Data Sheet

Iron Core Rod
Rubber Grommet
1
2
3
4
You can turn on the switch to
pick up things with the electro-
magnet, then release the switch
to drop them. This is done with
large magnets at factories or
junk yards.
Project 48
Electromagnet Magnetic Field
1. Use the circuit from the preceding project, with the
iron core rod in the electromagnet (M3). An elec-
tronic magnet has a magnetic field just like an or-
dinary magnet. Hold your compass next to the
electromagnet and push the press switch (S2).
Move the compass all around the electromagnet
and watch where the compass points.
2. The magnetic field created by a magnet occurs in
a loop. You can see this using paper clips.
3. Remove the iron core rod from the electromagnet.
Now push the press switch again and try to pick
up things with the electromagnet. The attraction
is now very weak.
The iron core rod concentrated the magnetic ef-
fects of the electromagnet. You can use the com-
pass to see that electronic field is now much
weaker.
4. Materials made of iron concentrate their magnetic
effects at both ends. The center of the material
is magnetically neutral because the attraction
from each end is the same.
The magnetic field created by the electromagnet
works the same way. It is strongest at both ends
but neutral in the center. But the electromagnet
is hollow - so iron at one end will be sucked into
the middle.
Lay the electromagnet on its side. Hold the thin
rod next to the center hole and push the press
switch to suck it inside. Hold the switch and gently
pull the rod to see how much suction the electro-
magnet has.
The compass needle
maypoint opposite to how
it’s shown here, depend-
ing on how you connected
the jumper wires.
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