Wires A and B, made from the same metal, are connected in parallel across a cell of negligible internal resistance. Wire A has length LLL, diameter ddd, and the mean drift velocity of electrons in it is 0.64 mm s-1. Wire B has length 4L, diameter 3d3d3d, and mean drift velocity vvv. What is the mean drift velocity v v\,v of the electrons in wire B?
0.16 mm s−10.16\text{ mm s}^{-1}0.16 mm s−1
0.48 mm s−10.48\text{ mm s}^{-1}0.48 mm s−1
0.64 mm s−10.64\text{ mm s}^{-1}0.64 mm s−1
1.44 mm s−11.44\text{ mm s}^{-1}1.44 mm s−1
