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E.m.f. and p.d: OCR A‑Level Physics A questions

Every OCR A-Level Physics A exam question on 4.2.2 E.m.f. and p.d, 2016–2025, with its mark scheme and examiner’s report.

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1,877 questions

  1. Q4(a)

    June 2025 · AS Paper 2

    2 marks4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2025 AS Paper 2, question 4(a): The quantities e.m.f. and potential difference (p.d.) are both measured in volts, V. Describe one other similarity and one difference between e.m.f. and p.d. si

  2. Q5(a)(ii)

    June 2024 · Paper 3

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2024 Paper 3, question 5(a)(ii): e.m.f. of a cell. [1]

  3. Q19(c)(i)

    June 2023 · Paper 2

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2023 Paper 2, question 19(c)(i): Calculate the work done W on the electrons. W = J [1]

  4. Q23(a)

    June 2023 · AS Paper 1

    2 marks4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2023 AS Paper 1, question 23(a): Calculate the work done on an electron as it moves from the metal plate to the electrode. work done = J [2]

  5. Q18(a)

    June 2022 · Paper 2

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2022 Paper 2, question 18(a): Compare the e.m.f. of the battery and the potential difference (p.d.) across the variable resistor in terms of energy transfers or changes. [1]

  6. Q18

    June 2022 · AS Paper 1

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2022 AS Paper 1, question 18: What is the total energy E gained by N electrons travelling through a potential difference V? A E = N × V E = V × 10–19 B E = V × 1.60 × 10–19 C E = N × V × 1.6

  7. Q25(a)

    June 2022 · AS Paper 1

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2022 AS Paper 1, question 25(a): Potential difference (p.d.) and electromotive force (e.m.f.) can both be defined in terms of transfer of energy per unit charge. State one other similarity betw

  8. Q2

    November 2021 · AS Paper 1

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    November 2021 AS Paper 1, question 2: Which of the following is not a source of electromotive force (e.m.f.)? A chemical cell B light-dependent resistor C power supply D solar cell Your answer [1]

  9. Q4

    November 2020 · AS Paper 1

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    November 2020 AS Paper 1, question 4: An electron with initial kinetic energy of 100 eV and initial speed of 5.9 × 106 m s−1 is accelerated 4 through a potential difference of 250 V. What is the fin

  10. Q25(b)(i)

    June 2019 · AS Paper 1

    3 marks4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2019 AS Paper 1, question 25(b)(i): Show that the final speed of each electron is about 9 × 106 m s–1. [3]

  11. Q14

    June 2018 · AS Paper 1

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2018 AS Paper 1, question 14: The total energy gained by 20 electrons travelling through a potential difference V is 30 keV. What is the potential difference V? A 1.5 V B 3.0 V C 1500 V D 30

  12. Q2

    June 2017 · Paper 2

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2017 Paper 2, question 2: One million electrons travel between two points in a circuit. The total energy gained by the electrons is 1.6 × 10−10 J. What is the potential difference betwee

  13. Q15

    June 2016 · AS Paper 1

    1 mark4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2016 AS Paper 1, question 15: An electron gun is used to accelerate electrons from rest through a voltage V. The electrons emerge with a speed u. electron u path voltage – + V The voltage in

  14. Q25(a)(i)

    June 2016 · AS Paper 1

    2 marks4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2016 AS Paper 1, question 25(a)(i): The terms electromotive force (e.m.f.) and potential difference (p.d.) are terms associated with the circuit. State one similarity and one difference between e.

  15. Q8(a)

    June 2016 · AS Paper 2

    3 marks4.2.2 E.m.f. and p.d
    The whole paper ↗
    June 2016 AS Paper 2, question 8(a): Show that the final speed v of the electrons is 1.0 × 107 m s−1. [3]
All 15 questions on E.m.f. and p.d, as a list
  1. June 2025, AS Paper 2, Q4(a) (2 marks): The quantities e.m.f. and potential difference (p.d.) are both measured in volts, V. Describe one other similarity and one difference between e.m.f. and p.d. si
  2. June 2024, Paper 3, Q5(a)(ii) (1 mark): e.m.f. of a cell. [1]
  3. June 2023, Paper 2, Q19(c)(i) (1 mark): Calculate the work done W on the electrons. W = J [1]
  4. June 2023, AS Paper 1, Q23(a) (2 marks): Calculate the work done on an electron as it moves from the metal plate to the electrode. work done = J [2]
  5. June 2022, Paper 2, Q18(a) (1 mark): Compare the e.m.f. of the battery and the potential difference (p.d.) across the variable resistor in terms of energy transfers or changes. [1]
  6. June 2022, AS Paper 1, Q18 (1 mark): What is the total energy E gained by N electrons travelling through a potential difference V? A E = N × V E = V × 10–19 B E = V × 1.60 × 10–19 C E = N × V × 1.6
  7. June 2022, AS Paper 1, Q25(a) (1 mark): Potential difference (p.d.) and electromotive force (e.m.f.) can both be defined in terms of transfer of energy per unit charge. State one other similarity betw
  8. November 2021, AS Paper 1, Q2 (1 mark): Which of the following is not a source of electromotive force (e.m.f.)? A chemical cell B light-dependent resistor C power supply D solar cell Your answer [1]
  9. November 2020, AS Paper 1, Q4 (1 mark): An electron with initial kinetic energy of 100 eV and initial speed of 5.9 × 106 m s−1 is accelerated 4 through a potential difference of 250 V. What is the fin
  10. June 2019, AS Paper 1, Q25(b)(i) (3 marks): Show that the final speed of each electron is about 9 × 106 m s–1. [3]
  11. June 2018, AS Paper 1, Q14 (1 mark): The total energy gained by 20 electrons travelling through a potential difference V is 30 keV. What is the potential difference V? A 1.5 V B 3.0 V C 1500 V D 30
  12. June 2017, Paper 2, Q2 (1 mark): One million electrons travel between two points in a circuit. The total energy gained by the electrons is 1.6 × 10−10 J. What is the potential difference betwee
  13. June 2016, AS Paper 1, Q15 (1 mark): An electron gun is used to accelerate electrons from rest through a voltage V. The electrons emerge with a speed u. electron u path voltage – + V The voltage in
  14. June 2016, AS Paper 1, Q25(a)(i) (2 marks): The terms electromotive force (e.m.f.) and potential difference (p.d.) are terms associated with the circuit. State one similarity and one difference between e.
  15. June 2016, AS Paper 2, Q8(a) (3 marks): Show that the final speed v of the electrons is 1.0 × 107 m s−1. [3]

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