# If current in a current carrying wire is 1.5A, number of free electrons per unit volume is 8 x1028m3 and area of cross section is 5 mm2 . Drift velocity of electrons will be

a) 0.02 mm/s

b) 2 mm/s

c) 0.2 mm/s

d) None of these

i = e n A Vd (relation between i and Vd)

$V_{d}=\frac{1}{enA}= \frac{1.5}{1.6 \times 10^{-19}\times 5 \times10^{-6} \times 8 \times 10^{28}}=0.02$