Question

The drift speed in a copper wire is 7.89 ✕ 10−5 m/s for a typical electron current. Calculate the magnitude of the electric field E inside the copper wire. The mobility of mobile electrons in copper is 4.5 ✕ 10−3 (m/s)/(N/C). (Note that though the electric field in the wire is very small, it is adequate to push a sizable electron current through the copper wire.)

Answer 1

Answer:

$E$  = 0.0175 N/C

Explanation:

$v$ = drift speed in a copper wire = 7.89 x 10⁻⁵ m/s

μ = mobility of mobile electrons in copper wire = 4.5 x 10⁻³ (m/s)/(N/C)

$E$ = magnitude of electric field in the wire

Drift speed is given as

$v$ = μ $E$

Inserting the values

7.89 x 10⁻⁵ = (4.5 x 10⁻³) $E$

$E$  = 0.0175 N/C