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Is your science fair coming up, but you’re still not sure what to present for it? Trying to find a last minute idea without breaking the bank can be really frustrating but one simple tool- magnets can give you a few ideas!
This is experiment #2 in a 3 part series of fun, simple, inexpensive projects that will wow your judges at the science fair.
Did you know you can create your own electromagnet? You can then use them to show the effect of electromagnets on a compass by comparing their magnetic fields.
Electromagnets work as magnets when electrical current is flowing through them. To make one – begin with a large nail, wrap some insulated wire around it and then connect the ends to a battery. Place a compass nearby it and see what happens. How close does the compass have to be to see an effect?
Remember to select ONE variable, predict the effect of that variable, make a change or a range of changes to just that variable, and record your results. The variables in this experiment are the wire, the nail, the battery and a compass or iron filings or small metal objects like paperclips.
Think about the wire: how might different types of wire affect the strength of the electromagnet?
Think about the coil: what happens with the magnetic field when you coil the wire more around the nail? How about if you coil it less? So what effect does the amount of coiled wire have on the electromagnet’s strength as a magnet? If you select this question, be careful not to introduce changes to two variables. You are either exploring the tightness of the coil (using the same amount of wire) or you are exploring the amount of wire (with the same degree of tightness).
Think about the nail: how might different size nails affect the strength of the electromagnet?
Think about the battery: how might different types or brands of batteries affect the strength of the electromagnet?
If you want, you can use iron fillings on a paper plate or napkin and place your electromagnet beneath it. The fillings should arrange themselves around the magnetic field. You can use your these results to create a visual presentation for the science fair.
Problem to solve: How might you measure “strength” so that you have a quantitative dependent variable? (HINT: the closer an object has to be to observe an effect of the electromagnet, the weaker the electromagnet is). Are there other measurements you could make?
Bruce Utsler is a freelance blogger and science enthusiast. He is currently studying to become an X-ray technician. He is an expert with magnets, particularly neodymimium magnets. When he isn’t busy studying or experimenting, Bruce likes to hit the streets with his longboard. –