A wire, 1.2mm in diameter and 32 cm long, carries a current of 648 ma.

1.	A wire, 1.2mm in diameter and 32 cm long, carries a current of 648 ma. The density of free electrons in the wire is 5.90 × 1028m-3.The drift velocity of electrons in the wire is:
Answer» Volume of WIRE = $\pi$ * ( $d^{2}$ / 4) * L = 3.14 * ((0.00120.0012)/4) 0.032 = 3.6 * $<klux>10</klux>^{-8}$ *Current = number of ELECTRONS e * Drift velocity** Drift velocity = Current / (number of electrons * e) = 0.648 / (3.6 * $10^{-8}$ * 5.90 * $10^{28}$ * 1.6 * 10 * $10^{-19}$ ) = 0.00019067796 m/sec