Factors affecting the Strength of an Electromagnet · PDF fileFactors affecting the Strength of an Electromagnet Grade 11 Physics 11/25/2014 Fairview International School Qanita Dhanani

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


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


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

http://education.jlab.org/


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,


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


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:


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.


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



Voltage


attracted

Set-up 1 5 2

Set-up 2 5 2

Set-up 3 5 2

Table 3



Voltage


attracted

Set-up 1 6 3

Set-up 2 6 4

Set-up 3 6 3


Table 4



Voltage


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


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.


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


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.


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


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


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


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.


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.

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Factors affecting the Strength of an Electromagnet · PDF fileFactors affecting the Strength of an Electromagnet Grade 11 Physics 11/25/2014 Fairview International School Qanita Dhanani