Cables that transfer data using a single light path, with a core size of 8-105 microns?

• A. Multi-mode Fiber
• B. Coaxial
• C. Single-mode Fiber
• D. UTP

Answer: (C)

Single-mode fiber is built to carry light along a single propagation path. Its core is very small, about 8 to 10 microns, which confines light to one mode and minimizes modal dispersion. This allows signals to travel longer distances with higher bandwidth, making it ideal for long-haul and high-speed networks. In contrast, multi-mode fiber has a larger core (around 50 microns), supporting many light paths and introducing modal dispersion that limits distance and speed. Coaxial and UTP are copper-based cables, not optical fibers, so they don’t use a light path to transfer data. The description of data moving along a single light path with a small core aligns with single-mode fiber.