Measuring the Resistivity of Copper Wire of Different Lengths
In this report I will be writing about the experiment I will conduct on copper wire of different lengths. The dependent variable I will be measuring is the resistance of the Copper wire. To do this experiment, one needs to obtain measurements with a high degree of accuracy, taking care of the equipment they use and measuring each value to a certain degree of accuracy for all results. The problem with measuring the resistivity of Copper wire is due to the properties of copper as a material. Copper naturally has a low resistance due to it being a superconductor, meaning that it only has a resistance of minute amounts. As it has this property, it is important to use a copper wire…show more content… In the experiment I am conducting, I will be measuring the p.d. to a resolution of 0.001V using the 2V range on the multimeter. Having the resolution to this degree of measurement ensures that I get a voltage reading to 3 decimal places increasing the accuracy of the reading and allowing me to obtain a closer value to the true value. The accuracy for the ammeter has been published as being ±1.2% of the reading + 1 LSD for the range (200mA) and resolution (0.1mA) I will be using for the current. This means that the value I will record will be 1.2% of the true value of the current +0.1mA. I am using the 200mA range rather than the 20A range because the resolution of the result is greater than that of the 20A range. This will record a more accurate result which reduces the uncertainty in my results. Similarly the range I will use on the voltmeter which is at 2V has an accuracy of ±0.5% of the reading + 1 LSD, which is even more accurate.
Another factor which can affect the resistivity of the result is the temperature of the copper wire. This can affect the resistivity by changing the value of the resistance to make the resistance less proportional to that of the length of wire. Normally the resistance of a wire will increase as the length of the wire increases due to their being more atoms in the wire for the electrons to pass by in order to get the through the entire length of wire. As the increase in resistance α