Wire Resistance Investigation

Authors Avatar
Wire Resistance Investigation

Aim:

To investigate how the length of a wire can affect resistance.

Safety:

My main concern will be that if I turn the voltage up to high the wire could snap and hot metal could fly up into the eye. So I will wear goggles to protect my eyes.

Method:

First I will sellotape a piece of wire over a metre long to a metre ruler. Then will connect up a battery pack to an ammeter then the ammeter to the voltmeter then the voltmeter to the piece of wire using crocodile clips at 0cm then the negative clip is moved up and down the wire stopping at 10cm, 20cm and up to 70cm. Each time the length of the wire has changed I will read the ammeter and the voltmeter and record the results so from there I can work out the resistance which is R= V/I. Other variables will be kept constant like the voltage and the thickness of the wire. The experiment will be repeated three times using the same equipment.

Equipment List:

. Ammeter

2. Voltmeter

3. Power Pack

4. Power Leads

5. Two Crocodile Clips

6. Over 1 metre of wire

7. Sellotape

Fair Test:

I will make this test a fair test by keeping all the variables constant. By keeping the room temperature same each time and the same type of the wire the same each time. The wire will have to be pulled tight and tapped to both ends. Then I will carry out the experiment three times to get three sets of results. I can then work out the average and make graphs to show my results with a line of best fit.

Prediction:

I predict that if you increase the length of wire you increase the resistance. So if you decrease the length of a piece of wire you would decrease the resistance. This is because there are more atoms colliding with the electrons slowing down the electricity and causing a collision which produces energy called heat. The longer the wire the more colliding atoms there will be acting against the current producing a higher resistance.

Factors I have controlled:
Join now!


Material:

The type of material will depend on the amount of free electrons, and the amount of atoms within the wire will affect the resistance.

Length of wire:

Depending on the length of the wire the resistance will either be high or low. So if the wire was increased the electrons would have a longer distance to travel therefore more collisions could occur on the way.

Wire width:

If the width of the wire is increased there is more space for the electrons to pass through. So due to the increased space between ...

This is a preview of the whole essay