# physics

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#1
im doing an experiment on how the diameter of a wire affects its resistance

i need to make a list of factors which may affect my experiment and WHY

thankyou
0
17 years ago
#2
(Original post by sarah_999)
im doing an experiment on how the diameter of a wire affects its resistance

i need to make a list of factors which may affect my experiment and WHY

thankyou
temperature will affect the resistance (more ionic agitation will increase the resistance).
0
17 years ago
#3
(Original post by sarah_999)
im doing an experiment on how the diameter of a wire affects its resistance

i need to make a list of factors which may affect my experiment and WHY

thankyou
asumming ur doin A'level have u met the resistivity equation?
0
17 years ago
#4
(Original post by sarah_999)
im doing an experiment on how the diameter of a wire affects its resistance

i need to make a list of factors which may affect my experiment and WHY

thankyou
Temp. ;
the measurement of diameter, length, current, p.d.
0
17 years ago
#5
(Original post by sarah_999)
im doing an experiment on how the diameter of a wire affects its resistance

i need to make a list of factors which may affect my experiment and WHY

thankyou
Temperature - The greater the temperature and the heat exposed from the wire, then the greater it's resistance will be.

Voltage - You should determine a suitable voltage for your experiment. The greater the voltage and the longer the duration of the voltage being supplied (energy) then the greater the current that flows through the wire. In turn, this would cause the wire to heat up and hence this would increase resistance the longer the duration of the experiment.

Length of the wire - The greater the length of the wire, the greater its resistance.

Resistivity Of Wire - The resistivity of wire is a property that indicates the natural resistive properties of wire (assumed at room temperature) against electrical current. Wires will have different resistivities based on their conductive nature. i.e.) copper will naturally not have a resistivity value as great as some other metals because it is a metal that conducts electricity quite well.

A formula used to calculate the resistivity of a material is:

R = (pL)/(A)

Where:

R = Resistance
p = Resistivity
L = Length
A = Cross-Sectional Area

Hence, there is a way you could prove the effect that diameter has on resistance of the wire:

Area = Pie * r^2
Area = Pie * (d/2)^2

Hence: R = (pL)/[Pie * (d/2)^2]

Therefore you can now mathematically show the affect that increasing diameter has on the resistance of the wire.

As with all scientific experiments, you need to control these factors in order to test the single variable that you choose (diamater in this case). Otherwise you do not know whether the variable you test has a direct and conclusive effect on what you observe/discover in the experiment.

Hope this helps.
0
17 years ago
#6
(Original post by elpaw)
temperature will affect the resistance (more ionic agitation will increase the resistance).

You may a learn a thing or two!
0
17 years ago
#7
(Original post by bono)

You may a learn a thing or two!
You wish
0
17 years ago
#8
I think this is at GCSE y10 level- adding in the equation may just make it confusing... though I did 2 factors in mine and created that equation from my findings- so actually, it may be useful.

btw did you just reply to yourself or is it a typo?
0
17 years ago
#9
(Original post by r316)
I think this is at GCSE y10 level- adding in the equation may just make it confusing... though I did 2 factors in mine and created that equation from my findings- so actually, it may be useful.

btw did you just reply to yourself or is it a typo?
I was sarcasticly saying that I was teaching a thing or two to Elpaw.

Ironically, he's an oxford physicist!

EDIT: I was talking AS Level standard, so it would be too advanced for your current coursework.
0
17 years ago
#10
its Pi not Pie
0
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