Which type of fiber cable carries data via multiple light paths and typically has a core diameter of 50–100 microns?

• A. Multi-mode Fiber
• B. Single-mode Fiber
• C. Fiber (Generic)
• D. Plastic Fiber

Answer: (A)

Understanding fiber optic cable types and how core size affects light propagation. Data traveling via multiple light paths describes modal transmission, which happens when the fiber has a relatively large core that can support several propagation modes. Core diameters around 50 to 100 microns are characteristic of multimode fiber (such as 50/125 or 62.5/125). In multimode fiber, light can take many paths through the core, which makes it more susceptible to modal dispersion but is adequate for shorter-distance links and commonly uses cheaper light sources like LEDs. Single-mode fiber, by contrast, has a much smaller core (about 8–10 microns) designed to carry light along a single path, suitable for long-distance, high-bandwidth links, and does not match the 50–100 micron core size. Plastic fiber is a different material and isn’t described by this core-size range in standard contexts. Therefore, the description fits multimode fiber best.