Question

A 14.0 gauge copper wire of diameter 1.628 mmmm carries a current of 12.0 mAmA . Part A What is the potential difference across a 2.25 mm length of the wire? VV = nothing VV SubmitRequest Answer Part B What would the potential difference in part A be if the wire were silver instead of copper, but all else was the same?

Answer 1

Answer:

a) 2.063*10^-4

b) 1.75*10^-4

Explanation:

Given that: d= 1.628 mm = 1.628 x 10-3 I= 12 mA = 12.0 x 10-8 A The Cross-sectional area of the wire is:  

$A=\frac{\pi }{4}d^{2} \\=\frac{\pi }{4}*(1.628*10^-3 m)^2\\=2.082*10^-6 m^2$

a) The Potential difference across a 2.00 in length of a 14-gauge copper  

   wire:

  L= 2.00 m

From Table  Copper Resistivity $p$= 1.72 x 10-8 S1 • m The Resistance of the Copper wire is:

$R=\frac{pL}{A}$

   =0.0165Ω

The Potential difference across the copper wire is:  

V=IR

 =2.063*10^-4

b) The Potential difference if the wire were made of Silver: From Table: Silver Resistivity p= 1.47 x 10-8 S1 • m

The Resistance of the Silver wire is:  

$R=\frac{pL}{A}$

   =0.014Ω

The Potential difference across the Silver wire is:  

V=IR

 =1.75*10^-4