10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The FEEC exam has 25 questions and runs 2 hours.
These 10 free FEEC questions are organized by exam domain, so you can see how each part of the Fiber Optics Evaluation & Endface Cleaning (FEEC) blueprint is tested. Reveal the answer and explanation under each question.
Controlled tests of a clean, aligned junction show more coupling loss from a 62.5/125 micrometer fiber into a 50/125 micrometer fiber than in the reverse direction. The fibers have the same numerical aperture. Which feature of the junction accounts for this difference?
Correct answer: A - The smaller receiving core captures only part of the larger core's optical field.
Both the core and cladding of a conventional step-index glass fiber are transparent. What allows light launched within the fiber's acceptance cone to remain guided in the core?
Correct answer: D - The core has the higher refractive index, permitting total internal reflection.
At the same wavelength and incident power, terminations X and Y each have an insertion loss of 0.3 dB. Their optical return losses are 32 dB and 48 dB, respectively. Which statement correctly describes the reflected light?
Correct answer: C - Termination Y returns less light toward the source.
A D38999 plug terminus passes video inspection after cleaning. Its endface remains clean while protected, but fresh particles appear after it is mated to and separated from the receptacle. Link loss also increases after mating. What should be addressed before another connection is made?
Correct answer: B - Inspect and clean the corresponding receptacle interface before remating the cleaned plug.
A disconnected fiber interface appears dark, so a technician prepares to inspect it with a 200x direct-view microscope. The circuit uses a 1310 nm transmitter, and the far-end transmitter's status has not been established. What takes precedence over the inspection?
Correct answer: C - Isolate the source and verify absence of optical power with a suitable power meter.
Fresh dry-cleaning media remove loose debris from an accessible single-ferrule connector, but inspection still shows an oily film. The maintenance procedure permits a specified fiber-optic solvent and lint-free wipes. Choose the appropriate cleaning sequence.
Correct answer: A - Use the approved solvent with a wipe, finish on a clean dry area, then reinspect.
A technician is ready to mate a replacement cable. Immediately after removing the protective caps, both mating endfaces pass the prescribed inspection. Neither has touched another surface, and no additional cleaning is required by the maintenance procedure. The next step should be to:
Correct answer: A - Proceed with mating using the prescribed coupling method.
An optical loss test set reports a 0.6 dB gain through a passive aircraft harness. The source is stable. The test log shows that a contaminated test-cord endface was cleaned after the zero reference was stored. How should this result be handled?
Correct answer: D - Establish a clean reference and repeat the harness loss measurement.
During an 850 nm link-loss test, the verified reference power is -8.2 dBm and the power received through the cable is -11.6 dBm. The task card limits cable loss to 2.5 dB. Although the connected receiver can operate down to -15.0 dBm, which result belongs on the cable acceptance record?
Correct answer: C - 3.4 dB loss; fails the cable-loss requirement.
An isolated harness with ARINC 600 interfaces has two required paths: P1 cavity 3 to P2 cavity 7, and P1 cavity 4 to P2 cavity 8. A visual fault locator instead traces 3 to 8 and 4 to 7. Both observed paths pass insertion-loss testing. Which defect does the tracing reveal?
Correct answer: B - A transposition of the two fiber paths.
The full bank has 1,020 more FEEC questions with explanations.
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