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...
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...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.
I also decided to use a wooden block to keep hold of the wire, because
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Since all metals have different densities and makeups I think that the heat capacity will greatly vary. The makeup of iron is very different than aluminum so the heat capacity will be quite different. Also, a lot of metals are not completely pure and that will also have some effect on the heat capacity.
equation V = IR. V - volts, I - current and R - resistance. I plotted
of the atoms, so if there are more or larger atoms then there must be
Instead of using a metal I decided to use a thermistor as it can be
Investigating the Effect the Thickness of a Wire has on Its Resistance. Equipment:.. Nickel Wire cut into 10 pieces of 30cm length (Ruler, Pliers). Two crocodile clips Five Pieces of Wire Power Source Variable Resistor Ammeter Volt Meter Method: The.. =
This is know as resistivity. The factors I can investigate are : Ÿ Temperature Ÿ Length Ÿ Cross-sectional area/width Ÿ Material (resistivity) The factor I shall investigate is the length of a wire. Background Knowledge Resistance is when electrons travelling through the wire are impeded by the atoms within the wire. Since the electrons are charge carriers when they collide with the atoms in the wire less pass through.