The crocodile clips on the wire and the position on the variable resistor were changed.
1- The apparatus was set up.
2- Two crocodile clips were put on the wire, one at 1cm and the other at 100cm.
3- Changed the position on the variable resistor three times.
4- Recorded figures on amp meter and voltmeter each of the three times.
5- Calculated the average of the three.
6- Using the averages (and R=V/I), calculated the resistance.
7- Repeated steps 1-6, reducing the length of the wire by 10cm each time, i.e., 100, 90, 80….until 10cm.
The things observed were the readings on the amp meter and voltmeter and recorded them.
It was kept a fair test by keeping the wire still and changing the position of the variable resistor 3 times by quite a long distance– beginning, middle and end of it.
The test was not repeated but to make it more accurate the position on the variable resistor was changed three times.
Sources of information used to help were the internet, a dictionary, the internet and some books.
CONCLUSION:
The results show that as the length of the wire decreases with it:
100 resistance is 18.5
90 resistance is 17.5 and so on…
In my prediction I said that if the length increases than the resistance will also increase in proportion to the length. From my graph I have shown that my prediction was correct, as the Line of Best Fit is a straight line proving that the resistance of the wire is proportional to the length of the wire. The length of the wire affects the resistance of the wire because the number of atoms in the wire increases or decreases as the length of the wire increases or decreases in proportion.
EVALUATION:
The method could’ve been wrong because if the wire moves the reading changes. Also the crocodile clips might not have been in the exact places.
The observations and recorded results at some points weren’t accurate, the reading on amp/voltmeter kept flashing to two numbers with a 0.01 difference, so we had to round it up.
The averages would have been a bit more accurate if the position on the variable resistor had been changed a few more times.
There was one anomalous result. This result should not count as one to help the experiment along. This could’ve appeared because the wire moved or the average is inaccurate.
The method could be improved by using different types of wire as well, e.g., copper.
The method could be extended by changing the variable resistors position five times rather then three.