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 {{}}

Mean drift velocity of electron in a copper wire having cross-sectiona

1.	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 s-1
B.	0.1 mm s-1
C.	0.5 mm s-1
D.	0.25 mm s-1
Answer» B. 0.1 mm s-1