A copper wire of 3 m m 2 cross-sectional area carries a current 5 A . The magnitude of the drift velocity for the electrons in the wire is (Assume each copper atom contributes one free electron and density of copper = 8920 kg m - 3 , M Cu = 63 .5 kg mol - 1 )

Step-by-step solution

Given, A = 3 × 10 - 6 m 2 , I = 5 A , M Cu = 63 .5 kg mol - 1 ρ C u = 8920 kg m - 3 Electron density = 6.023 × 10 23 × 8920 63.5 = 8.46 × 10 25 m - 3 ∴ Drift velocity, v d = I e n A = 5 1.6 × 10 - 19 × 8.46 × 10 25 × 3 × 10 - 6 = 5 40.608 = 0 .12 m s - 1