Primary use of solid vs stranded conductors?

• A. Stranded conductors for long fixed runs; solid conductors for flexible patch cords.
• B. Solid conductors for long, fixed runs (horizontal cabling); stranded conductors for flexible applications (patch cords and equipment cords).
• C. Solid conductors for patch cords; stranded conductors for long runs.
• D. Stranded conductors for power; solid conductors for signaling.

Answer: (B)

The key idea is that the mechanical nature of the conductor dictates where it works best: solid conductors are stiff and stay put, while stranded conductors are flexible and can handle movement. Solid conductors are a single, solid strand, so they’re easier to run through walls and conduit and terminate cleanly in fixed installations. Because they don’t bend easily, they’re well suited to long, fixed horizontal runs from the telecommunications room to work-area outlets. Stranded conductors, made up of many fine wires twisted together, bend and flex much more readily, which makes them ideal for connections that are frequently moved or unplugged—like patch cords and equipment cords. They resist fatigue from repeated bending and maintain reliability in flexible applications. So the standard practice is to use solid conductors for long, fixed horizontal runs, and stranded conductors for flexible uses such as patch cords and equipment cords.