150 1020 electrons flow through a cross section of a 340mmd

1.50 × 10²⁰ electrons flow through a cross section of a 3.40-mm-diameter iron wire in 5.50 s . What is the electron drift speed?

Solution

current: I = nAvq

Current I = 8.5*10²⁸ x x ( 1.7 x 10^-3 )² x v x 1.6 x 10^-19

[1.5*10²⁰ x 1.6 x 10^-19 ]/5.5 = 8.5*10²⁸ x x ( 1.85 x 10^-3 )² x v x 1.6 x 10^-19

therefore, electron drift speed is, v = 2.985 x 10^-5 m/s