Elenco Snaptricity&reg - Manual (Page 61)

Description
Any electric current flowing in a wire has a
magnetic field, but it is usually very small. An
electromagnet creates a noticeable magnetic
field by looping the wire very many times to
concentrate the magnetic field from it.
Note: The magnetic field produced by the wire is
very small. If the compass needle does not move,
check your batteries (B3), make sure you are not
close to any iron objects, and make sure the red
jumper is far from the compass.
-60-
Wire magnet Project #51
Build the circuit as shown. This circuit works best
with new alkaline batteries.
Notes:
1. Place the red jumper wire near the 6-snap wire
at the bottom of the circuit. Keep it as far away
from the compass as you can.
2. The 5-snap wire is connected on level 4 on the
left side and at level 3 on the right side, over the
compass. Make sure it is securely snapped.
Assembly
Set the slide switches (S5) so that the lamps (L4)
are on. While watching the compass, flip both
slide switches (reversing the current through the
lamps). You should see the compass needle
move a little - indicating a change in the magnetic
field from the wire.
Operation
Educational Corner:
Electric Paths
In 1820 Hans Christian Oersted of
Denmark noticed that an electric
current affects a compass needle. This
was the discovery of electromagnetism!