Question

The resistivity of gold is 2.44 × 10-8 ohm · m at a temperature of20°C. A gold wire, 0.5 mm in diameter and 44 cm long, carries acurrent of 380 ma. The number of electrons per second passingagiven cross section of the wire is closest to:

A) 6.3 × 10^15 B) 2.4 × 10^17 C) 1.2 × 10^22 D) 2.8 × 10^14 E) 2.4× 10^18