Investigation of electromagnetism

Investigating the number of turns on the strength of the electromagnet, this experiment is to find out more about the effect of number of turns on electromagnetism. This is why the number of turns can be altered and has to be altered as this is our variable. We will be using a large battery for providing the current. Then the above counts for the continuation of the experiment. The controlled variables are the voltage on the battery, the same soft iron core and the same wire. I kept all these variables constant so the investigating of the turns would not be influenced by other factors; I only altered the testing variable. The responding variable will be the amount of filings picked up.

Investigating the effect of current on electromagnetic strength, this experiment is to analyse how the current flowing in the wire affects electromagnetic strength. This time through the set up will include a resistor to control the current flowing to the electromagnet. Instead of using the large battery we will use the power packs to provide power and connect the resistor. It will also include an ammeter as this is our variable, which we are testing for. The number of turns will be the maximum possible. Now the above also applies through the continuation of this experiment. Here the controlled variables are going to be the ohms on the resistor, the wire, the soft iron core, the same ammeter and the amount of turns of wire around the magnet. I want to keep these the same because they are not my testing variables. The altering variables are going to be the voltage on the power pack and so obviously the ammeter reading on the ammeter. The responding variable is the amount of filings picked up in grams.

The type of core material that makes the best electromagnet, this experiment is to analyse the effect of material on electromagnetism. The number of turns will be 25* It will include a one cell power battery. The cores will be altered. Again the above applies for the continuation of the experiment. The cores include: iron, no core, steel, copper, brass and wood. The constant variables will be the wire and the turns of wire around the magnet as well as the voltage supplied by the battery. These are kept the same as to not influence the testing variable, which is to analyse how the core material affects electromagnetism. The responding variable will be the amount of filings picked up. This will all be recorded in a table as shown below.

RESULTS

Investigating the number of turns on the strength of the electromagnet

Number of turns

Mass of filings (g)

0.1

2

0.4

5

.56

0

7.47

5

24.4

20

28.8

Investigating the effect of current on electromagnetic strength

Current (amps)

Mass of filings (g)

0.15

0.02

0.35

0.04

0.55

0.02

0.75

0.05

.15

0.10

The type of core material that makes the best electromagnet

Core (each 25 turns)

Iron filings picked up (g)

Iron

3.65

No

0.20

Steel

3.59

Copper

0.05

Brass

0.15

Wood

0.15

CONCLUSION

The factors which effect electromagnetism are: the number of turns of wire around the magnet, the current flowing through the wire and the core material which is used.

Number of turns of wire, the more turns you have the better. Because then the amount of electrons present is greater. There for they create a larger magnetic field and produce a stronger electromagnet.

Current flowing in the wire: again looking at the results I can see a proportional line indicating that the higher the current flowing through the wire the better the electromagnet is. This is because the force and strength of the electromagnet increases as the current increases. It produces a greater attraction.

Core material used: as I expected the best core material was a metal. Both steel and iron were very close although steel was the more dominant one, according to my results. I think it should have been iron as it has the best shape for inducing the flow of the electrons. But I was not wrong in saying that it would certainly be a metal. As wood is made up of many different layers and so can not be induced. Also no core material would just include the wire and nothing else, which does not maintain a strong magnetic field.

EVALUATION

To improve the accuracy of this experiment you could repeat it more often and then calculate the average. You could also put more effort in transporting the iron filings across from one paper to another, to not affect any of your results. I think there must be another way of attracting the filings, because sometimes we might have held the electromagnet there for longer or sometimes we might have taken more iron filings then it could actually carry. I think this aspect is the hardest to handle equally. It also interferes most with the results if something goes wrong.

Looking at the results it is very clear what they show. By this I mean that the line of best fit shows a very strong correlation between the densities of the points. This indicates that the results were rather accurate. I was not very happy with the result of the core material. I was expecting iron and not steel to be the best core material. This is because from all materials iron has the best shape for inducing electrons and persuading them to flow in a direction. This was probably due to experimental failures.

Other aspects I could investigate are temperature and how it influences magnetism. You could also look into the shapes of the materials. I think this aspect also affected our experiment. Because we had used different shapes for different materials, for each experiment. A larger area of material would have a stronger magnetic field, as it has a bigger surface area and so would have a stronger magnetic field.

Generally I think it was an interesting experiment to do, and I also had enjoyed analysing the aspects of electromagnetism.

E.g. If the iron filings still fall off, after the circuit has been switched off.

(footnote continued)

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