Coils and nails:
an experiment for electricity projects
Background
Electricity projects offered by Good-Science-Fair-Projects.com would not be complete without one on electro-magnetism.
But let me give you a quick history lesson about this subject. In 1820, a scientist named Hans Christian Oersted noticed that a magnet was affected by an electric current flowing in a wire.
Being the good scientist that he was, he set up one of his own little electricity projects - an experiment to prove his hypothesis. He placed a wire with a current flowing in it over a compass, and hey presto, the compass needle moved away from north. When he switched the current off again, the compass needle returned to north.
Before you get going with the main experiment, you can try Hans' one out. All you need is some flexiwire, a compass and a couple of batteries. Hook the wires up to the batteries (you really just have to hold the bare ends of the wires on the positive and negatives ends of the battery) and then lie the wire over the compass.
This can be an extra touch for your display – what it does is shows that a wire with a current in it has a magnetic field. Right, having established that, on to the main experiment...
Let's do science...
The Experiment
So we have established that a wire with an electric current flowing in it will have a magnetic field. Now we need to use that field to magnetize a piece of steel and abracadabra! we have an instant magnet...
The Aim
To create a magnet using the magnetic field created when electricity flows in a wire.
Equipment Needed
3 meters of flexiwire
A six inch steel nail.
Batteries (scientifically called cells), lots of them as you will probably run them down quickly once you realize the fun an electro-magnet can be.
Insulation tape.
Metal objects to test your electro-magnet on.
Method
Separate the flexiwire so that you have 2 strands of wire.
Wind one of the strands of flexiwire around the nail as many times as you can, and then go over it again until you have multiple layers of wire around the nail– this is called a solenoid.
Leave the two ends of the wire long enough (about 15cm each) so you can easily attach them to the cell (or battery of cells of you put more than one together).
Use the insulation tape to tape the ends onto the nail so that the wire does not unwind.
Attach each end to the cell/s by either just getting someone to hold the ends of wire on each of the terminals of the battery, or by attaching them to the terminals using either cellotape.
Try and pick up some metal objects with the nail.
Switch off the current in the solenoid by removing at least one of the ends of the wire from a terminal of the cell.
Try and pick up the metal objects again.
Results
Once the current was flowing through the wire, the nail could pick up those metal objects that have magnetic properties (such as those with iron in them). The photo shows the electro-magnet that I made picking up a paper clip.
Once the current was switched off, the nail ... (This is one of those electricity projects where some thought, your thought, is needed. It is up to you to fill in the blank – report exactly what happened once there was no longer current flowing in the solenoid.)
The Conclusion
The magnetic field surrounding a wire with a electric current flowing in it, caused the nail (the metal core) to become magnetized.Br>
Here is some thinking for you to do to make this one of those electricity projects that has the edge:
What will affect the strength of the magnet? Do some extra experiments of your own to find out.
Click here for another one of Good-Science-Fair-Projects.com's electricity projects.
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