Resistance of a Wire Investigation

Preliminary Investigation:

Aim: To investigate the main problems with my main experiment and to see how to resolve these.

Preliminary Method:

1. Setup Equipment

2. Make Circuit with the set length of wire

3. Draw Results table

4. Record Results

5. Change the lengths of wire and do same steps 2 more times.

Preliminary Equipment:

* Metre Ruler

* Metre length Of wire

* Voltmeter

* Ammeter

* Power Unit

* Sellotape

* Paper, Pencil

Preliminary Diagram:

Preliminary Investigation:

I have decided to do a preliminary investigation. This preliminary will help plan my main experiment. I will choose 3 lengths, 10cm, 50cm and 100cm. These lengths are reliable as they don't jump lengths too much. One small, medium and large length. Here I will use a simple circuit and study the results, to see they are reliable. This investigation will mainly show the accuracy and how reliable my main investigation is, changing anything that is unreliable and needs corrected. I have learned that it is important to use a multimeter because it shows an accurate digital reading of the resistance and I don't have to work out the resistance manually which can give me a fairer test due to possible mistakes with calculations. It will also cut down the amount of components in the experiment which will make the experiment more reliable as less resistance will be caused from the components rather than the wire. It is also very important to keep the most important variable, current the same throughout the whole investigation. The heat in the wire from the current can cause the wire to affect my results as the ions gain kinetic energy causing them to have a higher collision rate. The multimeter should be a solution to this, as it uses a very small current thus