Coils, Coils, Coils!
Wrap a wire around practically anything and you’ve got a coil!
You have played with
and you may have made
but have you every made an electromagnet
To do this
you will need:
You can make a magnet
Wrap the rubber band around the battery.
Wrap the wire around
the bolt or nail,
at least 30 times.
Leave plenty of
wire at each end.
Sand each end
of the wire
Making an Electromagnet
Connect each end of the wire to the battery
by slipping them under the rubber band.
Make a coil with half the turns (15).
Does the electromagnet
pick up more or less paperclips
Count and record
the number of
you can pick up
with the nail.
You just made a magnet
Which end of the compass needle points to the head of the nail?
Does an electromagnet have a north and south pole?
NOW flip the wire connections
to the battery.
What happens to the poles
of the electromagnet.
Test it with your compass.
Which end of the compass needle points to the tip of the nail?
Test these for yourself.
You can weaken a temporary magnet by hitting it against a table or dropping it on the floor.
You can turn off your electromagnet by pulling one of the wires
away from the battery.
Sometimes the nail
Can you guess why?
Turning Electromagnets On and Off
Electromagnets are used to sort scrap metal.
Electromagnets can lift huge loads of iron and steel.
Detecting Magnetism in a Wire
You will need:
Place the wire
What happens to the compass needle
for each arrangement of the wire?
Briefly touch the other
end of the wire to the other battery terminal.
Hold one end
of the bare
wire firmly against
of the battery.
EXTRA: Place the wire next
to the compass and repeat 2-3.
Then try wrapping the wire
around the compass, as show.
How Does Electricity Create A Magnet?
Magnetic Field Around a Wire
Electrons, flowing in a wire, create a magnetic field around that wire.
Use the hand (compass) to observe the direction of this magnetic field around the wire.
Now click on the "current direction switching" rectangle to flip the current.
What happens to the direction of the magnetic field around the wire?
Click on the box at the bottom to demonstrate the right-hand rule for both directions.
Click on circles 1A, 2A or 3A, to add in one, two or three batteries in series.
When electrons flow
in a wire, what happens around the wire
What instrument can you use to detect a magnetic field around a wire
What did you use
to make a magnet
you could turn ON and OFF
As you increase
the number of turns
in a coil, what happens
to the electromagnet
a magnetic field forms around the wire
a battery, a wire and a nail
it gets stronger