The Diameter of a 12-Gauge Copper Wire Is 0

Multiple Choice

The diameter of a 12-gauge copper wire is 0.081 in.The maximum safe current it can carry (in order to prevent fire danger in building construction) is 20 A.At this current,what is the drift velocity of the electrons? The number of electron carriers in 1.0 cm³ of copper is 8.5 × 10²² and e = 1.60 × 10^-19 C.

A) 0.044 mm/s
B) 0.44 mm/s
C) 0.44 cm/s
D) 0.44 m/s
E) 4.4 cm/s