Lesson T5.3.2

T5.3.2 Earth's magnetism and compasses Quiz: KS3 Physics, Unit 5

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson T5.3.2, Earth's magnetism and compasses: 20 multiple choice questions for the KS3 Physics (National Curriculum), Unit 5: Electricity and magnetism, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. Earth's magnetic field behaves most like the field of:

    • A giant bar magnet
    • A rotating electric fan
    • A high-voltage power cable
    • A large electric charge

  2. Why does a compass needle point roughly north?

    • Earth's magnetic field pulls the needle into line
    • The Sun's heat pushes the needle north
    • The needle is heavier at its north end
    • Gravity pulls the needle towards the pole

  3. Earth's geographic north pole lies close to which magnetic pole?

    • The Moon's magnetic pole
    • The Sun's magnetic pole
    • Earth's magnetic south pole
    • Earth's magnetic north pole

  4. Why does a compass needle stop swinging?

    • Air resistance stops the needle instantly, before it can settle
    • Gravity pins the needle firmly down onto the surface it rests on
    • It runs out of magnetic energy and gradually loses its magnetism
    • It lines up with the magnetic field and comes to rest

  5. What is thought to produce Earth's magnetic field?

    • Magnets buried under the oceans
    • Electric currents flowing through the atmosphere
    • Heat from the Sun passing through the crust
    • Movement of molten iron in Earth's outer core

  6. Which use of compasses depends on Earth's magnetism?

    • Measuring rainfall
    • Measuring the speed of sound
    • Measuring air pressure
    • Navigation on land and at sea

  7. Why might a compass give a wrong reading near an iron girder or steel pipe?

    • Steel blocks Earth's gravity from pulling the needle into line
    • Steel makes the needle become hotter and therefore much heavier
    • Steel stops the needle from becoming magnetised by Earth's field
    • The steel is magnetised and has its own field that disturbs the needle

  8. A compass is placed near a strong bar magnet. Why does the needle no longer point north?

    • The magnet removes all magnetism from Earth in that local area
    • The magnet's field is stronger than Earth's and turns the needle
    • The needle becomes electrically charged by the nearby magnet's field
    • The needle is pulled down towards the bench by the magnet's weight

  9. Which statement about Earth's magnetic field is correct?

    • It is produced by the gravity of the Moon acting on the oceans
    • It exists only at the equator and nowhere else on the globe
    • It helps shield Earth from some charged particles from the Sun
    • It is the same strength everywhere on the surface of the globe

  10. Why is a magnetic compass useful for navigation even when the Sun cannot be seen?

    • The needle is warmed by sunlight, which keeps it steady in the dark
    • The needle glows faintly in the dark so it can be read at night
    • Earth's magnetic field works day and night, in any weather
    • The needle is powered by a small battery hidden inside the case

  11. Which of these can a compass detect?

    • The mass of the Moon
    • The temperature of the air
    • Electric charge on a balloon
    • A nearby magnet's field

  12. Which is the best description of a compass needle?

    • A piece of iron that is always heavier at one end
    • A small battery connected to a wire
    • A thin strip of plastic with static charge on it
    • A small magnet balanced so that it can turn freely

  13. Compasses are used with maps mainly to:

    • Measure the height of a hill
    • Measure the speed of a car
    • Find the direction of north
    • Work out the local temperature

  14. Which pole of Earth's magnet is closest to the geographic south pole?

    • Its magnetic south pole
    • Its magnetic north pole
    • Its magnetic equator
    • Neither, because the Sun is there

  15. Which of these would NOT disturb a compass needle?

    • A bar magnet
    • A wooden table
    • A nearby iron nail
    • A steel key

  16. A compass is placed in a region with no magnet nearby. What determines the direction of its needle?

    • Earth's magnetic field
    • Air currents in the room
    • Electric charge in the room
    • The Moon's gravity

  17. Why must the needle of a compass be free to turn?

    • So it can line up with the magnetic field
    • So it can pick up iron filings from the surface
    • So it can be heated gently by the warmth of the Sun
    • So it can store electric charge for later use

  18. Which phenomenon is linked to Earth's magnetic field and charged particles from the Sun?

    • Rainbows that form after rain showers
    • Thunderstorms that build over warm land
    • Earthquakes along faults in the crust
    • Auroras, the northern and southern lights

  19. A walker's compass swings wildly in a forest. What is the best action?

    • Put the compass in a plastic bag
    • Shake the compass hard to reset it
    • Move away from metal objects and try again
    • Warm the compass with a lighter

  20. What is the name of the part of a compass that turns to show direction?

    • The base plate
    • The needle
    • The dial
    • The glass cover

All KS3 Physics quizzes