What will be drift velocity vd of the free electron in a copper wire whose cross sectional area is A = 1.00 mm2 when the wire carries a current of 1.0 A. Assume that each copper atom contributes 1 electron to the electron gas. (Given density of copper = 8.94 × 103 kg/m3, atomic mass of copper = 63.5 u, 1 u = 1.66 × 10-27 kg)
1
7.4 × 10-5 m/s
2
7.4 × 10-2 m/s
3
7.4 × 10-7 m/s
4
7.4 m/s