- #1

Johnahh

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## Homework Statement

a wire carrying a current of 3.2A has a radius of 1.2mm. the material of the wire has 2.5x10^25 free electrons per cubic metre. the elementary charge is 1.6x10^-19

## Homework Equations

I=Anev

cross section = pi*r^2

## The Attempt at a Solution

pi*0.0012^2 = 4.5x10^6

3.2/4.5x10^6*2.5x10^25*1.16x10^-19 = 0.1777 recurring

I am sure this is not correct as it seems to fast, I have seen some examples and they are more like 2.8x10^-4 m/s

Am i supposed to make 2.5x10^25 into 2.5x10^19 for mm^3 instead of m^3?

Any help please?