Lesson T1.2.1

T1.2.1 Power ratings and energy use Quiz: KS3 Physics, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T1.2.1, Power ratings and energy use: 20 multiple choice questions for the KS3 Physics (National Curriculum), Unit 1: Energy, written with Revision Ninja.

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The 20 questions

  1. What is the SI unit of power?

    • Newton (N)
    • Pascal (Pa)
    • Joule (J)
    • Watt (W)

  2. What does a power rating of 2000 W mean?

    • 2000 watts per hour
    • 2000 J per second
    • 2000 seconds per joule
    • 2000 J total

  3. How many watts are in 1 kilowatt?

    • 100 W
    • 1000 W
    • 10 000 W
    • 10 W

  4. A 2 kW heater runs for 3 hours. How much energy is used?

    • 1.5 kWh
    • 5 kWh
    • 6 kWh
    • 0.67 kWh

  5. Which unit is used to measure electrical power?

    • Joule
    • Newton
    • Watt
    • Volt

  6. A 100 W bulb is left on for 10 hours. How much energy does it use?

    • 0.1 kWh
    • 1 kWh
    • 100 kWh
    • 10 kWh

  7. Energy transferred can be calculated using which formula?

    • Mass × speed
    • Force × area
    • Power × time
    • Power ÷ time

  8. Which unit is the kilowatt-hour a unit of?

    • Force
    • Energy
    • Power
    • Electric charge

  9. A 3 kW kettle runs for 30 minutes. How much energy does it use?

    • 0.17 kWh
    • 3.5 kWh
    • 6 kWh
    • 1.5 kWh

  10. How many joules are contained in 1 kWh?

    • 1000 J
    • 3600 J
    • 3 600 000 J
    • 60 000 J

  11. A 1 kW heater runs for 2 hours and a 2 kW heater runs for 1 hour. What is the total energy used?

    • 3 kWh
    • 4 kWh
    • 2 kWh
    • 6 kWh

  12. Which appliance transfers the most energy in one hour?

    • 1500 W hair dryer
    • 100 W TV
    • 300 W fan
    • 10 W LED lamp

  13. What happens when replacing a 60 W bulb with a 9 W LED?

    • Same energy transfer
    • Less energy per second
    • Zero energy used
    • More energy per second

  14. A microwave is rated 800 W. How many joules does it transfer in 10 seconds?

    • 8000 J
    • 800 J
    • 80 J
    • 80 000 J

  15. What is the scientific definition of power?

    • Energy transfer rate
    • Speed of a wave
    • Force multiplied by mass
    • Total energy stored

  16. A 2.5 kW kettle boils water in 3 minutes. How much energy is transferred?

    • 450 kJ
    • 4.5 MJ
    • 7.5 kJ
    • 125 kJ

  17. A 1200 W appliance is used for 5 minutes. How much energy does it transfer?

    • 240 kJ
    • 360 kJ
    • 36 kJ
    • 4 kJ

  18. Which uses more energy: a 2 kW heater for 4 hours or a 500 W computer for 12 hours?

    • Neither uses energy
    • 2 kW heater
    • 500 W computer
    • They use equal energy

  19. A 1500 W appliance uses 3 kWh of energy. For how long was it switched on?

    • 4.5 hours
    • 0.5 hours
    • 2 hours
    • 1.5 hours

  20. Why does a higher power rating mean faster energy transfer?

    • Higher voltage input
    • Lower resistance value
    • Less energy per second
    • More energy per second

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