CFOT Cheat Sheet 2026

The 30 highest-yield CFOT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. According to IEEE 802.3, what is the minimum modal bandwidth required for OM3 multimode fiber at 850 nm? → 2000 MHz·km
2. What type of inspection tool is best suited for examining connectors already installed inside adapters or bulkheads? → Video inspection probe
3. What does a reel-type cassette cleaner use to clean fiber optic connector end-faces? → Pre-moistened and dry cleaning fabric that advances to a fresh section each use
4. Which of the following is a primary cause of intrinsic attenuation in an optical fiber, resulting from microscopic variations in the density of the glass? → Rayleigh scattering
5. What is an optical attenuator used for in a fiber optic link? → Reduce optical power to prevent receiver saturation
6. A fiber optic patch panel in a telecommunications room primarily serves what function? → Provide a flexible cross-connect point between backbone and horizontal cabling
7. The National Electrical Code (NEC) Article 770 specifically regulates which aspect of fiber optics? → Installation of optical fiber cables in buildings
8. Which regulatory body sets safety standards for fiber optic installations in the United States? → Occupational Safety and Health Administration (OSHA)
9. Per IEC 61300-3-35, which inspection zone on a connector end-face is most critical for optical signal quality? → Zone A (core region)
10. In a fiber optic distribution frame (ODF), what is the purpose of the splice tray? → Organize and protect fusion or mechanical splices between pigtails and incoming fiber
11. What is the primary function of an optical amplifier (EDFA) in a fiber optic network? → Amplify optical signals directly without converting to electrical signals
12. In a fiber optic cable, what is the primary function of the aramid yarn (e.g., Kevlar®) component? → To absorb pulling forces during installation and provide tensile strength.
13. According to TIA-568, what is the maximum channel insertion loss allowed for a single multimode fiber connection? → 0.75 dB
14. A technician notices a significant amount of signal loss (attenuation) only when a patch cord is bent at a sharp angle. This type of loss is known as: → Macrobending loss
15. What is the purpose of a wavelength division multiplexer (WDM) in a fiber optic system? → Combine or separate multiple wavelengths onto a single fiber
16. Which type of optical coupler/splitter divides one optical input into two or more outputs while maintaining a defined split ratio? → Fused biconical taper (FBT) or planar lightwave circuit (PLC) splitter
17. What does 'reach' refer to in the context of fiber optic transceiver specifications? → The maximum supported transmission distance for the transceiver at a given data rate
18. During a cable pull, a breakaway swivel is used as a crucial piece of hardware. What is the primary function of this device? → To disconnect the pull rope from the cable if the pulling tension exceeds a preset limit.
19. What is the function of a lockout/tagout (LOTO) procedure in fiber optic safety? → To prevent accidental exposure to live fibers
20. Why is it crucial to verify that a fiber optic cable is not live before handling it? → To prevent eye injury from laser exposure
21. Under NEC Article 770, which cable jacket rating is required for fiber optic cables installed in plenums? → OFNP (Optical Fiber Nonconductive Plenum)
22. What should a technician do if they suspect a chemical spill involving fiber optic materials? → Report it immediately and follow hazardous material protocols
23. What is the difference between a simplex and a duplex fiber optic cable assembly? → Simplex has one fiber; duplex has two fibers in one jacket for separate TX and RX paths
24. Which ANSI/TIA standard defines the color coding and labeling requirements for fiber optic infrastructure? → TIA-606
25. Which cleaning tool is designed specifically to clean the ferrule end-face of a connector installed inside an adapter? → Stick cleaner (push-to-clean device)
26. What is the primary advantage of using a heat-cured epoxy for terminating fiber optic connectors in a factory setting? → Highest reliability and lowest loss due to a strong fiber-to-ferrule bond.
27. For a fiber optic communication link to function correctly, which of the following statements about the Power Budget and Loss Budget must be true? → The Power Budget must be greater than the calculated Loss Budget.
28. What is the role of a fiber optic fusion splicer in ensuring safety during installations? → It provides a safe way to join fiber cables without open flames
29. Which component of a fiber optic connector is primarily responsible for aligning the fiber core with another fiber? → The ferrule
30. Why must technicians never look directly into the end of an active fiber optic cable or connector? → Infrared laser light can cause permanent eye damage with no visible warning