A copper wire of cross-sectional area A = 1 mm² carries current I = 1.6 A. Find the drift velocity. (Free electron density n = 8.5 × 10²⁸ /m³, e = 1.6 × 10⁻¹⁹ C)

vd = (I)/(nAe) = (1.6)/(8.5×10²⁸ × 10⁻⁶ × 1.6×10⁻¹⁹) vd = (1.6)/(1.36×10⁴) ≈ 1.18 × 10⁻⁴ m/s

JEE physics

A copper wire of cross-sectional area A = 1 mm² carries current I = 1.6 A — JEE Physics

SPSuresh Pillai · 9 Asked 1mo ago 120 views 1 answer

A copper wire of cross-sectional area $A = 1\ mm^2$ carries current $I = 1.6$ A. Find the drift velocity. (Free electron density $n = 8.5 \times 10^{28}$ /m³, $e = 1.6 \times 10^{-19}$ C)

1 Answer

KSKaran Singh ✓ Accepted · 1mo ago ▲ 14

$$v_d = \frac{I}{nAe} = \frac{1.6}{8.5\times10^{28} \times 10^{-6} \times 1.6\times10^{-19}}$$

$$v_d = \frac{1.6}{1.36\times10^{4}} \approx 1.18 \times 10^{-4} m/s$$

Discussion (3)

Brilliant explanation, the substitution step is what I kept missing.

Tushar Saxena · 1mo ago

Underrated solution. The way you set it up makes it almost obvious.

AnanyaPatel44 · 30d ago

Can someone explain why we ignore the other root here?

Meera Pillai · 28d ago

← Back to all questions