Resistance Of Wire Investigation (length)

Essay by liamalagloo January 2006

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Plan

In this investigation I am going to investigate how the length of a piece of wire affects its resistance. The following are all variables that affect the resistance of the wire:

- The thickness of the wire is a big variable as the thinner the wire the bigger the resistance. This is because the current has to squeeze through a thin wire, but it can easily flow through a thicker one.

- The length of the wire is also a big variable as the longer the wire the more atoms the electrons will hit making it a bigger resistance.

- The temperature of the wire effects the resistance because as it gets hotter the atoms inside it vibrate more which increases the chance of the electrons hitting them so the hotter it gets the more resistance it has.

- The type of wire can also affect the resistance because different metals have different amounts of free electrons and the more the smaller the resistance is.

These variables will all effect my investigation but I am going to use the length of the wire as the variable and keep the others the same to make it a fare test.

I predict that the longer the piece of wire, the greater the resistance will be. This is due to the idea of the free moving electrons being resisted by the atoms in the wire. In a longer piece of wire, there would be more atoms for the electrons to collide with and so the resistance would be greater. The relationship between the wire length and the resistance should be directly proportional. This is because in a wire twice the length of another wire there would be double the amount of atoms causing the resistance.

An example of this would be...