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Resistance of copper wires

  • Thread starter zelda1850
  • Start date
66
0
1. Homework Statement

a copper wire of length of length L and cross sectional area A has resistance R. A second copper wire at the same temperature has a length of 2L and a cross sectional area of 1/2 A. what is the resistance of the second copper wire?

2. Homework Equations

R = pL/A

L = 2
A = 1/2
p = how do i find p

3. The Attempt at a Solution

p stand for resistivty but how do i know it in this problem
 

rl.bhat

Homework Helper
4,433
5
Re: resistance

In the relevant equation replace L by 2L and A by A/2 to get new resistance.
 
66
0
Re: resistance

oh should the answer come out to be 1R
 

ideasrule

Homework Helper
2,266
0
Re: resistance

yes.
 

rl.bhat

Homework Helper
4,433
5
Re: resistance

oh should the answer come out to be 1R
No.
New resistance R' = ρ*2L/A/2 = .......?
 
66
0
Re: resistance

i think p would be 1.72 x 10 exponent -8 since it is on copper
so i do 1.72x10 exponent -8 * 2 m/ 2 a is that the right equation?
 

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