Resistance of a Wire

Plan
In this investigation I am going to look at how the resistance of a piece of copper wire differs depending on its length. In stages of 10cm. For this I will need:
· Power source: To supply the electricity.
· Variable resistor: To control the voltage flowing across it.
· Voltmeter: used to measure the potential difference between two points.
· Ammeter: used for measuring amount of current in a circuit.
· Crocodile clips: to alter the length of the copper wire without actually cutting it.
And obviously copper wire and leads to connect the instruments together.
There are certain aspects to the investigation that could affect the results, these are known as variables. Some of the variables that are relevant to my investigation are:
· Length
· Thickness
· Temperature of wire
· Material used
· Voltage passing through

To make the data I collect valid I must maintain control of these variables and keep them the sa...