?

Electricity and Magnetism

Free Version

Upgrade subject to access all content

Moderate

Charge Flow in a Copper Wire

Free
EANDM-VILIYM

A copper wire of radius $r = 2\:mm$ and length $L=2\:m$ has a current of $ I =6.2 \:A$ flowing in it.

For what length of time in hours must the current flow before (on average) all of the original electrons in the wire will have been replaced? [The electron density of copper is ${n}_{Cu} = 8.46 \times {10}^{28} {m}^{-3}$].

A

$1.85 \times {10}^{-12} hr$

B

$3.7 \times {10}^{-12} \:hr$

C

$0.27 \:hr$

D

$15.2 \:hr$

E

$27.1 \:hr$