Investigation into the Resistance of Wires

Aim:
I am trying to find out what affect changing the length of a piece of nichrome wire has on the current flowing through it. What happens if you change the thickness as well?

Diagram:


I will need the following equipment:
1x Ammeter
1x Voltmeter
1x Power supply
1x Variable resistor
1x Length of nichrome wire
1x Meter-rule
6x Connecting wires
1x Crocodile clip

My prediction is:
If the length of the wire is increased, then the resistance will increase. This is due to the electrons having a longer distance to travel and so more collisions will occur. Due to this, the length increase should be directly proportional to the increase in resistance.

Scientific knowledge:
I think this will happen because, if the length doubles, then the resistance will increase in direct proportion. The reason for this is; as electrons pass through the wire, the electrons hit the positive ions of the wire whilst making the journey from one end to the other, giving opposition or re...