Why is copper preferred in the construction of large knife switches?

Copper is often preferred in the construction of large knife switches primarily due to its excellent conductivity and durability. One of its standout properties is its "skinning" effect, which refers to the way electrical current tends to flow through the outer layer of the conductor. This characteristic enhances the efficiency of the switch, as it allows for lower resistance and better performance when handling electrical loads.

Moreover, copper's conductivity is much higher than that of many other metals, which means it can carry more current with less energy loss. This is crucial in applications such as large knife switches, where high current ratings are common. Additionally, copper has advantageous mechanical properties that contribute to the durability and reliability of the switch over time.

In contrast, other options may not hold the same level of importance in this application. While copper is not particularly lightweight, it is still contextually significant due to its strength and reliability. Cost-effectiveness is relative, as copper can be more expensive than some alternatives but is often considered a worthwhile investment due to its longevity and performance. Lastly, while corrosion resistance is important, copper can indeed tarnish when exposed to certain conditions, which is not as critical a property in this specific context as its conductivity.