How Thickness and Length Affect the Resistance of a Wire

How Thickness and Length Affect the Resistance of a Wire

I plan to investigate how the length and thickness of a wire affects

the resistance. I plan to do this by keeping the voltage the same by

using a variable resistor and measure the current when varied lengths

and thicknesses of wire is in a circuit

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Variables

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There are a few factors that can affect the resistance. These are;

* Temperature

* Thickness

* Length

* Material

I plan to change the length of nichrome wire at intervals of 10cm's. I

also plan to investigate how the thickness of a wire affects the

resistance. I plan to do this by measuring different lengths and both

thicknesses of wire and comparing results. In my experiment, the

voltage, material and temperature will remain constant.

Prediction

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I predict that the longer the wire is the more resistance there will

be. In relation to the thickness, I predict that the thicker nichrome

wire will produce less resistance. I assume that as the length of the

wire doubles the resistance will also, therefore the current halves,

this means I think that resistance is proportional to length and will

show a straight line on a graph.

I predicted that the resistance decreases as the wire increases in

thickness. I will be using a wire that is double the thickness of the

previous one, therefore has double the cross-sectional area. I believe

that the current will increase as the thickness of wire increases,

this is because when the cross-section increases the amount of

electrons also increases, wh...

... middle of paper ...

...a thermocouple and then connect it to a circuit and record the

resistance.

Material:

To do this, I would set up the experiment the same as with the

thickness investigation. In order to investigate how material changes

the amount of resistance, I would firstly find different materials e.g

copper wire, nichrome wire etc and conduct a preliminary test to see

if the different materials had enough difference of values to show the

effect of the material on resistance. If all values of the materials

were similar, I would be persistent in finding materials that had

significantly different readings. When I had found suitable materials,

I would connect the apparatus the same as Diagram 1, and take readings

for each material separately, making sure not to heat the wire as it

may cause the wire to effect the final results.