Mean drift velocity of electron in a copper wire having cross-sectional area 5.0 × 10-6 m2 carrying current of 1 A and having number density 8.5 × 10 28 m3 is
A. 0.015 mm *-1
B. 0.1 mm *-1
C. 0.5 mm *-1
D. 0.25 mm *-1
