I have used Ohms law to explain how and why my choice of method will produce precise and reliable results. Ohms law states: “that the current through a metallic inductor is directly proportional to the voltage across it, provided the temperature was kept the same. As I have stated in my variables, I must keep temperature constant therefore I will get the most accurate results to show in my investigation. However if the temperature was to increase, the heat will cause the speed of electrons to increase as the current increases causing more friction and the whole experiment to heat up. This will cause the nuclei to gain kinetic energy and vibrate more vigorously therefore taking up more room and making it even more difficult for he electrons to get past. This means the resistance has increased.
To prevent this from happening, I will aim to keep a constant temperature throughout the experiment; I will try to keep the current low by switching off the current between readings so the wire will not heat up. GRAPH DESCRIPTION: In the graph, I have drawn out you case see the shape consists of a straight line that passes through the origin with a positive correlation. It is clear that as the length increases, so does the average resistance of the wire. After studying Ohms Law, I now now that the length and resistance are directly proportional to one another meaning the length and resistance have increased at the same rate.
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This theory is further backed up by my graph as it is a straight line the whole way through and passes into the origin. The shape of my graph shows there were no anomalies so therefore my results are very reliable, as the line of best fit ran very close beside and through most of my results plotted on it. Overall the shape of my graph backs up the prediction I made earlier that “as the length increases the average resistance will also increase. This shows the experiment I carried out and the prediction I had made were very reliable.
Using my table of results, It is clear that the results I had achieved were very similar the whole way through and carried out the same pattern showing that my results were very reliable and carried out effectively. IMPROVEMENTS: Heat- To make sure I carried out a fair test, I tried to prevent till much heat affecting my results by turning off the power supply between each test however it is hard to judge whether it was turned off long enough and equally between each time to make ad it turned off for each time and waited until it was as cool are possible before repeating the experiment.
Wire- The wire was rather bendy and kinky, is it was difficult to Judge the exact length of wire. To improve this, I could have straightened it out until there was no kinks that could have affected my results. Reliability- To produce the most reliable results, I repeated the experiment for each length 3 times so if there was any unusual results compared to the rest, I could easily point it out and know to do it again.
Furthermore, to obtain the best results, I also took an average of all the results I had achieved for that length so my overall results would be little affected if one recording turned out to be odd. To back up my results that as the length increases, as does the average resistance of I wire, I have based my findings using the Ohms laws theory that the results I have achieved are due to the more fixed ions in the longer wire that make it more difficult for the current to travel through quickly this increasing the resistance. This is clearly evident in my results and portrayed in my graph.