Apparatus: Meter Ruler- Safety Goggles- Cell- Wire- Crocodile Clips- Ammeter- A Voltmeter- V Plan For the following experiment my plan will be to firstly wire up all the appliances to create a circuit then I will predict whether the resistance increases or whether it does not increase while the wire increases. I will carry out the experiment increasing the length of the wire by 10cm each time I will then take down the results of the voltage, current.
To measure the voltage I will use a Voltmeter to measure the Voltage, to measure the length of the wire I will use a meter ruler and finally to measure the current I will use a Amp meter. After gaining these results I will work out the resistance using this formula: Resistance=Voltage/Current Having gaining the results I will write them up in a table from which I will plot the graph to support my results Then after drawing the graphs I will come to my conclusion, in my conclusion I will conclude what happened in the experiment and I will say whether my prediction is right.
I will then come on to the evaluation of my experiment. Prediction My prediction is as the Length of the wire increase by 10cm the resistance will get affected making it to increase. The factors which may affect my experiment are firstly the cell(Battery) which may ran out or cause a defect, The voltmeter or ammeter may show the wrong Voltage or current and there also could be a wrong connection being made connecting the circuits. There also could be a user fault and they may measure the wrong length of wire.
The factors which need to be controlled are to firstly to get a good working battery and them some healthy working wires. You need to make sure u connect the circuit correctly and also you need to make sure you measure the correct length each time. I will also keep the same temperature to make sure the experiment is even I will do this by using a thermometer to make sure the temperature is constant. I will be using Room temperature.
Work Done By- SaNjE Balendra Table of results (Thin Wire) Length Voltage Current Resistance Here is the table of results for my second experiment in which I used a thick wire Table of results (2nd Thicker Wire) Length Voltage Current Resistance Here is the table of results for third and final experiment Work Done By- SaNjE Balendra Conclusion Having done my experiment I have come to my conclusion.
In my experiment I have found out that as the length of the wire increases the resistance increases. This is because as the length of the wire increases it causes the current and voltage to increase which means the resistance increases as well resistance is equal to voltage divided by current. The resistance increases because there is more sufficient surface area which means the can atoms to collide, when the thickness increases it causes the resistance to decrease as there is a lot of surface area so there will be less collision.
Evaluation The experiment proved to be a success and it went very well although it could be improved by trying other lengths, different voltages but also a different type of wire to be able to compare the resistance difference this would make a more interesting experiment. I feel overall my results were quite precise. You can see my results were accurate looking at all 3 of my graphs, which shows a straight line through most of the points apart from one or two which are on the line or not very apart from the line.
The 2 points on the (thin wire) which was not close to the line was a Anomaly but it did not effect the gradient in the graph. In my experiment the places I think I made the most errors in the experiment was measuring the length of the wire as it was hard to measure the wire keeping it straight and then holding a meter wire to measure it. I can improve on how to measure the wire by using more than one person to either help me or do the experiment with me, I can also improve by being sensible and being focused on my work and on what am doing.