Download Click here for experiment - Environmental Learning Center

4th
Experimenting with Electromagnets
grade Unit: The Practice of Science and Physical Science
Sarah Rhodes-Ondi, ELC Naturalist
Electricity and Magnetism have many practical uses in everyday life. Can
you imagine watching TV at night without electricity? You wouldn’t be able to
turn on the TV or a light bulb at night. Electromagnets are very useful because
they stop working when the current source is turned off. Telephones, school
bells, tape recorders and automatic doors all use electromagnets.
How do they work? Let’s start with the basics. Atoms are made up of
protons, neutrons and electrons. The protons are positively charged, the
electrons are negatively charged and the neutrons are neutral (no charge). The
nucleus, center of the atom, is made up of protons and neutrons. The electrons
travel around the nucleus in shells. A magnetic field is formed when electrons
spin in the same direction around a nucleus
(http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html). If they spin in
different directions they cancel each other out. Most materials are not magnetic
because the electrons spin constantly in many directions and cancel each-other
out. Magnets have two polls; a north and a south pole. The magnetic field
travels from north to south. An electromagnet is a magnet that is formed due to
an electric current. How strong are the magnetic fields formed by an
electromagnet? Let’s find out.
Steps of the Scientific Method
1. State Problem
 What question are you trying to answer by doing this experiment?
 Write “Does an electromagnet pick up objects the same distance
away as a standard magnet?” in the spot labeled #1 on your Lab
Form.
2. Do Research
 Read about your topic in books. Talk to experts. Observe the real
world. Become the expert!
 Write anything you learn that will help you plan and explain your
experiment on #2 on the Lab Form.
3. State Hypothesis
 Based on your research, make an educated guess about what will
happen when you do your experiment using what you learned from
your research (#3 Lab Form). This should be written with a
prediction and not in question form.
4. Design Experiment
 Independent Variable: What factor (treatment) are you testing?
Hint: Strength of magnetic field.
 Dependent Variable: What will you measure or observe? Hint:
distance away from object magnet can attract object. Can you
think of something else you could measure?
 Control: What are you comparing the electromagnet to? Hint:
standard magnet.
 Replication: How many replicates will you do? Scientists run a
minimum of 5 in case they make a mistake. If you were doing this
experiment at home you would need to make 5 different
electromagnets and use 5 standard magnets. Hint: Each group is
running 1 replicate of this experiment.
 Record all on Lab Form #4.
5. List Materials
 Recorded on Lab Form #5.
 3 ft of 22 gauge copper wire (for each electromagnet)
 1 AA battery (for each electromagnet)
 3.5’’ non-galvanized nail (for each electromagnet)
 Electrical Tape
 Scissors
 Ruler
 Standard bar magnets 3/8’’ * 3/8’’ * 1-7/8‘’
 Large Paper Clips
 Large Insulated Paper Clips
6. Test Hypothesis
 Procedure: Do experiment!
o Record the list of steps below on Lab Form #6.
o Create the electromagnet
1. Wrap 40 neat coils around the nail using the middle
portion of the wire. Make sure at least ½’’ of the nail is
exposed from the point on the pointy end of the nail.
2. Expose one inch of the copper on the ends of the wire
using the scissors.
3. Attach ends of the wire to either side of the battery with
a small piece of electrical tape. Caution: Copper wire
will feel hot to touch! Avoid touching wire when on
battery! Pick up electromagnet with battery.
o Place the standard magnet at a distance (ex: 2’’, 1’’, ½,’’ 0’’)
from the non-insulated paperclip. Record observations.
Make note of furthest measurement where magnet attracts
the object to it.
o Place the electromagnet at all of the same distances as did
with the standard magnet. Record observations at each
distance.
o Record data on Lab Form #7
7. Analyze Results
 What is the most common distance that each group of students
attracted the objects with either magnet? Calculate the mean
distance the paper clips are attracted to the magnets for both the
electromagnet and standard magnet.
 Graph your results.
 Record on Lab Form #8
8. Draw Conclusions (Write answers on Lab Form #9)
 Does your data support your hypothesis? Which magnet would be
better to pick up something further away? Why?
 What is an advantage of using either type of magnet?

What did you learn?

How could you change the experiment next time you run it?

Try this experiment with the insulated paperclip. What do you
observe? Do you have the same results?

At home try wrapping the copper wire around a rolled piece of
aluminum foil. Is a magnet still formed? Can you think of any other
materials to try?
Lab Form
1. State Problem
2. Research
3. Hypothesis
4. Design Experiment
5. Materials










6. Test Hypothesis
7. Data Collection (Ask each group for their results to
fill in a-e.)
a.
b.
c.
d.

Observations:

Furthest Distance Pick up Paper Clip
Electromagnet
Standard Magnet
e.
Calculate the Mean Distance for Each Magnet Type
_____+_____+_____+_____+_____ =
=
5
_____+_____+_____+_____+_____ =
=
5
8. Analyze Results
9. Draw Conclusions
References
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfie.html#c1
http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
http://ktcatspost.blogspot.com/2007/01/homemade-electromagnet-project.html
http://van.physics.illinois.edu/qa/listing.php?id=2339
http://education.jlab.org/beamsactivity/6thgrade/magnetsandelectromagnets/over
view.html
Note to teachers:
Explanation
The battery is the electric current source, copper is a conductor. By wrapping the
insulated copper wire around the nail and connecting it to the battery, the nail
becomes magnetic because charge from the current is transferred to the nail.
The nail stays magnetized when removed from the current source, so it is
important to use different nails each time the kids do the experiment.
Class Project Extensions


Vary the number of coils. The greater the number of coils, the stronger
the field.
Test other materials to see if can make a current or not.
Sunshine State Standards
 Benchmarks on next page
 Plan and conduct an experiment related to electricity and magnetism.
 Answers how electricity and magnetism are used everyday.
Benchmark
Science
 SC.4.N.1.1

SC.4.N.1.4

SC.4.N.1.5

SC.4.N.1.6

SC.4.N.1.8

SC.4.P.8.1

SC.4.P.8.4




Mathematics

Description
MAFS.4.NF.2.3




Raise questions about the natural world, use appropriate
reference materials that support understanding to obtain
information (identifying the source), conduct both individual
and team investigations through free exploration and
systematic investigations, and generate appropriate
explanations based on those explorations. Cognitive
Complexity: High
Attempt reasonable answers to scientific questions and cite
evidence in support. Cognitive Complexity: High
Compare the methods and results of investigations done by
other classmates. Cognitive Complexity: Moderate
Keep records that describe observations made, carefully
distinguishing actual observations from ideas and
inferences about the observations. Cognitive Complexity:
High
Recognize that science involves creativity in designing
experiments. Cognitive Complexity: Moderate
Measure and compare objects and materials based on their
physical properties including: mass, shape, volume, color,
hardness, texture, odor, taste, attraction to magnets.
Investigate and describe that magnets can attract magnetic
materials and attract and repel other magnets. Cognitive
Complexity: High
Understand a fraction a/b with a>b as a sum of fractions
1/b. a. Understand addition and subtraction of fractions as
joining and separating parts of the same hole.