Investigating the Resistance of Wires :: Papers

Investigating the Resistance of Wires Aim To investigate how the diameter of a constantan wire will prompt its resistance and hence the current flowing through it. Prediction I predict that the thicker the diameter the less resistance there will be. Reason In a metal, some of the electrons are free to move between the ions, to form a sea of electrons around the positive metal ions. Metals that are good conductors generate more free electrons and therefore these electrons move easily around the positive metal ions. However in metals that stimulate fewer free electrons, the ions act as obstacles to the flow of electrons and therefore the wire has resistance. The current becomes stronger with the more electrons that flow through a wire in one second. As the diameter increases the electrons will have more available routes between the ions to pass through per second, making the electron flow greater hence the current becoming stronger. See figures 1 and 2 IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGE In a larger diameter, there IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEFigure 1 are more routes for free IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGE electrons to travel IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGE through. IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGE In a smaller diameter, IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEFigure 2 there are fewer routes IMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGEIMAGE for the free electrons IMAGE to travel through. Plan I will set up a circuit consisting of a cell, ammeter, voltmeter and 50cm of constantan wire. The diameters I will give are as follows. 0.56mm, 0.43mm, 0.38mm, 0.32mm, 0.27mm and 0.20mm. I wi ll measure these diameters with a micrometer. I will take three readings of the current and potential difference for each disparate diameter of the wire and take an average for V (potential difference measured by a voltmeter) and I (current measured by an ammeter) in order to spend a penny the most accurate results possible. I will then plot these results in two graphs one plotting V against I and another plotting the average resistance (using ohms police force R=V/I) against the diameter.