Copper-clad steel and copper alloys have what drawback compared to pure copper?

Copper-clad steel and copper alloys have what drawback compared to pure copper?

• A. inferior current-carrying ability
• B. higher cost
• C. better flexibility
• D. lower strength

Answer: (A)

The key point is conductivity. Pure copper has the lowest resistivity among common conductive metals, so for a given cross-section it carries more current with less heating and voltage drop than other materials. Copper-clad steel and copper alloys give up some of that conductivity to gain strength or other properties. In copper-clad steel, most of the cross-section is steel, which conducts much worse than copper. The thin copper layer helps a little, but the overall path that electrons take still has higher resistance, so the current-carrying capability is reduced compared with solid copper of the same size. With copper alloys, alloying elements scatter electrons and disrupt the copper lattice, which raises resistivity and lowers conductivity relative to pure copper. So, the common drawback is inferior current-carrying ability.

The key point is conductivity. Pure copper has the lowest resistivity among common conductive metals, so for a given cross-section it carries more current with less heating and voltage drop than other materials. Copper-clad steel and copper alloys give up some of that conductivity to gain strength or other properties. In copper-clad steel, most of the cross-section is steel, which conducts much worse than copper. The thin copper layer helps a little, but the overall path that electrons take still has higher resistance, so the current-carrying capability is reduced compared with solid copper of the same size. With copper alloys, alloying elements scatter electrons and disrupt the copper lattice, which raises resistivity and lowers conductivity relative to pure copper. So, the common drawback is inferior current-carrying ability.