4.0 Ω 1
- June 2018, AS Paper 2, Q6(b) (3 marks): Fig. 6.2 shows components X and Y connected in parallel to a battery of e.m.f. 9.6 V and internal resistance r. 9.6 V r X V Y Fig. 6.2 13 The voltmeter reading
- June 2017, Paper 2, Q18(b) (6 marks): (b)* A group of students are investigating the power dissipated in a variable resistor connected across the terminals of a cell. The cell has e.m.f. 1.5 V. The
- June 2017, AS Paper 1, Q24(b)(i) (3 marks): When the contact X is in the middle of the wire, the voltmeter reading is 1.2 V. Calculate the internal resistance r of the cell. r = Ω [3]
- June 2017, AS Paper 1, Q24(b)(ii) (3 marks): The contact X is now moved along the wire from A to B. The distance of the contact X from A is d. Fig. 24.3 shows the variation of the potential difference V ac
- June 2016, AS Paper 1, Q25(b) (4 marks): A student is given a chemical cell, an ammeter, a voltmeter, a variable resistor and a number of connecting wires. Design a laboratory experiment to determine t
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