Diagram:
Plan:
Step1: Set up equipment as shown on diagram
Step2: Draw a table to keep results as shown below
Step3: Start experiment
Step4: Work out the resistance using R=V/I
Step5: Get first set of results then repeat the experiment a second time
Step6: Once you’ve got both set of results get an average. To get an average, add the two results together then divide by two.
Fair Test
We made sure that the experiment was done fairly by using the same type of wire and only changing the length of the wire for each experiment.
Safety
For the safety of others and us we will be using a smaller power pack to avoid excessive of voltage.
Accuracy
I will do my best to read the ammeter and voltmeter accurately as possible trying not to make a mistake. I will make sure that the crocodile clips are placed properly at the right length.
I will allow a few seconds for the ammeter and voltmeter to settle before writing the results down.
Prediction and Hypothesis:
I predict that if the length of the wire increases then the resistance will also increase in proportion to the length. I think this because the longer the wire the more atoms and so the more likely the electrons are going to collide with the atoms. So if the length is doubled the resistance should also double. This is because if the length is doubled the number of atoms will also double resulting in twice the number of
collisions slowing the electrons down and increasing the resistance. My graph should show that the length is proportional to the resistance.
First Results
Second Results
I will now work out the average.
Average Results
I will now plot a line graph of the average results.
Results and Evaluation
The experiment proved to be a success and it went very well although it could be improved by trying other lengths, different voltages but also a different type of wire to be able to compare the resistance difference this would make a more interesting experiment.
My results are presented in a table to show the resistance through a wire.
In my prediction I said that as you increase the length of the wire you also increase the resistance and from the results table you can see that the prediction I made was absolutely correct. My results don’t show anomalous results, which prove that the experiment went well.
I think that I did everything I could to keep this experiment fair as possible.
The problems that I had was to set up the equipment but I soon figured it out.
The resistance of a wire depends on the number of collisions the electrons have with the atoms of the material, so if there is a larger number of atoms there will be a larger number of collisions, which will increase the resistance of the wire. If a length of a wire contains a certain number of atoms when that length is increased the number of atoms will also increase.
Bibliography
-Physics for you
-Teachers notes
-Class notes
