MagnetismTopic Summary
Topic Summary: Magnetic Fields and Electromagnets
Part of Magnetic Fields — GCSE Physics
This topic summary covers Topic Summary: Magnetic Fields and Electromagnets within Magnetic Fields for GCSE Physics. Revise Magnetic Fields in Magnetism for GCSE Physics with 13 exam-style questions and 12 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 14 of 14 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 14 of 14
Practice
13 questions
Recall
12 flashcards
Topic Summary: Magnetic Fields and Electromagnets
Key Terms
- Magnetic field: region where magnetic material feels a force
- Permanent magnet: always magnetic (steel)
- Induced magnet: temporarily magnetic (iron)
- Electromagnet: current in coil creates magnetic field
- Magnetic flux density (B): field strength in Tesla (T)
Key Facts
- Field lines: N to S outside, arrows, closer = stronger, never cross
- Like poles repel; unlike poles attract
- Induced magnets ALWAYS attract to permanent magnets
- Soft iron core: loses magnetism when current stops
- Steel core: retains magnetism (hard magnetic material)
Electromagnet Strength
- Increase current (I)
- Increase number of turns/coils
- Add soft iron core
- Uses: cranes, MRI, relays, bells, loudspeakers
Exam Tips
- Always add arrows to field lines (N to S outside)
- Iron core NOT steel — must be able to switch off
- Induced magnets cannot be repelled
- Cutting a magnet makes two smaller magnets (no monopoles)