15/1/25
Investigating
Electromagnets
• We know that to make an electromagnet, we need a coil of
wire, a magnetic material core inside the coil, an electric
current flowing in the coil. These are also the three factors
that will affect the strength of an electromagnet:
(a) The number of turns in a coil: the more turns, the stronger
the electromagnet. (b) The material of the core: iron and some types of steel as
the core make the strongest electromagnets.
(c) The current in the coil: the greater the current, the
stronger the electromagnet.
• Soft iron cores are the most ideal. They aren't literally soft, it
is just the term used for iron that is easily magnetised and
demagnetised.
• The strength of an electromagnet can be measured by the
force that the electromagnet exerts on a magnetic material.
An easy way to do this is to see how many magnetic objects
the electromagnet can lift and hold.