Question

A copper wire with a cross-sectional area of 1.2x10^-6(m^2) is connected into a circuit with a constant voltage source. The current in the wire is 1.5mA. The concentration of free electrons in copper is 8.7x10^28(m^-3). Calculate the drift velocity in m/s of electrons in this wire.

Where;

e = 1.6x10^-19
I = 1.5x10^-3
N = 8.7x10^28
a = 1.2x10^-6
v = ?

Using I = nAve, how do you work out v?