By: Austin Abt
Mrs. Crane 4th Grade Class
How does charge affect the
strength of homemade
magnets?
Hypothesis
 If there are more turns of copper wire wrapped around
the electromagnet, the magnet will be stronger. If
there are less turns of copper wire wrapped around the
electromagnet, the magnet will be weaker.
Facts
The bigger the battery the more magnetic it
becomes.
2. You can make a magnetic nail at home.
3. If you use a small battery the experiment will not
work.
4. The more times the copper wire is wrapped around
the nail the more magnetic the nail becomes.
1.
Experiment Materials and
Equipment
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Large iron nails (5)
Insulated copper wire
Wire cutters
Wire strippers
9-V battery
Iron filings
Paper cups (several)
Permanent marker
Kitchen scale
Lab notebook
Graph paper
Experiment Steps
1.
2.
3.
4.
5.
You will use four of the nails to make magnets, and save one
nail as a negative control. That means that you will not charge
the control magnet, and will see if it has any magnetic
properties on its own.
To make the four magnets, wrap insulated copper wire
clockwise around each nail, tightly, with different numbers of
wraps: 5, 10, 15, and 20.
Leave about 3 inches of loose wire at each end of the nail. Cut
the wire with wire cutters after you've wrapped each nail. You
now have four electromagnets.
Strip the last 1/2 inch of wire at each end with the wire
strippers.
Next, attach each electromagnet to the 9-V battery, one at a
time, to test the strength of each magnet. Record the
observations in your lab notebook.
Steps Continued
6.
7.
8.
9.
10.
11.
12.
You will want to connect each electromagnet to the battery in the same way. Wrap the
pointy end of the nail wire to the positive battery terminal, and the flat end of the nail
wire to the negative battery terminal.
To measure the strength of each magnet, use iron shavings. Pour your iron filings into
one of the paper cups. Dip the tip of one electromagnetic nail into a cup of iron
shavings and remove. What do you see? Record all observations in your lab notebook.
If there are any iron shavings stuck to the nail, move the nail over a clean cup to
remove them. While holding the nail and iron shavings over the cup, disconnect one
of the ends of wire from the battery terminal. What happens?
If there are any pieces of iron shavings still stuck on the magnet, brush them off into
the cup.
Label the cup with the type of electromagnet used (5, 10, 15, or 20 wraps) or with
"control," and set the cup aside.
Repeat steps 6–10 with the other magnets, and steps 7–10 with your un-magnetized
control nail.
Now you need to weigh each of your cups on the kitchen digital scale and write your
data in a data table, like the one shown below, in your lab notebook:
Controls and Variables
 Control:
 Copper wire
 Variable:
 Number of wire wraps
Observations
 Magnets can have different patterns of magnetic fields,
depending upon their shape.
 Because magnets are polar, you can arrange a series of
magnets to make a magnetic cushion.
 You can see the shape of the magnetic field by placing
a magnet on a piece of paper and dusting fine iron
shavings around the paper.
 A 9 volt battery will not pick up the metal but a D
battery will.
Data
Number of
Wraps
5
10
15
20
0
Length
¼
½
¾
Full
0
Magnetic
(Y/N)
Yes
Yes
Yes
Yes
No
Weight of
shavings
1 gram
2 grams
3 grams
4 grams
O
Analysis of Data
 The experiment tested my hypothesis. My hypothesis
was correct. More turns of copper wire wrapped
around the electromagnet picked up more iron
shavings. Less turns of copper wire wrapped around
the electromagnet picked up less iron shavings.
Therefore, more turns of copper wire makes a stronger
electromagnet.
 I changed the 9 volt battery to a D battery so the
electromagnet would be stronger. My new question is
why does a bigger battery pick up more iron shavings?
Conclusion
 More turns of copper wire wrapped around the
electromagnet picked up more iron shavings.
 Less turns of copper wire wrapped around the
electromagnet picked up less iron shavings.
References
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2.
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5.
http://www.sciencebuddies.org/science-fairprojects/project_ideas/Phys_p020.shtml?fave=no&isb=cmlkOj
QzMDQ1NjMsc2lkOjIscDox&from=TSW
Gagnon, S. (2005). How do I make an electromagnet? Thomas
Jefferson National Accelerator Facility, Office of Science
Education. Retrieved December 23, 2005, from
http://education.jlab.org/qa/electromagnet.html
KidsCanMakeIt.com (2001). Kids Can Make It: Electromagnet
Activity. Retrieved December 23, 2005, from
http://www.kidscanmakeit.com/SN0002.htm
www.newton.dep.anl.gov/newton/skasci/…/PHY105.HTM
www.school-for-champions.com/SCIENE/magnetism.htm