Final answer:
The concentric wire with the greater circumference will have a longer length and assuming all else is equal, a greater resistance. This principle relates to the question about aluminum and copper wires of the same length and resistance; the aluminum wire must have a larger diameter due to its higher resistivity. Option A is correct.
Step-by-step explanation:
When two circular arcs of wires are concentric and are made from the same material, the one with the greater circumference will be the larger, which correlates to a frequency asked schoolwork question regarding electrical properties of wires.
If we are talking about two wires made from the same material, we can use the formulas for resistance which show that resistance is directly proportional to the length of the wire. Thus, the wire that forms the larger circular arc, which is the one with the greater circumference, will inherently have a longer length and, assuming all other factors are equal, a greater resistance.
For example, regarding the other parts of the example question involving the comparison of aluminum and copper wires of the same length, if they have the same resistance, the one with the larger diameter must be the aluminum wire because aluminum has a higher resistivity than copper, which would require a larger cross-sectional area to compensate for this property to achieve the same resistance.