A rise in temperature causes ions inside the metal to vibrate more causing electrons to collide into them this builds resistance; therefore the electrons find it harder to get through the wire.
The greater the temperature the greater the resistance because electrons are colliding more causing friction. Therefore the relationship between them is directly proportional. The thicker the wire the easier it is for the electrons to go past. The thinner the wire, the smaller the area the electrons have to pass through. This means that they collide more often and as a result sacrifice more of their energy to the neighbouring particles in the wire. The cross section of the wire and the resistance is inversely proportional this means that the greater the thickness of the wire the lower the resistance.
The longer the wire the more ions there are for the electrons to get past. Energy has to be used to push current through a wire. If the electrons have to travel further in a long wire, therefore more energy will be needed. The relationship between resistance and the length of the wire is directly proportional this means that the greater the length of a wire the larger the resistance.
The variable I have decided to use is the length of wire because I believe that it is the easiest to control to my ability. I predict that as the length of the wire increase so does the resistance. This is due to the idea of the free moving electrons being resisted by the atoms in the wire. To make sure we have a constant current in order to take an average measurement.
I will measure the resistance of 8 different lengths of nickrome wire using a tape measure. I shall join the multimeter in series with a Direct current power supply i. The multimeter is better to use because of the larger currents and because the readings are given to 2 decimal places.
I shall then proceed to connect a 50 mm length of nickel-chrome wire, which shall be measured using a tape measure, he output from the ammeter. Feb 11, 8.
Feb 11, 9. Gokul , Feb 11, Feb 11, Though im only studying my second year of A-Level Physics, i tried to keep the investigation solely on metals as most metals conduct electricity and I can measure their resistivity. But the suggestion made by Gokul about different temperatures is a very good idea and i am willing to give this a try. Though at this moment in time i have no idea on how to measure the resistivity of non-metals. Well what i explained in my previous post was about a preliminary experiment i had done last year and the class was warned that there are massive errors.
In that experiment there was a heater immersion which stuck inside the middle of the cylindrical block of aluminium connected to a power supply. There was a little hole where the thermometer would sit to measure its temperature.
It did not measure the average temperature of the block itself. This was the way the teacher told us to do. The block has a layer of thick cardboard wrapped round the outside, not sure what was on the bottom but there wasnt much we could do with the top as the immersion heater and the thermometer stuck out. This method was the heater circuit you mentioned. Though i would research about the calorimetry method you suggested.
Are these used in chemistry?? I remember from AS chemistry about calorimeters and a great long accurate thermemoter like device capable of measuring the temperature in a great amount of accuracy. Its a bit of a bad time now to find out what my school has as its our one week holiday. It was set yesterday and the planning stage must be finished in a week and its one month for the practical, analysis and evaluation.
If i am able to plan the experiments for both metals and non-metals especially the resistivity part then i will include it in and see what the teacher thinks about this. Your concern that a non-metal will have an impossibly high resistance is understandable, but Recall the formula for resistance: This is not hard to do: This way, the cirrent will not make use of the full area.
For another suggestion on a metal to use: I recommend stainless steel. It has a considerably poor thermal conductivity and will make for an interesting data point. My suggestions for materials will update as I get better ideas: Feb 12, I understand what you are saying Gokul The length and thickness of the non-metal should be small in order for its resistivity to be measured.
I know that by using leads as connectors to conencted the various devices together to form a circuit, the actual physical conenctions made do have little resistance and i think i will include that in the coursework and there isnt much i could do.
And there is one part about fair testing. If i make the non-metals significantly small, do i have to make the other materials the same length and thickness. Gokul , Feb 12, Feb 16, Feb 22, From looking at the equipment my school can provide, it seems i would have to measure the specific heat capacity of the blocks using the heater circuit method.
At the moment i would have to use the same block to measure the resistivity as well. I am thinking of a solder method for this and whether it is appropriate? I will use a thin metal sheet of copper or another metal and solder it to the bottom of the block. I will have to measure its resisticity in some way by passing a current though it which at the moment i have no idea on how to do.
I will have to obtain a lot of results and hopefully plot a scatter graph with specific heat capacity and resisivity as the axis. Is this a valid method? Feb 24, Gokul , Feb 24,
Nov 21, · Resistance Wire Coursework Help Sheet. An Investigation Into the Resistance of a Wire – GCSE Physics I will investigate how the length of the wire affects the resistance. I have done a preliminary experiment to help .
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Physics GCSE Coursework:Factors affecting the resistance of a wire When an electric current passes through thin nichrome or tungsten wire, the electrons cannot flow easily. They collide with the atoms in the wire, which vibrate more quickly. The relationship between resistance and the length of the wire is directly proportional this means that the greater the length of a wire the larger the resistance. My chosen variable: The variable I have decided to use is the length of wire because I believe that it is the easiest to control to my ability.
Apr 19, · Free GCSE physics coursework essay. STEM» Physics; An Investigation Into the Resistance of a Wire - GCSE Physics Coursework. Updated on December 30, Luno more. Contact Author. Introduction. In this article I will investigate what affects the resistance of a wire. I have done a preliminary experiment to help Reviews: - GCSE Physics Coursework - Resistance of a Wire Coursework Resistance of a Wire Task To investigate how the resistance of a wire is affected by the length of the wire. Theory What is resistance. Electricity is conducted through a conductor, in this case wire, by means of free electrons.