Results: I have calculated the resistance using the formula: R=V/I. Resistance is measured in ohms and the unit uses the symbol ?. Experiment 1 – battery voltage = 6. 12V: Length of putty in cm Amps in A Resistance in 3 Experiment 3 – battery voltage = 6. 00 Length of putty in cm Amps in A Resistance in ?Analysis of Results: This graph shows me the results for all three of my experiments, and there is a line of best fit for each experiment. There are some inaccuracies as the voltage was slightly different for each experiment, and I feel that points for the later experiments are also out. This is visible in my results and is maybe due to the fact that the same piece of putty was used for all three experiments, and so heat from my hands must have affected results. I have taken the averages of my results.
Length of putty in cm Resistance in ? hese are my average results. These results were plotted on a graph (see graph) and they show a visible decrease in resistance as the length of putty decreases. This would prove my prediction and hypothesis to be correct, as it states that the putty will have lower resistance when the length is shorter rather than longer or the resistance of a conductor is directly proportional to its length; due to factors such as loss of energy to heat, higher rate of collisions etc.
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(see prediction and hypothesis) However, when looking at my graph I noticed that the two points representing the shortest lengths of putty were out. This could be because as the putty was being worked, rolled and cut throughout the experiment it had become warmer and softer due to the heat from our hands; this could have affected the resistance. Evaluation: My results have proven my prediction and hypothesis to be correct, in that resistance is directly proportional to the length of the conductor, in this case the conductive putty.
I think my results were quite accurate, but what may have let them down was the fact that the battery’s voltage was slightly different for each experiment and the coins used to connect the wire to the putty, did not stay in place very well. I also noticed there was often a big jump in amps and resistance between 10cm and 5cm of putty. This can be seen by looking at my results and the graph, and I have concluded that this is probably caused by my hands transferring heat to the putty by means of conduction, as the putty is regularly in contact with my hands during the experiments.
I expect this could be separate experiment, in which we could investigate how temperature affects resistance. If this experiment was going to be redone, then I think I might use a new battery for each experiment, and record the voltage as constant for all experiments. Also I would maybe use a different method to connect the wires to the putty, like maybe sticking the wires directly and vertically into the ends of the putty.
Another thing to do would be to use temperature or even cross-sectional area as a variable alongside length, and to do a series of experiments involving increasing the length while decreasing the cross-sectional area, and vice versa. Conclusion: I think this experiment was a success in that it proved the theory that resistance is lower with shorter lengths of conductor and my hypothesis declares that as the electrons have a shorter distance to travel if the length is shorter, there are fewer collisions and less energy is lost to heat unlike in a longer length of conductor, so the putty will have lower resistance.
Therefore my hypothesis was correct and I have successfully concluded my experiment proving that resistance is directly proportional to the length of conductor. Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.