An Electromagnet Experiment by Stephen DeMeo

TITLE:
INVESTIGATING THE STRENGTH
OF AN ELECTROMAGNET

INVESTIGATORS AND THEIR ROLES
Stephen DeMeo & Ellen Stockbridge – Investigators
Lilly O’Heir – Student who reproduced the experiment

THE PHYSICAL EVENT
I am making an electromagnet by winding copper wire around an
iron nail, attaching the wire ends to a battery, and then seeing
how many paperclips it picks up.

MY PRIOR KNOWLEDGE ABOUT THE EVENT
We learned in class that an electromagnet involves electrons and
magnets. So how are these two things related?
When atoms charged with electrons are grouped and move
together, a current is formed. When this current is wound or
coiled around a substance, it can become magnetized.
Electromagnets are all about increasing the magnetic field of a
substance. Because all matter is made up of charged particles
which have a spin, there are magnetic fields for all matter.
Electromagnets help build up the strength of a magnetic field to a
value to show larger scale magnetization in two different ways.

MY PRIOR KNOWLEDGE ABOUT THE EVENT
1. The type of substance is important. Iron, cobalt, and
nickel work well because many of the electrons that spin
around the nucleus of these atoms spin in the same
direction, thus producing a larger magnetic field.
2. The wire holding the current must coil the substance
since using a single wire won't make a magnetic field
strong enough to pick up metal objects.
Once the current is turned off, the substance no longer acts
like a magnet.

OBSERVING, THINKING, AND CREATING
QUESTIONS ABOUT THE PHYSICAL EVENT
Observations: With multiple winds of wire around the nail, the nail
becomes magnetized; it attracts paper clips so it does indeed work;
there isn’t any “sensation” when it is close to or when it touches
my skin. The battery gets warm when the wires are connected.
Questions that come to mind: How many winds will pick up the
most paperclips. If I vary the winds of wire will I get a noticeable
difference in how many paperclips can be picked up. What would
happen if I used a bigger battery like a car battery?

RESEARCH QUESTION
How does increasing the turns of wire on a
homemade electromagnet (independent
variable) affect the strength of that
magnet (dependent variable)?

PREDICTION
The greater the number of coils, the greater
the strength of the magnet

1. Number of Coils of Wire: Independent Variable
2. Number of Paper clips picked up (magnetic strength):
Dependent Variable
3. How tightly the coils are wound (the spaces between
the coils)
4. The charge of the battery
5. The heat generated by the battery
INVENTORY AND CONTROL OF VARIABLES
Inventory of Variables

6. The size and weight of the paperclips
7. The area of the paperclip pile
8. The length of the wound coils
Inventory of Variables

1. Number of Coils of Wire: Use labels
2. Number of Paper clips picked up (magnetic strength):
Immediately record data in notebook
3. How tightly the coils are wound (the spaces between
the coils): Anchor the spool with a pencil and box; use
tape
4. The charge of the battery: Buy new; don’t wait long
between trials
Controlling these Variables

5. The heat generated by the battery: Disconnect quickly
after each trial
6. The size and weight of the paperclips: Don’t use large
clips; always use the same ones
7. The area of the pile of paperclips: Try to keep the
same circle size
8. The length of the wound coils: Try to keep them the
same length
Controlling these Variables

I originally thought a 9-volt battery would work well, but a
larger 6-volt lantern battery was much better. I found out that
the 6-volt battery could produce much more electrical current
for a longer time due to its larger electro-chemical cells within
the battery as compared to the smaller 9-volt.
I had old iron nails so I used them, but common nails sold in
hardware stores should work well also.
DESIGN DEVELOPMENT

DESIGN DEVELOPMENT: MATERIALS
● Wire
● enamel coated magnet wire 30 AWG
● This smaller gauge facilitates wrapping
the nail with a higher amount of turns
● Battery - 6v lantern battery
● Iron/Steel Nail
● I used 6 iron hand forged nails
● Use nails with as high of an iron content
as you can find! I had iron nails on hand,
but some steel nails will work as well.

DESIGN DEVELOPMENT: MATERIALS
● Sandpaper - 220 grit
● Alligator Clips
● Steel Paper Clips
● Tape, Scissors & Marker

AGREED TO DESIGN: PROCEDURE
Making the electromagnets
1. The first step is to set up the wire to start
wrapping the nails. It is important to properly set up
the wire so it does not coil on itself.
 GLP: I suggest creating a spool with a box & pencil
2. Wrap the nail with the wire at one end, leaving a
tail of about 4” of wire.
 GLP: Keep track of where you started your turns,
ensuring a correct count. Also, try and keep the turns
tight & neat.
Notes for
Good
Laboratory
Practices!

3. Wrap the nail until you have made 50 turns.
 GLP: If your nail is tapered, like mine, be sure to only
wrap along the end with a consistent width, to ensure each
turn is the same size. It is okay if the wire does not cover
the entire nail, as long as each nail has the same length
covered.
4. When done, trim the wire by cutting a
second 4” tail.
 GLP: Place a piece of masking tape on the end,
holding the end of the wire to prevent unraveling.

5. Lightly rub off the enamel on the ends of the
wire with sandpaper.
 GLP: Ensure not to rub off too hard/long, the
wire will snap off.
6. Repeat steps 1-5 with two other nails making
one with 100 turns and one with 150 turns.
 GLP: Be sure to label which is which, so you don’t
mix up each nail.

Testing the strength in terms of how many
paper clips can be picked up
7. Make a shallow pile of the paperclips on the
table.
8. Holding the nail by the wire ends, lower the
nail straight down into the pile of nails and pull
it back up slowly.
9. Move the nail off to the side and unclip the
nail from the battery, letting the paperclips fall.
 GLP: Make sure not to mix the piles of paper clips.

10. Count the amount of paper clips that the electromagnet held
and record. Repeat until a pattern emerges and stabilizes.
 GLP: If you leave the nail connected for too long it will get very hot, so
disconnect it when finished.
11. Remove the tape label during the paperclip test to ensure the
entire length of the nail was available to hold clips.
 GLP: Promptly replace the labels when you are done to make sure you
do not mix anything up!
12. Repeat for all three nails, record the data in a table.

COLLECTING RAW DATA: OBSERVATIONS
The wire tips and nail get warm when connected to the battery.

COLLECTING RAW DATA: MEASUREMENTS
NUMBER OF PAPERCLIPS HELD PER WIRE TURNS
Wire
Turns Paperclips held per 6 trials
50 8 4 5 8 5 4
100 17 18 20 19 14 21
150 22 24 18 22 26 24

DETERMINING THE BEST REPRESENTATIVE
VALUE FROM THE DATA SET
2 2
0 0
2
4 5 6 7 8
Frequency Distribution of Paperclips
picked up by the 50Turn
Electromagnet
Since the
distribution is
skewed right I
will choose the
median of 5 as
the best
representative
value

This distribution is
skewed left so I
will take the
median of 18 as
the best
representative
value
1
0 0
1 1 1 1 1
14 15 16 17 18 19 20 21
Electromagnet

Since this
distribution is
only slightly
skewed, I will
take the average
of 23 as the best
representative
value
1
0 0 0
2
0
2
0
1
18 19 20 21 22 23 24 25 26
Electromagnet

Wire
Turns Paperclips held
Best
Representative
Value of the Data
Set
50 8 4 5 8 5 4 5
100 17 18 20 19 14 21 18
150 22 24 18 22 26 24 23
VALUE OF THE DATA SET

PATTERN IDENTIFICATION
A linear pattern is a
possibility
0
5
10
15
20
25
30
0 50 100 150 200
Numbers
of
Paperclips
Held
Turns ofWire on Electromagnet
Numbers of Paperclips Held
vs.Turns of Wire

While this data shows a relationship, there are NOT
enough data points to feel confident in making a
conclusion that a linear trend exists.
We need more data!

 Let’s make 3 more magnets, filling in some
more data points on the trendline:
25, 75, and 125 turns
 Let’s also add 0 turns and see if the nail picks
up any paperclips. Perhaps the nail is slightly
magnetized.

COLLECTING MORE RAW DATA: MEASUREMENTS
0 0 0 0 0 0 0
25 3 2 3 2 2 3
75 11 12 12 13 11 12
125 18 19 20 19 23 24

Average is 2.5 so the
best representative
value could be 2 or
3. I will use my
rounding rules and
choose 2
0
3 3
0
1 2 3 4
Electromagnet

Since distribution is
fairly bell-shaped I
will take the average
of 12 as my best
representative value
0
2
3
1
0
10 11 12 13 14
Frequency Distribution of
Paperclips picked up by the 75
Turn Electromagnet

Since the
distribution is
skewed right I will
use the median of 20
as the best
representative value
1
2
1
0 0
1 1
18 19 20 21 22 23 24
Frequency Distribution of
Paperclips picked up by the 125
Turn Electromagnet

• In terms of center, most best representative values were
medians.
• In terms of shape, most of the frequency plots were skewed.
• In terms of spread, some of the diagrams were more spread
out than others.
• In terms of unusual features there were some gaps between
the bins.
Features of the Frequency Distribution Diagrams

COLLECTING ALL RAW DATA: MEASUREMENTS
Wire
Best Rep.
Value of the
Data Sets
0 0 0 0 0 0 0 0
25 3 2 3 2 2 3 2
50 8 4 5 8 5 4 5
75 11 12 12 13 11 12 12
100 17 18 20 19 14 21 18
125 18 19 20 19 23 24 20
150 22 24 18 22 26 24 23

0
5
10
15
20
25
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns ofWire
Paperclips Held vs.Turns of Wire

With Excel’s trendline function, I will try to find the best
trendline, linear or curved, that fits the data (bisects the
data points)

Power
A power
trendline
doesn’t fit the
data so well.
(zero point
can’t be
included)
y = 0.0205x1.4346
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
Numbers
of
Paperclips
Held
Numbers of Paperclips Held vs.Turns of Wire

Logarithmic
A logarithmic
trendline also
doesn’t fit the
data so well.
(zero point
can’t be
included)
y = 12.425ln(x) - 40.285
-5
0
5
10
15
20
25
0 20 40 60 80 100 120 140 160
Numbers
of
Paperclips
Held

Exponential
An exponential
trendline also
doesn’t fit the
data so well.
(zero point
cannot be
included)
y = 1.8662e0.0192x
0
5
10
15
20
25
30
35
0 20 40 60 80 100 120 140 160
Numbers
of
Paperclips
Held

Polynomial
When the zero
point is
included, the
polynomial
trendline fits
the data better
and resembles
a straight line
This is because
the x2 term is
very small.
y = -4E-05x2 + 0.1743x - 1.3333
-5
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns ofWire

Linear
A straight line
or linear
relationship
also fits the
data set well
(zero included)
y = 0.1686x - 1.2143
-5
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns ofWire

I will choose the linear plot over the polynomial without the zero
since more data points rest on the line. When the zero point is
included, the straight line and polynomial trendlines are almost
identical.
PATTERN MEANING

 We can describe the plot’s characteristics in terms of shape,
slope, strength and unusual features.
Shape:
Excel provides an equation for our linear trendline:
y = 0.1686x – 1.2143
Substituting our variables and rounding, our linear mathematical
model is:
Number of Paperclips Held
=
(0.17 paperclips/turns) (Wire Turns) – 1 paperclips
PATTERN MEANING

Slope and y-intercept:
Our equation says our slope is 0.17 paperclips held per 1 turn of
wire. Our slope means that an electromagnet consisting of a single
turn of wire should be able to hold 0.17 paper clips; more
realistically, it means that a 100 turn electromagnet should hold
17 paper clips. Incorporating the y-intercept would give us:
17 – 1 = 16 paperclips.
Strength: The linear relationship looks fair to good with some points
somewhat close to the line.
Unusual Features: none were observed
PATTERN MEANING

 Because the pattern of the data strongly suggests a straight
line pattern from 0 to 150 turns, It means that our two
variables, paperclips held and turns of wire, closely predict
each other in a specific proportional manner.
 Keeping the current of the battery constant, the turns of the
wire produces an electromagnet, with greater turns
producing greater magnetic strength.
PATTERN MEANING

PRELIMINARY ANSWER TO THE
RESEARCH QUESTION
Research Question:
How does increasing the turns of wire on a homemade
electromagnet affect the strength of that magnet?
As the amount of turns of wire increases, the number of
paper clips able to be held also increases in a
proportional, linear manner represented by the equation:
y = 0.17 paperclips held/turn – 1 paperclip, where y is
the number of paperclips held.

Good (and Ethical) Laboratory Practices
(emphasizes Reliability and Validity)
 We ensured GLP by following the protocol carefully and
mindfully. GLP notes were recorded in the procedure.
 Some important GLPs involved being consistent from
one trial to the next in relation to the winding of the
coils and the dispersion of the paper clips.

Repetition (emphasizes Reliability)
 For each condition we repeated the trials until:
• A pattern emerged
• Was reasonable with materials and time
• Was safe and careful (so the battery didn’t burn
out).
Peer Replication
 Lily O’Heir’s Data
Peer Review (emphasizes Validity)
 See the slide near the end of this presentation

Wire
Turns
Paperclips held per 6 trials Best Rep.Value
of the Data Set
0 0 0 0 0 0 0 0
25 18 14 14 15 13 16 15
50 21 18 27 22 28 24 23
75 28 39 28 31 33 23 30
100 29 30 37 25 32 42 32
125 37 28 32 40 29 41 34
150 42 38 43 29 34 35 37
Peer Replication: Lily O’Heir (emphasizes Reliability)

Peer Replication: Pattern Identification
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns of Wire

Power
A power
trendline seems
to fit the data
fairly well (zero
point cannot be
included)
y = 3.1702x0.4992
0
5
10
15
20
25
30
35
40
45
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns ofWire

Logarithmic
A log trendline
also seems to
fit the data
fairly well (zero
point cannot be
included)
y = 12.193ln(x) - 24.118
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns ofWire

Exponential
An exponential
trendline does
not fit the data
(zero point
cannot be
included)
y = 15.376e0.0066x
0
5
10
15
20
25
30
35
40
45
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns ofWire

Polynomial
A polynomial (2nd
order quadratic)
trendline with the
zero point
included also fits
the data well
y = -0.0019x2 + 0.5114x + 1.5476
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns of Wire

Linear
A linear
trendline is not
a good fit. y = 0.2257x + 7.5
0
5
10
15
20
25
30
35
40
45
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns of Wire

Peer Replication
The logarithmic and polynomial (2nd order quadratic) plots
seems to fit the data slightly better than the power, and
much better than the linear and exponential trendlines.
Therefore in terms of a mathematical equation, this peer
data does not support the main experiment’s linear
relationship. The reason is not known at this time.
What is common between the main and this peer experiment
is the positive qualitative trend of the data. In both, the
amount of paperclips increased as the number of turns of
wire increased.

Comparison with Material Standard
(emphasizes Validity)
This indicator was not possible since no standard was available.

Secondary Test (emphasizes Reliability)
 I created a secondary way of testing
the strength of our magnets by using
staples instead of paperclips.
 I followed the same exact procedure as
the paper clip test.
GLP: The staples need to be laid completely
flat, because they link on each other easily.

Secondary Test
 Observations:
The electromagnet picked up large bunches of staples in a
similar way to the paperclips.

Secondary Test: Raw Data
Turns Staples held Best Rep.
Value
0 0 0 0 0 0 0 0
25 4 5 5 4 4 3 4
50 9 5 7 5 4 6 6
75 13 15 14 14 17 15 15
100 16 15 17 17 18 18 17
125 26 25 30 35 26 27 28
150 40 32 37 45 38 32 37

Secondary Test: Pattern Identification
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Staples
Held
Turns of Wire
Staples held vs.Turns of Wire

Power
A power
trendline fits
the data
better (zero
point could
not be
included)
y = 0.0551x1.2767
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Staples
Held
Turns ofWire

Logrithmic
A log
trendline isn’t
very good
(zero point
could not be
included)
y = 17.415ln(x) - 57.32
-5
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Staples
Held
Turns ofWire

Exponential
An exponential
trendline is a bit
better than the
power trendline:
more data
points on the
line (zero point
could not be
included).
y = 2.7828e0.0181x
0
5
10
15
20
25
30
35
40
45
0 20 40 60 80 100 120 140 160
Number
of
Staples
Held
Turns ofWire

Polynomial
A quadratic
(2nd order
polynomial)
trendline is
much better.
y = 0.0011x2 + 0.0829x + 0.4048
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Staples
Held
Turns ofWire

Linear
A linear
trendline
doesn’t fit
the data very
well
y = 0.2429x - 2.9286
-5
0
5
10
15
20
25
30
35
40
0 20 40 60 80 100 120 140 160
Number
of
Staples
Held
Turns ofWire

The exponential and polynomial trendlines fit the data best.
This secondary test contradicts the main experiment (linear
trendline was best), as well as the replicated experiment
(polynomial and logarithmic trendlines).

Plots and Patterns (emphasizes Reliability)
Data that follows a specific pattern provides greater
confidence that the experiment is being conducted correctly.
 In the main experiment, three more data points and a zero
trial were added to our existing data set which confirmed
the initial pattern in the data.
 An overall increasing qualitative trend between the
variables was evident in the main, peer experiment, and in
the secondary test.

Conceptual & Historical Support (emphasizes Validity)
Only the main experiment is supported by the formula for
“Magnetic Field Strength” or “Magnetizing Force” represented by H.
H = I x N
L
Where:
N is the number of turns of the coil
I is the current flowing through the coil in amps from the battery
L is the length of the coil

Conceptual & Historical Support
The equation indicates that the greater the number of coils (N),
the greater the magnetic field strength (H). There is a direct
positive proportional relationship between N and H, if L and I are
constant. This relationship will give a linear plot.
This provides confidence for the linear relationship found in the
main experiment.

Conceptual & Historical Support
The first electromagnet was created by
William Sturgeon of England in 1825. It was a
horseshoe-shaped piece of iron that had 18
turns of bare copper wire wrapped around it.
Sturgeon used varnish to insulate the iron
metal from the copper coil (insulated wire
didn't exist yet).
An electromagnet
made in the 1800’s

External Data Sources (emphasizes Reliability)
I did not find any data sources that would support or
challenge my data.

Precision (emphasizes Reliability)
There are a few easy ways precision can be calculated
for the main experiment: range, average deviation, and
the mean absolute precision for straight lines.
Since I have a straight line trend for my main
experiment, I will use the mean absolute precision.
I will need to look at the x values (wire turns), the y
values (number of paperclips), as well as the equation
for the straight line graph calculated by Excel
(y=0.1686x–1.2143)

Precision: mean absolute precision (main experiment)
Making a table will help to keep track of our calculations. To get the Y predicted
value, the x value has to be used in the equation y(predicted)=0.1686x – 1.2143
X Value
(Wire Turns)
Yo Observed
(Paperclips)
Yp Predicted from
Trendline
(Paperclips)
Absolute
Difference
(Paperclips)
0 0 -1.2143 1.2143
25 2 3.0007 1.007
50 5 7.2157 2.2157
75 12 11.4307 0.5693
100 18 15.6457 2.3543
125 20 19.8607 0.1393
150 23 24.0757 1.0757
Sum 8.5756
Divide by number of data points 7
Mean absolute precision equals +1.2 = +1 paperclip

What does the mean absolute precision mean?
 This statistic measures how far off the data points are
to a linear center line (the bisecting line aka the
predicted trend that Excel has made).
 It is very much like average deviation in that it looks
at differences between experimental data points and
the best representative value, although in this case
the best representative value is not a single value but
collection of data points that corresponds to a best fit
straight line.

 The mean absolute precision was calculated to be +1
paperclip. In my opinion this is a good level of precision
for this experiment.
 The mean absolute precision can be represented by I-bars
on the Wire turns vs. paperclips held plot.

Precision: mean absolute precision as I-Bars
y = 0.1686x - 1.2143
-5
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns of Wire
Number of Paperclips Held vs. Turns of Wire

Precision: mean absolute precision as I-Bars
The I-bars
indicated that
there is
overlap
between 0
and 25 turns,
and 100 and
125 turns,
(making the
graph bigger
can help see
this)
y = 0.1686x - 1.2143
-5
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Held
Turns of Wire
overlap
overlap

Precision: Why overlap is important
 If you have overlap between data points, then there is no
difference.
 For instance, we want to know if the difference between 100
vs 125 turns of wire, produces a specific effect: If one
magnet will indeed pick up more paperclips than the other.
Why would this be important?
If you were a manufacturer of electromagnets why would you
make a 125 wire turn magnet if a 100 turn will pick up about
the same number of magnets? It doesn’t make economic
sense. Same too in science.

So what can we do when data points overlap?
 Because of overlap between 0 and 25 turns, and 100 and 125
turns, some data points are unnecessary to display. I will
remove the 0 turns and 100 turns since they do not produce
any effect on the dependent variable that is different than the
25 and 125 turns of wire.

Precision: Mean Absolute Precision (main experiment)
Now there is
no overlap.
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
Number
of
Paperclips
Turns of Wire

 If an uncertainty analysis will be performed, as it should, I
would recommend to hold off on removing data points when
using the precision indicator. As will be evident, precision
bars and error bars are related but different. Uncertainty in
my opinion is a more rigorous option for identifying if data
points should be removed due to overlap.

Accuracy
 There was no analysis of accuracy in this investigation
because we did not have a “known” value for comparison.

Redesign & What If Ideas
(emphasizes Validity & Reliability))
 Redesign: A redesign was made with the inclusion of three
more data points plus a zero point in order to determine if a
linear or curved relationship was present.
 What If Idea: As a future secondary test, the electromagnets
could be placed near a compass and the degree to which the
needle moves away from true north can be measured.
Check Calculations (emphasizes Reliability)
 The frequency distribution calculations were checked.

Confidence
Indicator
Relevant to
this
Experiment
Directly Verified
Preliminary
Result
Contradicted
Preliminary Result
or Inconclusive
Good Lab Practices ✓
Repetition ✓ ✓
Peer Support ✓ ✓
Secondary Test ✓ ✓
Comparison with a
Material Standard
Plots and Patterns ✓
Conceptual & Historical
Support
✓
External Data Sources
Precision ✓
Accuracy
Check Calculations ✓
Redesign & What If Ideas ✓
SUMMATIVE ANALYSIS OF THE CONFIDENCE
INDICATORS
The following
table shows
which of the
12 indicators
were used and
which ones
verified or did
not verify the
preliminary
result.

CONFIDENT ANSWER TO THE RESEARCH
QUESTION
 I have low confidence that a linear relationship exists in my
main experiment. This experiment could not be reproduced by
a peer and a secondary test was not supportive.
Research Question:

QUESTION
 I can confidently say that the data definitely supports a
positive relationship between the coil size of the
electromagnet and its strength as measured by the number
of paper clips that could be picked up, but what exactly that
quantitative relationship is, could not be determined by this
experiment.
Research Question:

QUESTION
 My prediction was correct, the more turns of wire the more
paperclips were picked up by the electromagnet.
Research Question:

INVESTIGATOR’S CONFIDENCE LEVEL IN THEIR
ANSWER
In a scale of 1 to 10, I give my confident result a 10 out of 10
that a positive qualitative relationship exists between the coil
size of the electromagnet and its strength as measured by the
number of paper clips that could be picked up, but what
exactly the relationship is, cannot be gleamed from this
experiment.

SIGNIFICANCE OF THE ANSWER IN LARGER
CONCEPTUAL AND SOCIAL CONTEXTS
We use electromagnets everyday. They are found in audio
speakers, electric powered saws, beverage mixers, and
hairdryers. And the future of transportation – electric cars –
rely on motors that are electromagnets.

The photo of the earth to the right shows
a reddish outer ring or core. This outer
core is made of liquid or molten iron, the
same element the nails in our experiment
are made out of.
The liquid iron of the outer core is so
dynamic, that the constant movement of
iron atoms creates a magnetic field. This
field protects us from damaging radiation
from the sun.

“The ancient Greeks and Chinese knew about naturally
magnetic stones called ‘lodestones’. These chunks of iron-rich
minerals may have been magnetized by lightning. The Chinese
discovered that they could make a needle magnetic by stroking
it against a lodestone, and that the needle would point north-
south.”
“Some animals, such as pigeons, bees, and salmon, can detect
the Earth's magnetic field and use it to navigate. Scientists
aren't sure how they do this, but these creatures seem to have
magnetic material in their bodies that acts like a compass.”

SUMMARY STATEMENT (ABSTRACT)
An experiment was performed to determine if the number
of coils around a rudimentary electromagnet would
increase its strength. Strength was assessed by the
number of metal paperclips that could be picked up. It was
determined that as the number of coils increased by
increments of 25 turns, the electromagnet picked up ever
increasing numbers of paperclips. This finding was
confirmed by a secondary test using metal staples and
replicated by a peer. While this qualitative trend was
apparent, a quantitative relationship was not confidently
determined.

ACKNOWLEDGEMENTS
This activity would not have possible if it wasn’t for Ellen
Stockbridge, an exceptional student of mine who is now teaching
earth science students in New York City.

REFERENCES
National Geographic Resource Library, Magnetism.
<https://www.nationalgeographic.org/encyclopedia/magnet
ism/>
Stack Exchange, Physics, “Do all things have a magnetic
field”. See
<https://physics.stackexchange.com/questions/187333/do-
all-the-things-have-a-magnetic-field/187338>
Wikipedia, “Electromagnet”.
<https://en.wikipedia.org/wiki/Electromagnet>
“The Electromagnet”. https://www.electronics-
tutorials.ws/electromagnetism/electromagnets.html

✓
Peer Review (emphasizes Validity)
Consensus was reached because a strong majority of
the class agreed with my or our confident result and
the parts that led to its construction.
Consensus was not reached because a majority of the
class disagreed with my or our confident result and
the parts that led to its construction.
Recommendations for Revision:

An Electromagnet Experiment by Stephen DeMeo

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