The relaxation time for collision of electrons with ions in a conducting wire is 1.6 x 10⁻¹² s. The mobility of electrons is:
a) 1.6 x 10⁻¹² m²/Vs
b) 6.25 x 10⁻¹² m²/Vs
c) 625 x 10⁻¹² m²/Vs
d) 0.625 x 10⁻¹² m²/Vs