Hypothesis
I think that the amount of current flowing through the wire will be directly proportional to the length of the wire. As the length increases so will the resistance proportionally.
Apparatus
I will need the following things for this experiment:
A voltmeter, ammeter, battery power supply, key, stick with nichrone wire, metre stick and leads.
Method
- Set up your apparatus according to diagram one after following the safety precautions.
- Place the key 10cm up the wire.
- Record readings onto table from ammeter and voltmeter. Resistance = V/I
- Do this 3 times, each with a different voltage – 1.5, 3 and 4.5volts.
- Repeat at 20, 30, 40, 50, 60, 70 and 80cm.
- Find the resistances and average resistance and record these in a table.
R1+R2+R3/3 = Average Resistance.
Scientific Background
Here I have a 5cm wire and a 10cm wire. Because there are double the amount of electrons in the 10cm wire than the 5cm wire there will be more collisions and therefore double the resistance.
Interpreting and evaluating
Upon reading my results I found out that my hypothesis was correct. This was that the current flowing through the wire was directly proportional to the length of the wire. I know this because in the graph, the longer the wire, the higher the resistance.
Fair Test
In order to make this a fair test there are a number of factors that I must
take the following factors into consideration:
- Make sure that the test is repeated the same amount of time for all lengths.
- Make sure that all of the voltages are the same for each length.
- Make sure that the key is held on the wire for the same length of time on all of the lengths.
Results
Here is a table of my results.
Here is a graph of my results.
This graph shows a positive correlation between the two axis.
Conclusion
My conclusion is that the longer the wire is, then the higher the average resistance will be and we can see this in both the table and graph.
Conclusion
