Lesson 3.1.3

3.1.3 Electrical power and energy Quiz: Pearson Edexcel Physics, Unit 3

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.1.3, Electrical power and energy: 20 multiple choice questions for the Pearson Edexcel Physics (9PH0), Unit 3: Electric Circuits, written with Revision Ninja.

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The 20 questions

  1. The power dissipated in a component is given by:

    • P = VI
    • P = I/V
    • P = V/I
    • P = V + I

  2. Electrical energy transferred in a component is given by:

    • E = V/It
    • E = I^2 t/V
    • E = V + It
    • E = VIt

  3. Which pair of expressions for power is equivalent to P = VI for a resistor?

    • P = I/R and P = V/R
    • P = IR and P = VR
    • P = I^2 R and P = V^2/R
    • P = I^2/R and P = V^2 R

  4. A resistor dissipates 6.0 W when the potential difference across it is 3.0 V. What is the current?

    • 18 A
    • 2.0 A
    • 0.50 A
    • 9.0 A

  5. A lamp is connected to 230 V and carries a current of 0.50 A. What is its power?

    • 460 W
    • 57.5 W
    • 230 W
    • 115 W

  6. A heater has a power rating of 2.0 kW and operates for 30 minutes. How much energy is transferred in kilowatt-hours?

    • 3.6 kWh
    • 1.0 kWh
    • 0.5 kWh
    • 2.0 kWh

  7. A 10 ohm resistor carries a current of 2.0 A. What power is dissipated in it?

    • 5.0 W
    • 40 W
    • 80 W
    • 20 W

  8. A 6.0 ohm resistor is connected across a 12 V supply. What power is dissipated?

    • 72 W
    • 0.50 W
    • 24 W
    • 2.0 W

  9. A 100 W bulb operates for 10 hours. Given that 1 kWh costs 15 p, what is the cost of running it?

    • 15 p
    • 150 p
    • 100 p
    • 1.5 p

  10. A lamp of resistance 4.0 ohm is connected across a 12 V supply for 10 s. How much energy is transferred?

    • 1440 J
    • 360 J
    • 36 J
    • 90 J

  11. A heating element dissipates 500 W when connected to a 230 V supply. What is its resistance?

    • 0.46 ohm
    • 106 ohm
    • 460 ohm
    • 2.2 ohm

  12. A fixed resistor has its current halved. By what factor does the power dissipated in it change?

    • It stays the same.
    • It falls by a factor of 2.
    • It falls by a factor of 8.
    • It falls by a factor of 4.

  13. A 2.0 A current flows through a 5.0 ohm resistor for 4.0 s. How much energy is transferred?

    • 20 J
    • 160 J
    • 80 J
    • 40 J

  14. Why are power lines operated at high voltage when transmitting electrical energy over long distances?

    • A higher voltage reduces the power transmitted.
    • A higher voltage reduces the current for the same power, so the I^2R losses in the cables are smaller.
    • A higher voltage makes the cables superconducting.
    • A higher voltage increases the current and so reduces the resistance of the cables.

  15. A 60 W bulb runs at 230 V for 4.0 hours. What is the energy transferred in kilowatt-hours?

    • 0.24 kWh
    • 0.060 kWh
    • 2.4 kWh
    • 15 kWh

  16. A kettle operating at 2.0 kW is used for 5.0 minutes. How much energy does it transfer?

    • 24 kJ
    • 600 kJ
    • 2.4 MJ
    • 10 kJ

  17. A device operates at 12 V and draws a current of 0.50 A. How much energy is transferred in 60 s?

    • 6.0 J
    • 720 J
    • 12 J
    • 360 J

  18. A 9.0 V battery drives a current of 2.0 A through a resistor for 30 s. How much power is dissipated?

    • 36 W
    • 4.5 W
    • 18 W
    • 270 W

  19. A resistor is changed so its resistance doubles, while the current through it stays the same. What happens to the power dissipated?

    • It doubles.
    • It halves.
    • It quadruples.
    • It stays the same.

  20. A cell of emf 6.0 V supplies a current of 0.40 A to a resistor for 2.0 minutes. What is the energy dissipated?

    • 2.4 J
    • 288 J
    • 144 J
    • 1.2 kJ

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