Answer:
Choice B. If the dimensions of the wires among the choices are the same, the copper one at room temperature would have the least electrical resistance.
Explanation:
Under room temperature, the electrical conductivity of copper is much better than that of steel.
Assume that the dimensions of the four wires are the same. Under the same temperature, the electrical resistance of the copper wire would be lower than that of the steel wire. Thus, [tex]B < A[/tex].
The electrical resistance of metal conductors tend to increase as temperature increases.
Therefore, the resistance of a copper wire at room temperature would be higher than the resistance of the same wire at a higher temperature. Thus, [tex]B < D[/tex].
Likewise, the resistance of the same steel wire would be higher at higher temperature. Thus, [tex]A < C[/tex].
Overall, [tex]B < A < C[/tex] and [tex]B < D[/tex]. Therefore, the copper wire at room temperature would have the least electric resistance among all four choices.
