finding length and diameter of copper wire!


by dev-hud
Tags: copper, diameter, length, wire
dev-hud
dev-hud is offline
#1
Feb16-10, 03:47 PM
P: 16
Suppose you wish to fabricate a uniform wire out of 1.0 g of copper (Density of copper is 8.93 x 10^3 kg/m^3). If the wire is to have a resistance of R = .5 ohms, and all the copper is to be used, what will

a) the length and
b) the diameter of this wire?



this has me tottally confuzed because i can not put together a formula to find lenght or the diameter of the wire. Help?
Phys.Org News Partner Science news on Phys.org
Cougars' diverse diet helped them survive the Pleistocene mass extinction
Cyber risks can cause disruption on scale of 2008 crisis, study says
Mantis shrimp stronger than airplanes
willem2
willem2 is offline
#2
Feb16-10, 04:39 PM
P: 1,351
You can compute the volume of the wire from the mass and the density.

If you know the diameter is equal to d, you can compute the length of the wire (from the equation for the volume of a cylinder)

If you know the length and the diameter, you can compute the resistance (resistivity of copper is [itex] 1.72 \cdot 10^{-8} \Omega m [/itex] )

The resistance will be a function of the chosen diameter d. Set this equal to 0.5 and you can find d
dev-hud
dev-hud is offline
#3
Feb18-10, 02:14 PM
P: 16
ok thank you.

so if i have a volume of 1.12 x 10^-4, and the equation for volume of a cylinder is (pi)(h)(r^2), i dont get how to computer the length if i do not have a height or a radius? and then i need the length and diameter to get resistance (given at 0.5), how do i get this into finding the diameter?

i am confuzed on what formula to use or how do use volume of a cylinder to get d??


Register to reply

Related Discussions
Diameter of a wire with length, resistance and resistivity Advanced Physics Homework 2
Fabricate uniform wire out of 2.1g of copper w/ 0.3 ohm resist. - wire diameter? Introductory Physics Homework 2
Diameter vs current rate of a copper wire Electrical Engineering 3
[SOLVED] Find the diameter of copper wire Introductory Physics Homework 13