Factors affecting the Strength of an Electromagnet · PDF fileFactors affecting the Strength...
Transcript of Factors affecting the Strength of an Electromagnet · PDF fileFactors affecting the Strength...
Factors affecting the Strength of an Electromagnet Grade 11 Physics 11/25/2014 Fairview International School Qanita Dhanani 11R
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 1
Qanita Malik Dhanani
Mr. Marlon A. Uson
Physics
26 November 2014
The effect of Voltage on the strength of an Electromagnet
I. Introduction
A. Background Information
Essentially, an electromagnet is a magnet which runs on electricity due to the fact that a
magnetic field is produced by the electric current supplied to it. When the current is
stopped, the magnetic field is cancelled as there is no current flow arranging the atoms in
the core which produces the magnetic field. The most crucial components of an
electromagnetic circuit are a solenoid, which is a coil of insulated wire, a magnet either with
an iron, cobalt or nickel core, a power supply and wires to join the circuit together. Cores
magnets can only be made from iron, cobalt and/or nickel due to only them having
magnetic properties. Further, their alloys such as steel are able to be attracted towards this
magnetic field. The three metals which conduct magnetism are called Ferro magnets due to
their magnetic properties.
Electromagnetism has science underpinnings behind them. When wanting to create an
electromagnetic circuit first, the magnet is to be covered into conductive wire, usually made
out of copper and later this wire should be covered with an insulator to ensure safety. The
wrapping of the wire around the magnet is known as a solenoid and this leads to the
magnetic field radiating away. Before the solenoid is electrified, it arranges particle into a
particular way. An observation made is that materials with high permeability ensure high
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 2
conduction towards a magnetic field. When the atoms are in motion and all facing towards
the same direction, there is a stronger magnetic field present. Domains are regions of small
populations of atoms.
There are three factors which affect the growth of the magnetic field evoked by a
magnet. These factors include (a) being proportional to the number of turns in a coil, (b) the
diameter of the wire, and (c), varying currents. The current or voltage flowing in the wire is
inversely proportional to the strength of an electromagnet and third, the varying current is
directly proportional to the increase in strength of an electromagnet. A good example of
electromagnets in our daily lives is motors and generators this is through the principle of
electromagnetic induction. Electromagnetic induction is the production of electromotive
force. This concept of electromagnetic induction utilizes the fact that an electrical current in
motion accumulates a magnetic field and a moving magnetic field creates an electrical
current. Generators and motors work in this way; the motor is moved with a magnetic field
which is produced by an electric circuit from a socket. (Jessa, par. 2)This experiment focuses
on investigating how voltage supplied to an electromagnet affects how strong the magnetic
field around it is.
B. Research Question
How do the number of paper clips attracted, by an electromagnet’s magnetic field, vary
if increased voltage is supplied, from a power source, to the electromagnetic circuit? This
question aims to investigate how strong an electric field is with the use of quantitative
analysis. In relation to the Background Information we come to know that increased voltage
ensures a stronger magnetic field being produced hence resulting in a stronger
electromagnet. An increased current or voltage results in more electron flow in the wires
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 3
thus the atoms within the ferromagnet core will arrange and create a stronger magnetic
field as a result of electrical current.
C. Hypothesis
If the voltage given to the electromagnetic circuit increases, then the magnetic field
produced by the electromagnet will increase hence attracting a higher number of paper
clips, towards the magnet. According to Jefferson Lab, increased current (in our case
voltage) leads to more electrons flowing within in the circuit, this determines the strength of
an electromagnet further this also regulates the direction of the magnetic field
(http://education.jlab.org/, div. 6). Increased electron flow will stimulate the magnetic field
and make it stronger and stronger.
D. Parts of the Experiment/Variables
1. Independent variable [manipulated]
The manipulated variable in this experiment is the voltage supplied to the
electromagnet. This is for the purpose of investigating how current/voltage really affects
the strength of an electromagnet. We have decided to have 12 replicas of 4 different
voltages (3 for each), the values will be 4, 5, 6 and 7. After every third trial the
voltage will be increased by 1 and thus 12 trials will be conducted back to back.
2. Dependent variable [responding]
The responding variable for this experiment is the number of paper clips which are
attracted to the magnetic field of the ferromagnet core within the electromagnet. The
data will be recorded in tables initially (for raw data) and then later and averaged table
and graph (for processed data). The table for processed data will contain two sections:
voltage and number of paper clips attracted. Likewise, the graphs will be made with the
same information. The graph will encompass of a trendline to display the averages
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 4
according to the progression of how the strength of an electromagnet increases. The
trendline merely represents the increased strength of an electromagnet.
3. Controlled variables [constant]
There are various constant or controlled variables in specifically this experiment. The
apparatus and materials used were always the same in terms of type, length/mass, shape
and size; there were no alterations in the physical appearance of the experiment. The
reason behind why this should be kept constant is due to every experiment only having one
manipulated variable; if anything in the apparatus or material was changed then there
would be more independent variables to test and mention throughout the whole lab report.
Our sole focus is to test the effect of current/voltage on the strength of the magnetic field.
The weight and type of paper clips was also kept constant throughout the experiment as
that is what was the responding variable thus no alterations should be man-made; the
responding variable is a result of the effects of the experiment. We kept the weight of the
paper clips constant by initially measuring 7 paper clips of the same weight which was 0.36
grams. Next the type of paper clips were kept constant as they were all made for steel wire
and were all purchased together, according to the lab assistants. The weight and type of the
wire was also kept constant this is due to the fact that the air space between the coiled wire
on the Ferro magnet being inversely proportional to the strength of the electromagnetic.
The thickness and length of the wire was always the same- same diameter. The weight of
the wire was 7.93 grams whilst the length being 32 cm. Next, the time given for each trial to
occur is also the exact same. The power supply will turn on, for 5 seconds it will be kept at
the same position and then the electromagnet will be brought over to the plastic container
holding the paper clips and 5 seconds will be given for the magnet to attract as many paper
clips as it can. Finally, the Ferro magnet was also kept constant with regards to its weight,
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 5
length and type. It is proved that thicker Ferro magnet cores produce a stronger magnetic
field. In order to always have the same reliable and valid results we used 3 different nails
(for each trial) being 4.88grams in weight, 7.32cm in length and made of iron. These are all
kept constant in order for them not to influence the final results; only the independent
variable should influence results.
II. Materials/Apparatus
Materials/Apparatus Specifications
Crocodile Wires 3x32cm (7.93 g) Should be made of copper wire
Nails 3x7.32cm (4.88 g) Should be made of iron
Paper Clips 10 (0.36 g) Should be made of steel wiring
Power supply 1 (Voltage) Should be able to reach 10V
Weighing Scale 1 (measure in grams) Should be able to measure in grams
Timer 1 (measure in secs.) Should be able to measure in seconds
III. Procedure
Part A: Setting up the electromagnet
In order to first create an electromagnet use one 32 cm crocodile wire and one 7.32 cm iron nail.
The wire was coiled around the nail to make it a solenoid. The solenoid and Ferro magnet made
up the electromganet which appears as Figure 1.0
Figure 1.0 The diagram illustrated what the electromagnet is to look like after attached the
solenoid and Ferro magnet together
After setting up the electromagnet, the next part of the electromagnetic circuit requires a power
supply and two more 32 cm crocodile wires. The power supply was plugged into the socket and
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 6
set for 4 for the first trial. Next, two crocodile wires were attached to the DC current of the
power supply. Both of the crocodiles were hooked to either one of the sides of the
electromagnet. Figure 2.0 illustrated what the circuit should appear to be
Figure 2.0 This image illustrates what the complete set up should appear as
For the actual experiment, a timer was set for 5 seconds. As soon as the timer was started, the
switch for the power supply, at 4, was simultaneously turned on. After 5 seconds of the
electrons flowing to the electromagnet, the timer was stopped and the electromagnet was
taken towards the plastic container containing the paper clips and placed over for another 5
seconds (start timer again). As soon as the 5 seconds were over, results of how many paper clips
were attracted to the magnet were recorded in the raw data table. This experiment was carried
out twice more for 4 and thrice for 5, 6 and 7 seperately.
Safety Measures:
When carrying the electromagnet it is advised to always wear gloves due to the heat
accumulated in the circuit causing wires to heat up. Next, lab coats should be worn at all times
to ensure no accidents. For extra safety, always make sure a lab assistant is present at your
reach at all times in the case of an emergency. Always make sure that the power supply is
switched off when not using in order to save energy yet also the risk of overheating and
damaging lab equipment.
Validity Measures:
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 7
Validity is how relevant the information obtained is to the aim/hypothesis/research question of
the conducted experiment. In order to ensure this, we kept everything except the voltage
constant so that there are no other interferences in our results. This increases the degree of
accuracy and also makes our procedure a lot more relatable to the purpose of our experiment.
Furthermore, between each trial we maintained a one minute gap so that the wire could cool
down, the magnetic field would cancel out in the nail and the electrons would go back to their
scattered arrangement.
IV. Observations and Data
A. Observation
As soon as the experiment started I was exhilarated to know the outcome. As the 5
seconds passed by of creating the magnetic field, we brought the electromagnet over the
plastic container, not too far and not too close, and waited for 5 seconds for any paper clips
to attract and get stuck to the electromagnet. Within the first 2 seconds, 1 paper clip
attracted whilst the others stayed in the container. We believed this was due to the little
strength of the magnetic field. As time passed and the voltage increased to 2 paper clips,
then 3 and lastly 4 paper clips were attracted to the magnet! It was a great success! We saw,
with the help of the number of paper clips, how strong an electromagnet’s magnetic field
can be with the increase in voltage. Our results very much supported what we were looking
for.
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 8
B. Data
Raw Data:
Table 1
The number of paper clips attracted to the electromagnet after 5 seconds of charging the
electrons in the solenoid of the electromagnet with 4
Voltage
(ohm) Number of paper clips
attracted
Set-up 1 4 1
Set-up 2 4 1
Set-up 3 4 2
Table 2
The number of paper clips attracted to the electromagnet after 5 seconds of charging the
electrons in the solenoid of the electromagnet with 5
Voltage
(ohm) Number of paper clips
attracted
Set-up 1 5 2
Set-up 2 5 2
Set-up 3 5 2
Table 3
The number of paper clips attracted to the electromagnet after 5 seconds of charging the
electrons in the solenoid of the electromagnet with 6
Voltage
(ohm) Number of paper clips
attracted
Set-up 1 6 3
Set-up 2 6 4
Set-up 3 6 3
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 9
Table 4
The number of paper clips attracted to the electromagnet after 5 seconds of charging the
electrons in the solenoid of the electromagnet with 7
Voltage
(ohm) Number of paper clips
attracted
Set-up 1 7 4
Set-up 2 7 4
Set-up 3 7 4
Processed Data:
Table 5
The average number of paper clips attracted to the leectromagnet after 5 seconds of charging
electrong in the solenoid of the electromagnet for 4, 5, 6 and 7
Voltage
(ohm) Number of paper clips
attracted
Set-up 1 4 1
Set-up 2 5 2
Set-up 3 6 3
Set-up 4 7 4 Note: The following numbers have been rounded of to the nearest whole number in order
for the results to be applicable to real life (1.3333 paper clips do not exist)
The table above shows to us the relationship between voltage and the number of paper clips
attracted. The higher the voltage, the stronger the magnetic field resulting in the increased number of
paper clips simultaneously increasing. A trend that can be observed solely from Table 5 is the constant
difference of ‘1’ and number of paper clips and the difference between the voltage and its
corresponding number of paper clips always being ‘3’. Although this may not indicate anything major, it
is a trend to be kept in mind in order to analyse the averaged graph. This table also informs us that our
experiment is heading in the right direction and our hypothesis will be successful with the aid from the
evaluation part of the lab report.
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 10
Fig 3. A graph showing the trend/relationship between the voltage given to the electromagnetic circuit
and how many paper clips were attracted to the accumulated magnetic field.
This graph is extremely significant in order to derive concrete results to support the purpose of
this experiment. The simple conclusion that can be drawn from this graph is that increasing voltage
leads to increased electron flow, which then results in a stronger magnetic field, the outcome of this is
an increasing number of paper clips attracted towards the electromagnetic and at the end we are able
to comprehend that the electromagnet’s magnetic field is stronger by each ohm increasing.
V. Calculations and Questions
A. Calculations
The only calculation involved in this experiment was finding the averages to produce a
processed data table and graph. The average of anything is found by adding all outcomes
divided by the number of outcomes and then rounding it off to the nearest whole number.
It was rounded off to the nearest whole number as the results was the number of paper
0
1
2
3
4
5
1 2 3 4 5 6 7
Nu
mb
er
of
Pap
er
Clip
s
Voltage (ohms)
Strength of an electromagnet's magnetic field
Number of Paperclips
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 11
clips and .33 paper slips do not exist thus this was rounded of to the number whole number
by subtracting the .33.
B. Questions
1. What is the relationship between voltage and current? Current is what changes the
strength of an electromagnet hence why vary the voltage?
The relationship between voltage and current has been outlined and/or highlighted in
Ohm’s Law. Ohm’s Law explains that potential difference, or voltage, across and idea
conductor, is directly proportional to the current through it. When resistance is constant,
but values increase together and depreciate together. The formula voltage is equal to
current divided by resistance is derived from the laws that voltage and current and
proportional to each other while voltage and resistance are inversely proprtional to each
other.
2. How reliable are my results?
Reliability is the degree to which how consistent and stable your results are. In this
process, as seen in Table 1.0 to 4.0 in the raw data section, we always obtained results
for each trial which were very close to each other or the same. My results are reliable as
consistent and stable results are either repeated figures or the same figures and I have
attained these. If you take a look at Table 5.0 in the processed Data section we see that
the averages also are reliable since they all have an equal differencce of ‘1’. This, to me,
indicates that my outcomes are reliable. Furthermore, there are no major changes within
every trial. For instance, one trial for 4 got 1 paper clip and the second trial got 5 and
the third got 7. These results are not reliable as there is some experimental or procedure-
based errors in this. I believe that our results are reliable.
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 12
3. How valid are my results?
Validity is the degree to how relevant our data is to the purpose of our experiment. The
purpose of this experiment was to investigate one factor which affects the strength of an
electromagnet and we chose the amount of current/voltage supplied to the electromagnet
circuit. Our procedure tested how strong the magnetic field was which means how strong the
electromagnet was. The results we found related to how many paper clips were attracted to
the ferror magnet and solenoid whilst increasing the amount of voltage each time. The
degree of validity is high throughout this experiment as my protocol targeted exactly what
we needed to test and from this we have obtained thedesired results.
VI. Analysis/Evaluation
When looking solely at the Raw Data, which is from Table 1.0 to Table 4.0, we see that
all the even numbered voltages (4 and 6 ) had, under the number of paper clips attracted, 2
of the same number of paper clips and 1 different number which was usually more than the two
numbers. For example in Table 3.0 we observe that in two trials 3 paper clips were attracted and
in one trial 4. Next, in Table 1.0 we notice a similarity; in two trials 1 paper clip was attracted
and in one trial 2 were attracted. If this experiment was to be conducted with 8 then there
would be two trials with 5 paper clips and one trial with 6 paper clips. Whereas, in the tables
with the odd numbered voltages (5 and 7), all three trials had the same result. This can be
seen in Table 2.0 and Table 4.0 where either the number of paper clips are all ‘2’ or all ‘4’. As
indicated in all four tables, the number of paper clips attracted have a zig-zag like pattern.
Where every consecutive trial one paper clip increases and then decreases or decreases and
then increases.
Other trends and/or patterns that have been observed in the Processed Data are as
stated here. As indicated in Table 5.0, when looking at the average number of paper clips
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 13
attracted each time, it is always increasing by 1 as the voltage increases. Thus with 4, 1 clip
was attracted, with 5, 2 clips were attracted, with 6, 3 clips were attracted and so on so
forth. Furthermore, the difference between the voltage and number of clips by row is always 3.
For instance, notice Table 5.0 and how 4 subtract 1 paper clip gives us 3, then 5 subtract 2
paper clips results in 3, 6 subtract 3 clips leads to a 3 and 7 subtract 4 clips ends with a 3.
This make the degree of accuracy better due to producing consistent and reliable results.
Through the graph, we are able to visualize how the number of paper clips or the magnetic field,
is directly proportional to voltage. As seen in Graph 1.0, as the voltage inrceases so does the
number of attracted paper clips. The trend line in this graph signifies the strength of an
electromagnet and how it increases.
With regards to our hypothesis ‘If the voltage given to the electromagnetic circuit
increases, then the magnetic field produced by the electromagnet will increase hence attracting
a higher number of paper clips, towards the magnet.’, I believe that this can be accepted, as our
hypothesis has been tested with a reliable and valid procedure which has helped us produce the
desired results and concrete support for our hypothesis whilst also answering our research
question. The strengths of this experiment were that it perfectly tested our hypothesis by using
the manipulated and responding variable mentioned within the hypothesis. Next, the research
question also encompassed of these variables and they were also tested. Further, the variables
which were to be controlled were best tried to keep constant throughout the whole experiment
which they were. In addition to this, we never let the electromagnet touch the steel table in or
labs or the electron flow would also be transferred to the table and this would influence our
results. Thus, we placed in a piece of paper whilst performing the research. However the
limitations were that we only tested our aims and objectives with four modules and 3 replicas.
Next time, if we were to repeat this, I would use 5 modules with 5 replicas each to attain the
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 14
most precise results. I believe that there were no flaws in the method that we chose as it
developed efficient and valid results. Valid in the sense that they were completely relatable to
the purpose of the experiment.
VII. Conclusion
In conclusion our hypothesis ‘If the voltage given to the electromagnetic circuit
increases, then the magnetic field produced by the electromagnet will increase hence attracting
a higher number of paper clips, towards the magnet.’ Can be accepted due to the well-
supporting results produced by the protocol of this investigation. It has come to our knowledge
that the increased flow of electron ensures a faster allignment of electrons with a larger number
of electrons being aliigned. Further, these are some contributing factors to a magnetic field
being produced. As soon as this field is produced, depending on how strong it is, it attracts items
with magnetic properties accordingly. Furthermore, our research question has also been
answered. ‘How do the number of paper clips attracted, by an electromagnet’s magnetic field,
vary if increased voltage is supplied, from a power source, to the electromagnetic circuit?’ After
experimenting, we have figured out that the strength of an electromagnet is thoroughly
affected by the increase in current or voltage supplied. This is due to the increased eletron flow
and rapid atom allignment.
VIII. Sources of Error
The first source of error seen in this lab experiment was a human error which is usually
present in all experiments (classroom level). We were to start our power supply and timer
simultaneously. It is how fast human reflexes work which determine how accurate our timing is.
If we use phrases such as ‘1…2…3…START!’ it still would not be affective as everyone reacts to
situations in different ways; although I may be prepared I would start exactly when I pronounce
the letter ‘t’ while my partner would start the power supply after finishing the pronounciation of
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 15
the word. One way to improve this would be for me and my partner to say the phrase together
and also decide as to when we will start the power supply or timer. Additionally, one partner
can say the phrase while the other can both start the timer and power supply together so that
the difference between timing would be less. This is effective as if the same person does he or
she is able to control their own timing and how to perform two activities at the same time.
Another source of error which may have altered the results was the height between the
electromagnet and plastic container filled with 10 paper clips was not determined. We simply
charged the electromagnet for 5 seconds and then placed it over the contained to obtain
results; we did not have a fixed height to keep it away from. We tried to keep it not too far and
too close however this makes our results qualitative and not quantitative. For improvement in
the future, a small book can be made to stand of a certain height, and we can hold the
electromagnet from that height to esnure accuracy and reliability. Thirdly, an error when
processing the data for this report was the averages found of Table 1.0 and Table 3.0. When
adding the three figures (for instance 1, 1 and 2) we get 1.33 yet this was rounded off to 1 paper
clip as 0.33 paper clip is not possible. Rounding off a number makes it an assumption and again
makes our results more quantitative than qualitative. The last, not necessarily error rather a
mistake was that we only had 4 modules and 3 replicas of each. In order to attain more reliable
and concise results we could have had 5 modules with 5 replicas each. To improve the way we
collect data, if we had more replicas, the decimal places would have a lesser chance to exist thus
we could improve this and have 2 effects of it. Overall, our procedure went well and we
acquired the answer to our research question and our hypothesis.
Type-In Your Hypothesis Here. Use The IF-THEN-BECAUSE Format Discuss In Class.Dhanani 16
References:
Gagnon, Steve. "Questions and Answers - How Do I Make an Electromagnet?" Jefferson Lab. Jefferson Science Associates, LLC, n.d. Web. 23 Nov. 2014. Jessa, Tega. "Uses of Electromagnets." Universe Today. Universetoday, 8 Sept. 2009. Web. 23 Nov. 2014. "Magnets and Electric Current." BBC. BBC News, n.d. Web. 23 Nov. 2014.