plumiPower: OCR A‑Level Physics A questions
Every OCR A-Level Physics A exam question on 4.2.5 Power, 2016–2025, with its mark scheme and examiner’s report.
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Calculations
Q21(d)
The whole paper ↗
Q21(e)
The whole paper ↗![June 2025 Paper 2, question 21(e): State the unit used to measure the electrical energy supplied to homes in the UK. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55602-jun25-21-e-qp.webp?v=3)
Q1(d)
The whole paper ↗![June 2025 Paper 3, question 1(d): Suggest two ways that the horizontal current may affect the atmosphere. 1 2 [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun25-01-d-qp.webp?v=3)
Q23(a)
The whole paper ↗![June 2025 AS Paper 1, question 23(a): Calculate the percentage efficiency of the microwave oven. percentage efficiency = % [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15601-jun25-23-a-qp.webp?v=3)
Q7(b)(i)
The whole paper ↗![June 2024 AS Paper 2, question 7(b)(i): the energy E dissipated in r. E = J [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun24-07-bi-qp.webp?v=3)
![June 2023 Paper 2, question 4: A 200 W heater is used for 90 minutes. The cost per kWh is 13 pence. How much did it cost to use the heater? A 3.9p B 39p C £2.34 D £23.40 Your answer [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55602-jun23-04-qp.webp?v=3)
![June 2023 Paper 2, question 7: The power dissipated across a 1 kΩ resistor is 20 W. What is the potential difference across the resistor? A 0.02 V B 50 V C 140 V D 20 000 V Your answer [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55602-jun23-07-qp.webp?v=3)
Q6(a)
The whole paper ↗![June 2023 Paper 3, question 6(a): Calculate the resistance, R, of the heater. R = Ω [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun23-06-a-qp.webp?v=3)
Q7(a)(i)
The whole paper ↗![June 2022 AS Paper 2, question 7(a)(i): Show that the maximum current in the cooker is less than 13 A. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun22-07-ai-qp.webp?v=3)
Q7(a)(ii)
The whole paper ↗![June 2022 AS Paper 2, question 7(a)(ii): The cost of 1 kW h of energy is 18p. Calculate the cost of using the cooker at maximum power for 30 minutes. cost = p [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-jun22-07-aii-qp.webp?v=3)
Q5(c)(ii)
The whole paper ↗![November 2021 AS Paper 2, question 5(c)(ii): Calculate the energy W dissipated in the variable resistor in 5.0 minutes. W = J [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-nov21-05-cii-qp.webp?v=3)
Q17(b)
The whole paper ↗
Q24(b)(i)
The whole paper ↗![November 2020 AS Paper 1, question 24(b)(i): A total output power 1.2 kW is required for a room. Calculate the number of mats required. number of mats = [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15601-nov20-24-bi-qp.webp?v=3)
Q7(a)(i)
The whole paper ↗![November 2020 AS Paper 2, question 7(a)(i): the resistance R of the heater R = Ω [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-nov20-07-ai-qp.webp?v=3)
Q7(b)
The whole paper ↗![November 2020 AS Paper 2, question 7(b): The cost of 1 kWh of energy is 16p. Calculate the cost of using the heater for 5.0 hours. cost = p [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15602-nov20-07-b-qp.webp?v=3)
Q3(b)(ii)
The whole paper ↗![June 2019 Paper 3, question 3(b)(ii): When the torch is switched on, the energy stored in the capacitor lights a 50 mW LED. Estimate the time for which the LED lights. time = s [1] Question 3 contin](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55603-jun19-03-bii-qp.webp?v=3)
All 33 questions on Power, as a list
- June 2025, Paper 2, Q21(d) (2 marks): A larger generator is used in a wind turbine to supply electricity to a house. The house is also connected to the 230 V mains supply. Turbine 230 V TV Lamp Hair
- June 2025, Paper 2, Q21(e) (1 mark): State the unit used to measure the electrical energy supplied to homes in the UK. [1]
- June 2025, Paper 3, Q1(d) (2 marks): Suggest two ways that the horizontal current may affect the atmosphere. 1 2 [2]
- June 2025, AS Paper 1, Q19 (1 mark): A current flows through a resistor. Which is a correct definition for the power dissipated in the resistor? A energy transferred from electrical energy to other
- June 2025, AS Paper 1, Q23(a) (3 marks): Calculate the percentage efficiency of the microwave oven. percentage efficiency = % [3]
- June 2024, AS Paper 2, Q7(b)(i) (1 mark): the energy E dissipated in r. E = J [1]
- June 2023, Paper 2, Q4 (1 mark): A 200 W heater is used for 90 minutes. The cost per kWh is 13 pence. How much did it cost to use the heater? A 3.9p B 39p C £2.34 D £23.40 Your answer [1]
- June 2023, Paper 2, Q7 (1 mark): The power dissipated across a 1 kΩ resistor is 20 W. What is the potential difference across the resistor? A 0.02 V B 50 V C 140 V D 20 000 V Your answer [1]
- June 2023, Paper 3, Q6(a) (2 marks): Calculate the resistance, R, of the heater. R = Ω [2]
- June 2022, AS Paper 2, Q7(a)(i) (2 marks): Show that the maximum current in the cooker is less than 13 A. [2]
- June 2022, AS Paper 2, Q7(a)(ii) (1 mark): The cost of 1 kW h of energy is 18p. Calculate the cost of using the cooker at maximum power for 30 minutes. cost = p [1]
- November 2021, Paper 2, Q3 (1 mark): The current in a lamp is 2.0 mA. The potential difference across the lamp is 6.0 V. What is the energy transfer in the lamp over a period of 3.0 hours? A 0.012
- November 2021, AS Paper 1, Q6 (1 mark): Four electrical circuits are shown below. A B C D All the resistors are identical. Each circuit is connected to the same power supply. Which circuit dissipates
- November 2021, AS Paper 2, Q5(c)(ii) (2 marks): Calculate the energy W dissipated in the variable resistor in 5.0 minutes. W = J [2]
- November 2020, Paper 2, Q14 (1 mark): The potential difference across a lamp is 2.5 V. The current in the lamp is 20 mA. What is the energy dissipated in the lamp in 3.0 hours? A 0.050 J B 0.15 J C
- November 2020, Paper 2, Q17(b) (2 marks): The LED is connected into a circuit, as shown below. 4.5 V R The battery has electromotive force (e.m.f.) 4.5 V and negligible internal resistance. The resistor
- November 2020, AS Paper 1, Q24(b)(i) (1 mark): A total output power 1.2 kW is required for a room. Calculate the number of mats required. number of mats = [1]
- November 2020, AS Paper 2, Q7(a)(i) (2 marks): the resistance R of the heater R = Ω [2]
- November 2020, AS Paper 2, Q7(b) (2 marks): The cost of 1 kWh of energy is 16p. Calculate the cost of using the heater for 5.0 hours. cost = p [2]
- June 2019, Paper 3, Q3(b)(ii) (1 mark): When the torch is switched on, the energy stored in the capacitor lights a 50 mW LED. Estimate the time for which the LED lights. time = s [1] Question 3 contin
- June 2019, AS Paper 1, Q7 (1 mark): A household is planning to change all their 60 W filament bulbs to 12 W LED bulbs. The household has a total of 10 bulbs. Each bulb will be used for about 2000
- June 2019, AS Paper 1, Q14 (1 mark): In a particle-accelerator electrons are accelerated through a potential difference of 120 kV. The electron beam current is 8.0 µA. What is the total energy tran
- June 2019, AS Paper 1, Q23(a)(ii) (2 marks): Calculate the ratio power dissipated in the internal resistance . total power supplied by cell ratio = [2]
- June 2019, AS Paper 2, Q4(a)(iv) (1 mark): Calculate the energy W dissipated in resistor Y in two minutes. W = J [1]
- June 2018, Paper 2, Q5 (1 mark): Three identical resistors X, Y and Z are connected to a power supply. X Y Z + – power supply The power dissipated in the resistor Z is 24 W. What is the power d
- June 2018, Paper 3, Q1(b)(i) (2 marks): Show that the resistance of the nichrome wire wound on the ceramic cylinder is 53 Ω. [2]
- June 2018, AS Paper 1, Q6 (1 mark): Two filament lamps X and Y are connected in series with a 16 V d.c. supply. The supply has negligible internal resistance. 16 V + – X Y Lamp X emits a power of
- June 2018, AS Paper 1, Q24(a)(i) (1 mark): Calculate the power dissipated by the component when V is +10.0 V. power = W [1]
- June 2017, AS Paper 1, Q12 (1 mark): Two filament lamps X and Y are connected in parallel to a supply. The power dissipated by lamp X is 24 W and the power dissipated by lamp Y is 6.0 W. The supply
- June 2017, AS Paper 2, Q4(a)(i) (1 mark): Show that the resistance of each heating element is about 15 Ω when the heater is operating at 230 V. [1]
- June 2017, AS Paper 2, Q4(b) (2 marks): The cost of 1 kW h of energy is 7.6 pence. Calculate the cost of using the three storage heaters between midnight and 7.00 am every night for one week. cost = £
- June 2016, AS Paper 1, Q9 (1 mark): A 9 V battery is connected to two resistors as shown. The terminals X and Y are connected to another circuit that draws a current of 1 mA. The current from the
- June 2016, AS Paper 1, Q19 (1 mark): A resistor of resistance R is connected in parallel with a resistor of resistance 2R. The combination of resistors is connected to a cell. R 2R power dissipated
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