Copper has 8.5 X 1028 free electrons per cubic meter. A74.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.65 A of current.
a) How much time does it take for an electron to travel the length of the wire?
b) Repeat part (a) for measure copper wire (diameter 4.12 mm) of the same length that carries the same current.
c) Normally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?