Which combination correctly lists the parts of an underground cable?

• A. Jacket, metallic shield, polyethylene, stranded conductors, insulation
• B. Jacket, metallic shield, insulation
• C. Jacket, polyethylene, insulation
• D. Metallic shield, insulation

Answer: (A)

Understanding how underground cables are built helps you see why this sequence is correct. From outside to inside, the cable starts with a jacket that protects the inner components from moisture, chemicals, and mechanical damage. Inside that jacket is a metallic shield that provides a return path for fault currents and helps limit electromagnetic interference. Next is a polyethylene layer that serves as the dielectric between the shield and the current-carrying conductors. At the center are the stranded conductors themselves, and surrounding those conductors is the insulation that isolates and protects each conductor’s ability to carry current. This combination—jacket, metallic shield, polyethylene, stranded conductors, insulation—matches the typical construction of an underground cable. If any of these parts were missing or misplaced, protection, shielding, or proper electrical insulation would be compromised.