Project 49
Electromagnet Tower
Coils of wire store energy in a magnetic field,
while static electricity stores energy in an elec-
tric charge across a material (an electric field).
Magnets concentrate their magnetic effects at
both ends. The magnetic field is strongest at
both ends but neutral in the center, because
the attraction from each end is the same. But
the electromagnet is hollow - so iron at one
end will be sucked into the middle.
The magnetic field produced by the electro-
magnet has direction just like a normal mag-
net. Opposite ends of magnets attract, while
like ends repel each other.
Find two magnets in your home. Try putting
them together, then flip one around. They will
attract one way but repel the other way.
Build the circuit as shown and drop the thin rod into
the electromagnet (M3). Push the press switch (S2)
several times. The thin rod gets sucked into the
electromagnet and can be suspended there, or you
can bounce it up and down.
When you push the press switch, the thin rod gets
sucked up and wiggles up and down until settling
in position just below center. Measure how high
you get the thin rod to go, then try with old and
brand new batteries. Remove a 1-snap from under
each side of the electromagnet, then see how high
the thin rod will go.
Part B:
With the switch pressed and the thin rod
suspended in mid-air, hold the magnet near the
thin rod. Notice that the red (N) side of the magnet
repels the thin rod but the black (S) side attracts it.
Note:
the magnet poles may be opposite of how it’s
shown here, depending on how you connected the
electromagnet (M3).
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