1. The problem statement, all variables and given/known data 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 2. Relevant equations I=Anev cross section = pi*r^2 3. 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?