CFOT - Certified Fiber Optic Technician Fiber Optic Testing Questions and Answers

Question 1

A technician performing an insertion loss test on a newly installed fiber link obtains a measurement that is significantly higher than the calculated loss budget.
Which of the following is the MOST appropriate first step to troubleshoot the issue?

Accepted Answer

Inspect and, if necessary, clean the end-faces of the test cords and the link's connectors.

Answer

Immediately replace all connectors on the link.

Answer

Use an OTDR to find the exact location of the high-loss event.

Answer

Recalculate the loss budget with more generous loss allowances per component.

Question 2

When using an Optical Time Domain Reflectometer (OTDR) to test a long fiber optic cable, the technician notices a reflective event on the trace that has no associated loss and appears at an exact multiple of the distance to a highly reflective preceding connector. What is this phenomenon called?

Accepted Answer

A ghost

Answer

A gainer

Answer

A dead zone event

Answer

A non-reflective break

Question 3

A technician needs a simple, low-cost tool to quickly verify continuity and trace a specific fiber path within a bundle of patch cords at a cross-connect. The tool should also be able to identify breaks or sharp bends close to a connector. Which piece of test equipment is best suited for this task?

Accepted Answer

Visual Fault Locator (VFL)

Answer

Optical Loss Test Set (OLTS)

Answer

Optical Time Domain Reflectometer (OTDR)

Answer

Fiber Inspection Probe

Question 4

To ensure consistent and repeatable loss measurements on high-speed multimode fiber links (e.g., OM3, OM4), industry standards such as TIA-526-14-B specify a controlled launch condition. What is this standardized method of controlling the distribution of light power across the fiber core called?

Accepted Answer

Encircled Flux (EF)

Answer

Modal Dispersion Limit

Answer

Numerical Aperture Confinement

Answer

Core Alignment Referencing

Question 5

When performing an insertion loss test with a light source and power meter (LSPM), which reference method is generally considered the most accurate because it includes the loss of the connections at both ends of the link under test?

Accepted Answer

The one-cord reference

Answer

The three-cord reference

Answer

The two-cord reference

Answer

The no-cord reference

Question 6

An Optical Loss Test Set (OLTS) is comprised of which two fundamental pieces of equipment?

Accepted Answer

A light source and an optical power meter

Answer

An OTDR and a launch cable

Answer

A visual fault locator and a fiber microscope

Answer

A fusion splicer and a cleaver