From my group’s graph I can see that as the length of wire increases so does the resistance, but at 60cm there is a steep fall in resistance. This could be down to a few factors but it is probably temperature, which I’ll discuss at a later point. It is a positive correlation if we ignore the plot at 60cm as it is an anomalous result.
In the other graph which I obtained from another group you can see that there is a roughly equal amount of increase between each length, until 100cm where it is the same as the resistance at 90cm. The length of wire and resistance are directly proportional to one another meaning that this graph has a positive correlation.
The results have proved that the length of wire does affect the resistance of the wire and my prediction has been proved correct. A longer wire has more resistance because there are more atoms in the way of electric flow, and a shorter wire would have fewer atoms in its pathway.
Like in the real experiment the resistance increases with the length. The volts go up and the amps go down. These tests were carried out in the same way and in the same conditions as the others – room temperature. I stuck with these lengths as they were not hard to figure out, which is why I added a further 5 more. By doing as many as possible will give you better results and will make your results more reliable.
I think my results were quite dodgy, and didn’t give an accurate account of this experiment. I got strange readings on my first test as they were different to my second and third tests. My second and third tests were very close to each other and didn’t show any results like the first test did. The reason for this could be because they were carried out on different days so the room temperature could be affecting it, or maybe there was something faulty with some of our equipment. This is why I took my average from tests 2 and 3, with which I then used to find the resistance. But even by taking only tests 2 and 3 it still gave me an odd resistance for the test at 60cm. I think this had something to do with the temperature as it couldn’t twice have just been a co-incidence. The ammeter reading was way off the pattern of the amps decreasing as the length increased. You can see that the two results above and below it are similar so something has happened at this point. The temperature seems to have decreased as the resistance has gone down. The room temperature didn’t differ as the other experiments were done at the same time of day.