Resistance in Wires

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Resistance in Wires What is the purpose of a resistance wire? A resistance wire converts electrical energy into heat energy, and this is also its soul purpose. An example of a resistance wire is in a light bulb. The electrical energy is converted into heat, which then heats up the filament in the light bulb. This in turn creates the light needed. Resistance is a force, which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. The circuit itself can resist the flow of particles if the wires are either very thin or very long. e.g. The filament across an electric light bulb Predictions: The diameter of the wire will have an affect on the resistance as Ohms law states that ‘if the cross section of the wire is uniform then the resistance is proportional to the length and inversely proportional to the area of the cross section’. This is because the electrons have to squeeze together more to pass through a thin wire than they do to pass through a thick wire. [IMAGE] Length of the wire - The length of the wire will make a difference. This is because when you have a long wire, the electrons have to squeeze together for longer to be able to pass through the wire than they do in order to be able to pass through a short wire. I predict that the longer the wire, the greater the resistance. I also predict that if I had a 20 cm wire and a 40 cm wire, the 40 cm wire would have a resistance twice that of the 20 cm wire. Material of the wire - The type of material will make a difference because the electrons have to pass through the material. These electrons find it easier to pass through some materials than others. In this experiment I am going to use manganin, constanton and nichrome wire. I predict that the nichrome wire will have a higher resistance than the other wires.

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