Resistance of a wire

Resistance of a wire

Aim: To investigate how much resistance runs through 3 different wires at different lengths.

In This investigation I am going to use 3 wires, 2 of the same material e.g. (copper) and use 2 of the same thickness. I am trying to find out how much resistance runs through the wires. I am planning to use 2 Nickel (Nichrome) and 1 copper and the thickness’ 26 SWG and 34 SWG. Resistance is a measure of how hard it is to get a component (wire) at a potential difference or voltage and it is measured in ohms.
In the wire, you get resistance when electrons flow through it.
If the electrons are stopped or held up in any way then their flow will be decreased and current will decrease and the resistance will increase.
Electrons collide with metal atoms and they are slowed down making the resistance slow down so it will tell us how many metal atoms there are in the wire. The wire can also get warm/hot because of the flow of the electrons so this could potentially be unsafe as I will explain later. You can calculate resistance using ohms law but firstly you need to know the voltage and the current because you need to divide the 2 to find out the resistance.
I predict that if the wire is longer the more resistance there will be and the shorter the wire the less resistance because the electrons will not have as far to go meaning they will not have to collide with many metal atoms as they would have to if they travel further. There is an exception though and that is the variables what I will be explaining further on such as the voltage of the battery which would send more electrons out if the voltage is high. I believe this because metals are good conductors and its easy for electrons to travel through metals and also that it’s the same as if you calculated how much you could run through plants and leaves, you would hit less if you have to travel a shorter distance whereas if you travel further you will hit more. This is basically the same with the electrons except they hit metal atoms.
The method to use would be as follows:
Voltage meter
Wire (copper and nickel)
Connection wires
Meter ruler
Crocodile clips


Collect Equipment
Link wires from ammeter and volt meter to battery and then link them out again with crocodile clips.
Now connect your wire such as copper to the crocodile clips starting at 0cm going up in 10cms each time until 100cm measuring with a meter ruler.
Copy out results in a table as you go along as you look both at the ammeter and volt meter getting the readings.
Once you have measured the resistance in the wire, pack away equipment to correct place.

The measurements to be made are the specific wire and you are measuring to see how much resistance there is in the wire at different lengths. I will make these by using a meter ruler and crocodile clips measuring each different length from 10cm to 100cm. I will move the clips up to the certain length which up will be measuring at and read the readings off of the ammeter and volt meter. I will be measuring every 10 cm from 10cm to 100cm.

Fair test

I am going to make sure this is a fair test by using the same battery all the way through the experiments on all 3 wires. I will also measure at the correct lengths so that will be consistent throughout the experiments. I will make sure I use 2 wires of the same thickness and 2 of the same material (wire). This will make my results as accurate as possible and guide me to some good, correct results.


Length of the wire

Material of the wire e.g. copper or nickel

Thickness of the wire


Trial run

We done a trial run of setting up the equipment, measuring and recording. This all seemed to go well as we followed the guidelines and stuck to what we had planned to do. This is good to have a trial run because it may help avoid potential errors and slip up points where in the real tests we would be able to correct.