In order to investigate how the resistance of nichrome wire depends on its length I will firstly have to know the formula for resistance (resistance = voltage ï¿½ current). So, in order to find the resistance of a length of nichrome wire, I need to put the wire in a circuit, and then measure the voltage across it and the current through it. I will do this for different lengths of nichrome, simultaneously recording my results.
List of materials used:
1. Wire cutters
2. Copper Wires
3. Crocodile clips
4. Single Beaker (containing water)
5. Single Ammeter
6. Single Voltmeter
8. Two Pencils
In my experiment they key variables are: Length (measured in mm), Voltage (measured in V) and Current (measured in ohms ?)
When I conducted the experiment very few unexpected results occurred, however I did notice that on the 35cm length of nichrome wire, the current somehow decreased, when naturally (as both the sequences before and afterwards suggest) it was supposed to increase.
I firstly considered these results as an error however after a second (and later third) try I concluded that the results that I attained in the first place were correct, and I wrote them down in the graph.
For the conclusion I would like to state that for every 5cm decrease in the length of nichrome wire, the voltage decreases by approximately 0.1 V, whilst the resistance decreases by approximately 0.7 (from 45-40cm), followed by 0.
6 (from 40-35cm), followed by 0.5 (from 35-30cm).