Investigating the effect of length on resistance is common but some students may wish to investigate the effect of the thickness of wire. Results Below is a table of my results Table 3. I could have considered using a new piece of wire each time in order to regulate the temperature more stringently.
Note the reading on the ammeter. There are possible sources of error that might have led to inconsistent results, such as a kink in the wire.
As shown by the equation, knowing the length, cross-sectional area and the material that a wire is made of and thus, its resistivity allows one to determine the resistance of the wire. Selection of reels of different wires e. Those materials with lower resistivities offer less resistance to the flow of charge; they are better conductors.
However, due to my line of enquiry, I will only change the length of the wire. This discharges the cell rapidly and can make it explode.
Use the Resistivity of a Material widget to look up the resistivity of a given material. In addition, I will make sure I turn the power pack off after each reading.
Again, I will record the voltmeter and ammeter readings and turn off the power pack. I will try to make this investigation as accurate as possible. Graph Graphing these results shows a nearly straight line, illustrating a strong positive correlation between length and resistance, which is consistent with my prediction.
If short lengths of wire are used with relatively high currents and voltages, then significant electrical heating may also occur. This was because I could plot a graph and show the general trend. It could overheat and thus lead to the risk of fire.
On the other hand, the thinner gauge wire can support less current owing to its larger resistance; it is used in circuits which are protected by Amp fuses and circuit breakers.
The standard metric unit for resistance is the ohm, represented by the Greek letter omega. The amount of guidance will depend greatly upon the teaching group. Thus, gauge wire has a wider cross section than gauge wire. Teaching notes 1 Use fine gauge wires. A Amp circuit used for wall receptacles should be wired using gauge wire and a Amp circuit used for lighting and fan circuits should be wired using gauge wire.
Type the name of the material and click the Submit button to find its resistivity. However, I think that unless I had specialist equipment the results would be distorted because the wire would eventually get very hot.
Check Your Understanding 1. Investigating the resistance of wires Class practical A simple investigation of the factors affecting the resistance of a wire. The colors reveal information about the resistance value.
Most resistors have stripes or bands of colors painted on them. I will also control, using the power pack, how many volts pass through the wire. I will also ensure that there is a clear indication that the power is isolated by means of a switch and an L.
Consistent with the discussion above, this equation shows that the resistance of a wire is directly proportional to the length of the wire and inversely proportional to the cross-sectional area of the wire.First, the total length of the wires will affect the amount of resistance.
The longer the wire, the more resistance that there will be. There is a direct relationship between the amount of resistance encountered by charge and the length of wire it must traverse. AIM -To determine resistance per unit length of a given wire by plotting a graph of potential difference versus current.
APPARATUS REQUIRED 1. A wire of unknown resistance 2.
Fig -1 Circuit to find the relation between current (I)and potential difference(v). Class practical A simple investigation of the factors affecting the resistance of a wire. and the ammeter, with a 30 cm length of one of the wires closing a gap between two crocodile clips.
Note the reading on the ammeter. This experiment can be used as a more open-ended investigation. Students can select the variables, the ranges of. Apparatus and materials Ammeter, 0 to 1 A, DC Voltmeter, ( V), DC Power supply, low voltage, DC Lamp (12 V, 6 W) in holder Resistor (approx 15 ohms, 10 watt) Various other components Measuring resistance with a voltmeter and an ammeter.
Apr 19, · An Investigation Into the Resistance of a Wire - GCSE Physics Coursework. Updated on December 30, Luno more. I have done a preliminary experiment to help me decide the best way to do my investigation. The results will help me make predictions, as well. I will investigate the resistance of a wire in relation to its mi-centre.coms: Experiment to determine the resistance of a wire.
From TecHKnow Wiki. Jump to Procedure When handling the wires avoid stretching them or deforming by kinking. this introduces local restrictions that will For each wire plot a graph of resistance (y-axis) against length. The resistance of a wire is given by the equation: R = ρ x l/A.Download