Question

A copper wire carries a current of density Assuming that one free electrone corresponding to each copper atom,evalute the distance which will be covered by an electrone during its displacement along the wire

Answer 1

By definition

nev_d = j (where v is drift velocity, n is number density of electrons.)

$\tau =\frac{l}{v_d}=\frac{nel}{j}$

So distance actually travelled

$S=\left|v\right|\tau =\frac{nel\left|v\right|}{j}$