Magnetic properties
Properties of magnets
Why some materials are magnetic
A magnetic material is made up of lots of very small
regions called domains. Each domain behaves like a
tiny bar magnet.
When a material is not
magnetised, the domains
are pointing in different
directions, but when
magnetised, they line up in
the same direction.
Making magnets
Iron and steel are magnetised by being close to a magnet.
 Iron is easy to magnetised, but when the magnet is
removed, the magnetism is lost immediately.
 Steel is harder to magnetise than iron, but it stays
magnetised for a while after the magnet is removed.
To make a permanent magnet,
You can stroke a piece of steel
bar repeatedly in the same
direction using the same pole
of a magnet.
Single stroke and double stroke
‘Seeing’ magnetic field patterns with a plotting
compass
A plotting compass is a very small compass used to
show the pattern of the magnetic field lines around a
bar magnet. The lines are not the field, but they show
us the general shape.
Class activity
Students in groups of two use the plotting
compasses provided to draw magnetic field lines.
When electric current flows through a wire, a magnetic
field is produced around the wire
 The magnetic
field lines around
the wire are in
concentric circles
 The magnetic
field gets weaker
as you get further
away from the
wire.