Which of the following materials is typically preferred for electrical conductors due to its high conductivity and resistance to corrosion?

The correct answer is 4) Copper.

Concept:

• High Conductivity: Copper is well-known for its excellent electrical conductivity, second only to silver among pure metals. This allows for efficient transfer of electrical current with minimal energy loss.  
   

   
• Resistance to Corrosion: Copper has good resistance to corrosion in various environments. It forms a protective layer of copper oxide or copper carbonate (patina) when exposed to the atmosphere, which inhibits further corrosion.  
   

   
• Cost-Effective: While gold also has high conductivity and excellent corrosion resistance, it is significantly more expensive than copper, making copper the preferred choice for most electrical conductor applications.
   

Option Analysis:

• Manganin: Manganin is an alloy known for its stable electrical resistance over a range of temperatures, making it suitable for precision resistors, not general conductors.  
   
• Steel: Steel has relatively low electrical conductivity compared to copper and is prone to corrosion (rusting) unless specially treated or alloyed.  
   
• Gold: While having excellent conductivity and corrosion resistance, its high cost limits its use to specialized applications where these factors outweigh the expense, such as in electronics for critical contacts.