railway RRB Technician Grade 1 Mock Test 2024 Physics Current, Resistance and Electricity Drift of Electrons and the Origin of Resistivity
Assume that each atom of copper contributes one free electron. If the current flowing through a copper wire of 1 mm diameter is 1.1 A, the drift velocity of electrons will be (density of Cu = 9 gm/cm3, At. wt. of Cu = 63)
1
0.3 mm/s
2
0.5 mm/s
3
0.1 mm/s
4
0.2 mm/s