1. Resistance of a Wire Coursework Practical Investigation
Recap
Make sure you read all of this Powerpoint
presentation carefully before you start
your final investigation write up.

2. What the investigation is about.
Your task was to find out how the length of a wire affected its resistance.
Most of the resources and information you need are in the Science shared area of the network.
Before you started the experimental part you found out about the scientific reasons for resistance.

3. This is the worksheet you were given to help you research the science
This is the worksheet you were given to help you research the science. You will need the answers to the questions when you write your investigation report.
There is a copy of this worksheet in the Science shared area of the network. It is called
A MODEL FOR RESISTANCE OF A WIRE
There is also a Powerpoint presentation with all the answers to the worksheet.

4. The next thing you did was to choose a circuit to use to get your results.
Watch the Powerpoint presentation “R of a wire circuit choices” for a reminder of the circuits you could choose from.
Take note of the advantages and disadvantages of the circuit you used. It is important to explain why you choose the circuit you used.
(but it’s better not to mention the grades it allows you to get.)
You were then given chance to try out your circuit and decide on the different lengths of wire you were going to test.
This is what we refer to as “rough trials” or “preliminary work”.
You also had to decide on how to make the experiment a fair test.
This means finding out what other factors (things) could affect the resistance of the wire and making sure they didn’t change.
Finally you had to make your results as reliable as possible.
This means repeating readings to see if/how much they change.
What do you do if you have 3 values for the resistance of the same length of wire?

5. Look in your practical assessment plastic wallet for:
A checklist of all the things you need to do to produce a complete report,
The mark scheme that will be used to mark your investigation
You will see that, to get full credit for your work:
You need to write up the investigation in your own words. You can’t give in sheets that I have produced and you have just filled in.
The table of results must be one you have drawn out yourself. You can use Excel or Word but you can’t just cut out and stick the one you were given.
You should have drawn your own graph, not used the pre-printed one with the axes already labelled.
You need to explain your results using scientific information about resistance from your answers to the “A MODEL FOR RESISTANCE OF A WIRE” sheet.
You need to identify any outliers on your graph. If there aren’t any, say so in your report.
You need to evaluate your experiment. Try to give reasons for any outliers and suggest improvements.

6. A complete report has 5 sections
An introduction. In this section you state the aim of the investigation and summarise the basic scientific theory.
The plan. This section includes your labelled diagram and a method saying how you did the experiment. It should include how you made the experiment a fair test, how you made it as reliable as possible and any precautions you took to improve safety and accuracy.
The results. – simply your table of results.
Analysis. This includes the graph and your conclusions. It must state what your results show in as much detail as possible and attempt to explain the results using the scientific information you have found.
Evaluation. This section looks back at the experiment and discusses how well it worked, how much you can tell from your results and how the experiment could be improved.
Don’t forget to check on the marks for presentation. For example you can lose marks by leaving out labels/headings on graphs and tables. You also gain marks by giving values to an appropriate number of decimal places.