Resistance of a wire

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GCSE Physics Coursework

Resistance of a wire

Investigation

To find out how the resistance of a wire is affected by the length of the wire.

Metals conduct electricity because the atoms in the metals do not hold onto their electrons, and they create free electrons. The amount of free electrons depends on the material, and more free electrons means that a better a conductor it will be, because it has less resistance. Silver would have more free electrons than iron so that makes it a better conductor. Resistance is made from energy, which is lost as heat. Collisions between the free electrons and the particles fixed in the wire change some of the energy into heat. Ohms law states that a current through a wire at the same temperature is proportional to the potential difference (the voltage). This means that the resistance of the wire conductor is the same if the temperature also stays the same. The resistance of a metal increases as its temperature increases, and this is because at higher temperatures, the particles of a wire are vibrating, faster, which increases the chances of them colliding with the free electrons.
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Planning

Here are some key factors that I will be using in this investigation:

Length of the wire

Diameter of the wire

Materials of wire

Voltage

Out of these key factors, only one of them will be changed and it will be length, all the rest of them will be kept constant.

The diameter of the wire is important because if the diameter is thinner, the resistance will be larger The material of the wire is important because different materials Will conduct differently The length of the wire is important because ...

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