Elenco Upgrade Kit SC300 to SC750 - Manual (Page 135)

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Project #660
OBJECTIVE: To learn how electricity and magnetism are
related.
Electromagnetism
Project #661 Electromagnetism
& Compass
You need a compass for this project (not included). Use the circuit
from project #660, with the iron core rod in the electromagnet (M3).
You may want to use the slide switch (S1) in place of the press switch
(S2), but only turn it on as needed or you will quickly drain your
batteries.
Turn on the slide switch and move the compass around near the edges
of the electromagnet, it will point toward ends of the iron core rod. By
slowly moving the compass around the electromagnet, you can see
the flow of its magnetic field.
The earth has a similar magnetic field, due to its iron core. A compass
points north because it is attracted to this magnetic field. The
electromagnet creates its own magnetic field, and attracts the
compass in a similar way.
Put the iron core rod into the electromagnet (M3). Press the press switch (S2)
and place the electromagnet (M3) near some iron objects like a refrigerator or
a hammer, it will be attracted to them. You can use it to pick up iron objects,
such as nails.
Electricity and magnetism are closely related, and an electric current flowing in
a coil of wire has a magnetic field just like a normal magnet. Placing an iron
rod through the coil magnifies this magnetic field. Notice that when the
electromagnet is attracted to an iron object, its attraction is strongest at the
ends of the iron core rod. If you remove the iron core rod from the
electromagnet then its magnetic properties are greatly reduced – try this:
If you place the electromagnet upside down under a large object like a table,
you can suspend it there. Be careful though, since it will fall when you release
the press switch.
You can use this circuit to see which things are made of iron. Other metals like
copper or aluminum will not be attracted to the electromagnet.
Magnetic Field
Compass
OBJECTIVE: To learn how electricity and magnetism are
related.