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The resistance of a wire in a circuit essay

For example, in table 1 for the first current in 100cm, it was 1. From these results I will now create a line graph from the average resistance.

Conclusion Graph-Analysis From analysing my graph, I can clearly see as the dependent variable increases the independent variable also increases. This shows a strong positive correlation, as the trend line is positive. As the length of wire increases, the resistance also increases. This shows that the more wire there is, the higher the resistance.

This is because the longer the wire, the more times the free electrons will collide with other free electrons, the particles making up the metal, and any impurities in the metal. Therefore, more energy is going to be lost in these collisions as heat. Whereas when there is less wire, there are fewer electrons to collide with each other, or particles of the copper or any impurities in the copper.

Therefore the resistance is low when there is less wire.

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The line graph shows the line of best fit of a strong trend of a straight line so the length of the wire is shown to be directly proportional to the resistance — double the length and the resistance doubles.

From my prediction, my graph and tables support my prediction. As I predicted that as the length of wire increases, the resistance will also increase. This is because the current will have more wire to pass through so the resistance will be high, whereas when there is less wire, the current can flow through easier, having a lower resistance.

My line graph shows my prediction was correct as the independent variable increases, which is the length of wire; the dependent variable also increases as the resistance increases. There maybe a few anomalies, but most points go through the line of best fit, with the other points close to it.

Evaluation From evaluating my evidence, I have come to a conclusion that the length of wire does affect the resistance. This is shown by my tables as the length of wire increases, the resistance also increases.

Factors affecting the resistance of a wire Essay

My graph also supports this, as it is a strong positive correlation as one variable increases, the other variable also increases. I tried to make my results as accurate as possible by firstly, making sure that it was a fair test as stated earlier in the coursework.

Everything was adhered to so as the results could be accurate and concise. The temperature was kept the same, the width of the wire was kept the same and also the type of wire was kept the same. However, I feel I could have made by results more accurate and reliable to support my prediction and aim. Because I may have a made a few mistakes such as the way the crocodile clips were moved, could have hindered my results, which were the movement of the clips. The voltmeter and ammeter sometimes did not work properly so I had to change them and get a new one, which could have affected my results.

  1. Resistance occurs when the electrons travelling along the wire collide with the atoms of the wire.
  2. A closed circuit is one that is complete, with good continuity throughout.
  3. PredictionI predict that as the length of the wire decreases so will the resistance. Therefore, more energy is going to be lost in these collisions as heat.

However, as I carried out this experiment on different days, the room temperature may have been different, which may have also affected my results and also hindered my experiment, as there was an anomaly in test 1. I had difficulties in taking some results as power packs made the wire dangerous, so as then the results could not be accurate enough as the temperature of the wire may affect the resistance.

To improve this investigation, I could have used a variable resistor or rheostat, which is used to vary the current in a circuit. As the sliding contact moves, it varies the length of wire in the circuit. To make my results more accurate and to also improve this investigation, I could have used a more accurate digital ammeter and voltmeter, so as the results will be exact and will help me to get a more accurate result. I could have also used a well calibrated ruler, so as I could have measured the exact length I wanted, as I may have made errors with this.

  1. It can be said that conductors have low resistance and insulators have very high resistance.
  2. I will range my measurements from 10cm to 100cm going up in lots of 10cm as this will give my a good indication of the resistance in a wire. Resistance is measured in ohms R , potential difference in volts V and the current in amperes I Key factors.
  3. The current that we pass through the wire is to be kept the same, also. The line graph shows the line of best fit of a strong trend of a straight line so the length of the wire is shown to be directly proportional to the resistance — double the length and the resistance doubles.

To make and investigate the resistance further, I should have used different wires and tested them fully. Whereas in the preliminary I took only one reading of three different wires, as do that I could familiarise myself with the investigation. I could have also changed such aspects as mentioned in the fair test section, such as changing the temperature to find out also if temperature in any way affects the resistance.

I could have also changed and varied the width of the wire, as I have already found out that length of wire does affect resistance and whether the width also affects it.

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I could have also tested out different wire such as nickel chrome, Constantine as in the preliminary results to find out different resistances of different wires. I could have also, to make the investigation more accurate by measuring the temperature of the wire to find out whether different lengths of wires have different temperatures so as this may affect the resistance Overall, I feel the investigation was a success, and I believe I have achieved my aim of finding out how the length of wire affects the resistance.

This is, as the length of wires increases, so does the resistance also increases, due to more electrons colliding with each other.