Explain how the behaviour of a magnetic compass is evidence that the core of the Earth must be magnetic.

Explain how the behaviour of a magnetic compass is evidence that the core of the Earth must be magnetic. sits within Magnetic fields in AQA GCSE Physics Unit 4.7 Magnetism and electromagnetism. A strong explanation names the exact magnetic context, then links the observation to field direction, current, force, coil turns, induced potential difference or transformer power as appropriate. For this objective, revise the keywords compass and use them as evidence rather than as isolated definitions. Keep the boundary precise: permanent magnets are not induced magnets, motors use current to produce force or motion, generators use motion or changing magnetic fields to induce a potential difference, and transformers compare primary and secondary coils. The distinctive exam cue is lo47cue313 fieldmap313 coilpath313 transformerlink313, which separates this learning objective from neighbouring transformer, motor-effect and magnetic-field objectives while preserving the official wording.