Current is flowing with a current density J=480 A cm -2 in a copper wire. Assuming that each copper atom contributes one free electron and given that Avogadro number =6.0 × 1023 atoms / mole Density of copper =9.0 g / cm 3 Atomic weight of copper =64 g / mole Electronic charge =1.6 × 10-19 coulomb The drift velocity of electrons is

Question

Current is flowing with a current density J=480 A cm -2 in a copper wire. Assuming that each copper atom contributes one free electron and given that Avogadro number =6.0 × 1023 atoms / mole Density of copper =9.0 g / cm 3 Atomic weight of copper =64 g / mole Electronic charge =1.6 × 10-19 coulomb The drift velocity of electrons is (A) 1 mm / s (B) 2 mm / s (C) 0.5 mm / s (D) 0.36 mm / s

Tardigrade Admin · Accepted Answer

Drift velocity, vd=( text Current density /n e) n= number of electrons per unit volume or n=(( text Avogadro number ) × text Density / text Atomic weight of copper ) or n=(6 × 1025 × 9/64) vd=480 × (64/6 × 1023 × 9 × 1.6 × 10-19) =(480 × 64/6 × 9 × 1.6 × 10000) cm / s or vd=(32/900) cm / s =(32 × 10/900) mm / s =0.36 mm / s

$1 mm / s$

$2 mm / s$

$0.5 mm / s$

$0.36 mm / s$

1mm/s

2mm/s

0.5mm/s

0.36mm/s

Drift velocity, vd​=ne Current density ​ n= number of electrons per unit volume or n= Atomic weight of copper ( Avogadro number )× Density ​ or n=646×1025×9​ vd​=480×6×1023×9×1.6×10−1964​ =6×9×1.6×10000480×64​cm/s or vd​=90032​cm/s=90032×10​mm/s=0.36mm/s

$1 mm / s$

$2 mm / s$

$0.5 mm / s$

$0.36 mm / s$