Passage II

Resistivity is the tendency of a material to oppose the flow of an electric current, whereas conductivity is the ability of a material to carry an electric current. Table 1 lists, for each of 12 metals at the same temperature, the density (in grams per cubic centimeter, g/cm3), resistivity (in ohm meters, Ω∙m), and conductivity (in siemens per meter, S/m). Figure 1 shows, for 3 of these metals, how resistivity varies with temperature (in kelvins, K).

12. When choosing a suitable metal for use in overhead electrical cables, engineers prefer a metal for which the expression (density) × (resistivity) has as small a value as possible. Based on Table 1, which of the following metals would be most suitable for use in an overhead cable?

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

Exclude by calculation. After calculation, the density×resistivity value of aluminum is the smallest, so aluminum will be selected