In my experiment my variables will be the amount of coils as it will be coiled around the nail and this number of coils will be varied at 10 coils then 20 coils then 30 coils then 40 coils then 50 coils then 60 then 70 and finally 80 coils. The current will be a constant so it will be the same all the way for a fair test it will be measured in amps. The size of the coil will always stay the same throughout the experiment, as we do not have extra facilities. The amount and size of the iron will star the same, as another constant-it will be a large nail, as we don’t have larger pieces of iron. I will use paperclips as the metal that the nail will pick up.
In our preliminary experiment we connected up the apparatus, roughly, like in the diagram below.
Our circuit looked roughly like this in our preliminary except we had connected an ammeter as well, in series with the power source.
To make my test fair and safe I will always use the same nail because some nails are bigger or smaller than others so some will pick up more paperclips than others, I will also use the same piece of wire because some wires can have extra copper wires than others causing more or extra paperclips being picked up. To make it more of a fair test I should keep the current exactly the same because more current can pick up more paperclips and less current will pick up fewer paperclips.
I predict that the more coils we add to the electromagnet, the stronger the magnetism will be and therefore the larger amount of paperclips the magnet will be able to suspend. So if you double the amount of coils, than the magnet will pick up double the amount of paperclips.
I predict that when the more coils are added to the iron nail then the more paper clips that the nail will attract as each turn will produce a certain strength or a magnetic field. As the more the turns the stronger the magnetic field would be. Will show my prediction in a graph.
Here the y-axis represents the amount of paperclips that are attracted, and the x-axis is the amount of coils around the iron nail and it shows a steady increase in the attraction of the paperclips. I.e. number of paper clips is directionally proportional to the number of turns.
The reason for the sudden vertical direction of the line is because at an extent the magnetism will stop increasing. Although I do not think that my final graph will look like my prediction graph because I don’t think I would have magnetised it to that extent. To fully magnetise the magnet you would have had to put a few hundred coils around the core, where as I am only going up to eighty. So my graph would look more or less like this.
Obtaining My Evidence
In our preliminary experiment I connected up the apparatus, after gathering them together, as shown in the diagram below.
Whilst we were doing the preliminary I noticed that the power pack kept on blowing and so I decided to fix this by using a variable resistor in the secondary experiment, so that we could control the current.
The reason why the power pack kept on blowing was because the power pack, for safety reasons could only hold four amps, so if there was more then four amps then it would cut the supply to the circuit. Therefore we need a variable resistor to make the current flow.
These are the results that I collected from the preliminary experiment.
The results look inaccurate just by looking at them. You can straight away see the anomalous result in the first couple of results. You can see that they are not very precise as it is clearly shows no pattern between the increase of coils and the increase of the number of paperclips it is able to pick up.
We corrected the faults. We connected a variable resistor into the circuit, so that the current was variable. We made sure that we did everything accurately and did the experiment three more times; these were the results we got.
You can see that there is one inaccuracy in the first couple of results. Apart from that the rest looks precise and you can see a clear pattern in the results. You can see that the result increase by an average of about 10 paperclips, every time you add 10 coils to the core.
These results also look quite accurate. They are very similar to the first set of results I had gathered, although you can see another anomalous result at the fifty coils mark. It had picked up more paperclips than it should have. There is also not such a very clear pattern to these sets of results. But they are more accurate then the results we collected from the preliminary work.
These last sets of results are definitely my most accurate and precise, you do not see any anomalous result and u can see a clearer pattern.
These last set of results show the average out of the three. They are very much similar to the results that I had gathered from the previous test.
Analysing My Evidence
The more you increase the amount of coils, the stronger and larger the magnetic field becomes. The graphs below show that when you add ten more coils to the iron nail, about five-fifteen paperclips are attracted. So my prediction was right, when you increase the amount of coils, than the magnets magnetism also increases in proportion.
you can see that these graphs all resemble my predicted graph, they have a straight, diagonal line running from the bottom left of the graph to the top right.
This graph has a few more anomalous results but you can still see that it has the same pattern. When you increase coils, you increase the magnetism, and so the number of paperclips picked up will also increase.
These are my most accurate results, collected. The final set of results.
This is the average results graph and so it will be the most accurate data I have. You can see it has the best line.
Evaluating My Evidence
