Current is flowing with a current density j=480Acm−2 in a copper wire.
Assuming that each copper atom contributes one free electron and given that Avogadro number =6.0×1023atommol−1
Density of copper =9.0gcm−2
Electronic charge =1.6×10−19C
Atomic weight of copper =64gmol−1
The drift velocity of electrons is
Drift velocity is given by vd=nqAI where I is current, n the number of electrons, A the area, q the charge. Given AI=cm2480Aandq=1.6×10−19C n=646×1023×9 ∴vd=480×6×1023×9×1.6×10−1964 ⇒vd=6×9×1.6×10000480×64cms−19 ⇒vd=90032cms−1 =90032×10cms−1 =0.36mms−1 ⇒vd=0.36mms−1
Electromagnetic Induction is a current produced by the voltage production due to a changing magnetic field. This happens in one of the two conditions:-
When we place the conductor in a changing magnetic field.
When the conductor constantly moves in a stationary field.