Question

What will be drift velocity $v_d$ 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 = 8.94x103 kg/m3, atomic mass of copper = 63.5 u, 1 u = 1.66x10-27 kg)

• A. 7.4×10-5m/s
• B. 7.4×10-2 m/s
• C. 7.4×10-7 m/s
• D. 7.4 m/s

Answer 1

Answer: (A)

7.4×10-5m/s

Answer 2

The correct option is (A)