Find the drift velocity of electrons in a metal conductor having density of conduction electrons $9 × 10^{28} m^{-3}$ of cross sectional area $2× 10^{-7} m^2$ carrying 2 A current:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 0.7 mm/s
The driff velocity of electrons in a metal conductor ($v_d$)
$v_d=\frac{I}{nAe}$
where,
I, Current = 2 A
n, Number density of conduction $e=9×10^{28}m^{-3}$
A, cross-sectional area = $2×10^{-7}m^2$
On substituting the values,
$v_d=\frac{2}{9×10^{28}×2×10^{-7}×1.6}$
$=0.000694m/s$
$≃0.7m/s$