Investigation into wires and resistance Essay

The countenance 2 were done using two digital Multimeters so presumably the results on the second two planks atomic number 18 more accurate. psychometric test 1 ammeter/voltmeter aloofness of constantan (cm) capability remnant (volts) Current (amps) confrontation (ohms) Ammeter/voltmeter twin Length of constantan (cm) authority leaving (volts) Current (amps) rampart (ohms) Multimeter Test1 Length of constantan (cm) potential drop difference (volts) Current (amps) Resistance (ohms)  Multimeter double up Length of constantan (cm) Potential difference (volts) Current (amps).Resistance (ohms) 1Average bulwark over all four tests Length (cm) Potential Difference (volts) Current (amps) Resistance (ohms).Constantan theory undergrounds Using the chemical formula R=E(L/A) I down pull together the exact resistance of a aloofness of SWG24 constantan regardless of any associations or battery faults Length (m) Resistance (ohms) And this table orders the results of the c omputer guise (the computer simulation incorporates the resistance of the connecting cables into the resistance) Length of constantan (cm) Potential difference (volts) Current (amps) Resistance (ohms).We measured the resistance at 0 cm to be 0. 35 ohms. However this stoolnot mayhap be true beca persona the average at 10cm was 0. 2015 and the resistance Analysis This is the average index (IV) plotted against the average resistance This shows that as the aloofness of the constantan increases more advocate is required to drive the electricity by dint of the fits and at the same time in that respect is in like manner more opportunity for the actor to dissipate as heat and light.This make is use to swell effect in electric fire elements where the wire is spiral to add greater length. My average results of our tests The results from the former computer tests Conclusion From my results and the computer interprets, I can see that the ratio amid the length of the wire and i ts resistance is some one-dimensional and the theoretical resistance is merely linier. This makes sense because the constantan wire is of homogeneous thickness. The resistance on my tests isnt perfective aspect and this is probably because of the hotness effect as informed earlier.Two things that we can see from this chart atomic number 18 that neither the electromotive force nor the on-going are grapevinear. This is because the enteriness of the batteries are delimited and therefore, as the resistance increases to infinity the sure and voltage will level to the capacity of the battery, curving the graph. Still, you wouldnt expect the voltage or to be linier in a lap covering like this because of the ingrained properties of the batteries and the heating effect of the dress circle. Another thing we can see is that as the resistance lessenings to null the current and voltage will decrease to zero.However because the circuit will have its own fixed intimate resist ance including The battery, the meters, the circuit wires, the contacts etc a theoretical zero resistance is not practicable in this circuit. in addition as the length of wire decreases to zero the results will befit less accurate as the extraneous resistances (mentioned in a higher place) become more significant and the temperature rises in the wire are more significant. For exercising if the intimate resistance of the circuit we used totaled 3 ohms and we were testing 0. 001 cm of constantan equaling 0.001958 (if R=E*(L/A) is true) indeed(prenominal) the total resistance is 3. 001958 ohms, which is expressive style transfer the actual total.And as you make the circuit smaller there is less resistance so the current is higher consequence that more heat is generated. My resistance results on my hand drawn graph are very nearly linear and that supports my prognostication that if you increase the length of wire then the resistance increases. As shown, the line of R=E*(L/A) is linear and if you add the internal resistance of the assuagement of the circuit to that, it is compose linear, but appears level on the graph.If you borrow a point on the linear theory line and double its determine then those values are true, kernel that in the lines formula X is instanter proportionate to Y (this is safe to ask as there are no outside interferences i. e. battery, wires etc only the length and diameter of the constantan). The same is almost true (although shouldnt be) for my total resistance average line. However, you cannot push back the values of a point on the computer line, double them and expect them to be true.This shows that for this line X isnt directly proportionate to Y but is R=E*(L/A)+the internal resistance of the rest of the circuit. Evaluation Comparing my results to the computer generated ones Id say that the experiment went sort of well. Although some off connections in our circuit were slightly rusty and damaged the results show that it wasnt too a good deal of a problem. The range of results obtained was sufficient to form good averages which were comparable to the results obtained from the computer and the results generated by R=E*(L/A), and the results supported my prediction.I believe the results to be accurate because they are passably consistent with each other. For example on the multimeter test at 50cm the resistance was 0. 9375 ohms and on the repeat I got 0. 88 ohms. This substance that there was only a 0. 0575 ohm difference between them. However the results obtained from the voltmeter/ammeter tests were less accurate as it is very hard to read off them to more that 2dp. One unconnected thing with the results I obtained was that the resistance was much mooer than I expected. This is shown by the graph.I would have expected the line to be closer to the computer simulation than the R=E*L/A line because R=E*L/A doesnt account for resistance where as the computer simulation does. My experiment sure enough had resistance in the circuit and stock-still my experiments line falls almost on top of the one that doesnt. There are a few routes to explain this. The current in the simulation was lower than the current in real life, the internal resistance of the circuit was very low (which I find hard to believe) or the measurements werent accurate enough, either way there is no definite answer.Also on my hand drawn graph there are 3 unmistakable anomalous results, which didnt fall on the line of best fit. They are credibly to have been caused by poorer measurement, kinks in the wire or a bad connection (more sources of error have already been state in the plan). However, I think that the tell is still sufficient to support the conclusion. The way we set up and conducted the experiment was the bill however if I was to do repeat he investigation I would use much shorter circuit wires and use split up connections to minimise circuit resistance.It might as well be a good humor t o use a rectifier instead of batteries so that draining power isnt an issue. You could also extend the investigation by standard other variables such as temperature and wire diameter. Show preview only The above preview is unformatted text This student written piece of work is one of umteen that can be found in our GCSE Electricity and Magnetism section.