I carried out an experiment to find out whether the length of a wire affects the resistance. After analysing experiment and repeating three times, I have come to the conclusion that the length does affect the resistance as the resistance was less when the length of the wire was long. And when the wire is short the resistant is less. This shows there is a positive correlation between the two factors. While doing my experiment I noticed that the amperes are always higher than the voltage.
I used a 100cm ruler which had conductor at each end. I took a wire and wrapped the ends of the wire round nails on the ruler. Furthermore, I used crocodile clips to connect the power box, wire and voltmeter together. I used the same wire through all the experiments; this caused me to get wrong data because the wire got burned and caused more resistance. Therefore to improve my experiment, next time I could use a new wire each time I repeat the test. So once I do 3v 1st experiment, I change the wire for 3v 2nd experiment. This will improve my experiment as it would be fresh data and the wire wouldn’t cause more resistance.
I did my experiment on Constantine and wrote down the measurements every 10 centimetres. First I did my experiment on volt 3 and then tested it on volt 4 and 6. I didn’t experiment on volt 5 because I wanted to see if the results made a huge difference. I repeated my experiment at one voltage 3 times to have a reliable result. Apart from the voltage, I did everything the same for all the experiment to get an accurate result. After, I worked out the average by adding the three results of one voltage and dividing it by 3.
Average = 1st result + 2nd result + 3rd result ÷ 3
I used a scatter graph to display my results because I wanted to draw a line of best fit so I can see if there are any outliners. Using a scatter graph helped me see if there was any correlation in my data. There were a few outliners which caused a little problem for me to draw my conclusion. But after repeated the experiment on two other volts, it solved the problem.
1st result – 1.37amps 1st – 3.78v
2nd result – 1.35amps 2nd – 3.79v
3rd result – 1.36amps 3rd – 3.80v
Average - 1.32amps + Average - 3.79v = Resistance – 2.87
After finding the average of amperes and voltage, I used this to work out the resistance. Resistance is:
Voltage ÷ Amperes
While the voltage pushes the current around the circuit. There are some stationary atoms which get in the way of the current, causing a collision. During this collision, some of the electrons in the current rub off into the stationary atoms. This causes the current to lose some energy and turn to heat.
By looking at my scatter, I know my experiment is accurate as most of the data