Answer
We can rank the three rods according to the drift speed:
$1 = 2 \gt 3$
Work Step by Step
In part (b), we ranked the rods according to the current density as follows:
$1 = 2 \gt 3$
We can write a general expression for the drift speed:
$v_d = \frac{J}{ne}$
$J$ is the current density
$ne$ is the carrier charge density
Note that the carrier charge density is an intrinsic characteristic of copper so it has the same value for all three rods.
Therefore, the ranking for the drift speed is the same as part (b).
We can rank the three rods according to the drift speed:
$1 = 2 \gt 3$
