What is the resistivity of a copper wire with given dimensions and length?

AI Thread Summary
To calculate the resistance of a 31m long number 12 copper wire with a diameter of 2.053mm, the resistivity of copper is given as 1.72x10^-8 Ohm-m. The resistance can be derived using the formula R = ρ(L/A), where R is resistance, ρ is resistivity, L is length, and A is the cross-sectional area. The cross-sectional area for a circular wire can be calculated using A = π(d/2)². Users are encouraged to refer to resources like Wikipedia for further clarification on electrical resistivity and conductivity. Understanding these calculations is essential for solving related problems effectively.
freddy13
Messages
12
Reaction score
0

Homework Statement



A number 12 copper wire has a diameter of 2.053mm. Calculate the resistance of a 31m long piece of such wire. Use rho=1.72x10-8 Ohm-m for the resistivity of copper.

Homework Equations



This is the part that I am unsure of, all of my equations for resistivity do not really have anything along the lines of the given constants, nor can I see where one is derived. If it needs to be derived from something else, please post where you get it from so I can figure it out!
 
Physics news on Phys.org
freddy13 said:

Homework Statement



A number 12 copper wire has a diameter of 2.053mm. Calculate the resistance of a 31m long piece of such wire. Use rho=1.72x10-8 Ohm-m for the resistivity of copper.

Homework Equations



This is the part that I am unsure of, all of my equations for resistivity do not really have anything along the lines of the given constants, nor can I see where one is derived. If it needs to be derived from something else, please post where you get it from so I can figure it out!

You have a uniform cross section. Look here. http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Electric current and resistance question
Replies
2
Views
2K
A copper wire and an iron wire - Potential difference
Replies
6
Views
3K
Diameter of copper wire to have same resistance as equal length aluminum wire
Replies
2
Views
23K
Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit
Replies
6
Views
2K
How Does Temperature Affect Copper Wire Resistivity?
Replies
1
Views
1K
Long distance electrical transmission efficiency
Replies
2
Views
2K
Calculate Max Resistance for 2 Parallel Wires
Replies
7
Views
2K
Resistance of a Copper Wire with initial and final radius
Replies
8
Views
3K
Square copper wire loop within a magnetic field
Replies
3
Views
2K
Finding the voltage drop along a tapered wire
Replies
30
Views
2K

Hot Threads

Recent Insights

Back
Top