engineering recuitment AAI ATC Junior Executive 2025 Mock Test Series Physics Current, Resistance and Electricity Drift of Electrons and the Origin of Resistivity
A copper wire of 10-2 cm2 has 1029 electrons per m3 of the wire. If the current through the wire is 20 A, the drift velocity is-
1
1.25 × 10-3 m/s
2
1.25 × 10-4 m/s
3
125 × 10-3 m/s
4
1.25 × 10-6 m/s