A small but measurable current of `1.2 xx 10^(-10) A` exists in a copper wire whose diameter is 3.0 mm. The number of charge carriers per unit volume is `8.49 xx 10^(28)m^(-3) m.` Assuming the current is uniform, calculate the (a) current density and (b) electron drift speed.

Answer

(a) `1.7 xx 10^(-5)A//m^(2); (b) 1.3 xx 10^(-15) m//s`