Chapter 6.20 Magnetism and electromagnetism - Summary Pearson Edexcel International GCSE (9-1) Physics Student Book - Physics

6 - 20 Magnetism and electromagnetism


Magnetism and magnetic materials
● Magnets attract objects made from magnetic materials, e.g.: iron, steel, nickel, cobalt
● Magnets cannot attract objects made from non-magnetic materials, e.g.: plastic,
wood, paper, rubber



Magnets
● ***Poles: strongest parts of a magnet
(SBA) where magnetic force is greatest
● Most magnets have 2 poles: N and S
● Magnetically hard (often permanent [retains its magnetism once magnetised]) - e.g.:
steel
Magnetically soft (often temporary [loses its magnetism easily]) - e.g.: iron
→ Electromagnets - has magnetic field when turned on; ALSO magnetically soft
(strength/direction of magnetic field can be changed very easily)
○ ***Like poles repel, unlike poles attract



Magnetic fields
● Around every magnet, there is a volume of space where magnetism can be detected
(the volume is called magnetic field)
(SBA) ***Region where magnetic force exerted
● Normally magnetic fields cannot be seen, but their shapes can be shown by using
iron filings/plotting compasses, discovering something about its strength and
direction
○




■ ***Magnetic field lines from N to S
● ***Magnetic field line: line showing direction of magnetic
force\field




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, Overlapping magnetic fields***
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