By the research and predictions I have done I have decided to test the resistance in different length of wire because the class is resourceful as it has enough wire for everyone, it has all the apparatus needed, all the equipment and materials are readily available and we have enough space in class to do the practical experiment. My prediction is “the longer the length, the higher the resistance would be”. I would be sure the results would be the same because I have been researching on the length on some books and sites. I know that I will get a graph showing the resistance going diagonally showing the wire length on the x-axis and average resistance on the y-axis. I have repeated my results to get a fair average test on my graph. To make my experiment fair I am going to vary the length of the wire to get a different answer for each of them so that I could prove my prediction. I will keep the entire appliance the same with the same voltage so that the results acquired won’t be real and that’s why I put the voltage for the test the same. I have planned my results so that it will be fair as I dam going to do one preliminary to check if it was going as I expected ( the longer the wire, the higher the resistance) and a triplicate test so that I get an average between the three results so the results I will get will be fair. And the range would be 100cm, 80cm, 60cm, 40cm and 20cm as if I tested a range with a difference of 20cm it will be hard to get an accurate graph and to get it more accurate I tripled the test. To ensure my results are accurate I will take my time to get the results and check all connection so that all the appliances don’t have any default.
I will acquire the results by getting the voltage and amperes in a circuit by the help of an ammeter in series and a voltmeter in parallel with the piece of wire. Like this:
With the results I will find the wire resistance with the formula V=RxI. I will do three tests with each of the wire I am using then I get the average of the three results so that the test would be fair. I will use 100cm, 80cm, 60cm, 40cm and 20cm wire. From my factors I will predict that the longer the length the higher the resistance would be. I would be sure the results would be the same
This graph and chart results shows you the average results I got for my test. The graph shows the wire length to the resistance. It shows that the longer the wire, the higher the resistance. That means my prediction was right because it clearly shows the lower resistance means smaller wire length. As the wire is short, the electrons move faster through it and there is less to travel. Example: if the distance of the wire is long the electrons will take more time to go through which means it has a high resistance. As I know resistance is meant to retard the electrons
Apparatus:
- ammeter
- voltmeter
- wire
- power
- Croc. Clips
- variable resistor
- connection clips
Method:
- get apparatus
- connect apparatus as shown on diagram on page 3
- measure wire
- 100cm, 80cm, 60cm, 40cm and 20cm
- connect 100 to circuit then look at voltage and current amount
- write results down
- write two more results
- start again from #5 but use 80cm, 60cm, 40cm and 20
- write everything down like the chart that I have done on page 4
Safety:
- resistance wires may get hot enough to burn your skin which may be very dangerous
- large current might burn plastic on wire to give off toxic fumes
Evaluation:
Through all those experiment, chart and graph I have made I have found that my prediction turned up right which is “the longer the wire, the bigger the resistance”. I have fully understood the calculation and the way resistance work in a circuit. The results that I have required gave me proof that the length of the wire affects the resistance
