Four cylindrical conductors, A through D, are listed in the table below. All wires are at the same temperature.
Wire
Length (m)
Diameter (mm)
Material (relative resistivity)
A
1.0
1.0
copper (baseline)
B
1.0
2.0
aluminum (1.6 × copper)
C
2.0
1.0
copper (baseline)
D
1.0
1.0
nichrome (50 × copper)
(The parenthetical values indicate how many times larger the material’s resistivity is compared with that of copper.)
(a) Rank the four wires from greatest to least resistance. If any wires have equal resistance, state that explicitly.
(b) Select ONE pair of adjacent wires in your ranking and explain, without performing numerical calculations, the physical reasoning that justifies their order.