Which shielding method uses a solid metal tube to protect cables from interference?

• A. Stranded Conductors
• B. Pulse Code Modulation
• C. Solid Metallic Conduit
• D. SNR

Answer: (C)

Shielding with a metallic barrier around cables is about blocking external interference with a conductive enclosure. A solid metal tube, known as solid metallic conduit, surrounds the cables with a continuous metal barrier, providing EMI shielding as well as physical protection. Grounding the conduit helps channel unwanted noise away from the conductors, further reducing interference. The other options don’t fit shielding: stranded conductors describe how the wire is built, not shielding; Pulse Code Modulation is an encoding method; SNR is a performance metric for signal quality.