Fiber Optic Installation Flashcards
7 cards from real DCI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fiber Optic Installation flashcards as text
What is 'return loss' (RL) in a fiber optic connector, and why does it matter?
Answer: The amount of light reflected back toward the source, measured in dB
Return loss quantifies the optical power reflected back toward the source; high return loss (e.g., >55 dB for UPC) means less reflection, which is critical for laser stability.
What color is the jacket of an APC (angled physical contact) fiber optic connector by standard convention?
Answer: Green
APC connectors are identified by a green color-coded body or boot, distinguishing them from UPC connectors which are typically blue or beige.
An OTDR is set with a pulse width of 100 ns. Approximately how long is the resulting dead zone?
Answer: 10 meters
A 100 ns pulse corresponds to approximately 10 meters of dead zone, since light travels about 0.2 m/ns in fiber (speed ÷ 2 for round trip).
Which method is used to join fiber optic cables in an outside plant environment where a permanent, low-loss connection is required?
Answer: Fusion splice
Fusion splicing provides the lowest loss and most durable permanent joint for outside plant applications by welding the glass fibers together.
What is the standard core diameter of a single-mode fiber (SMF) per ITU-T G.652?
Answer: 9 µm
Standard single-mode fiber has a 9 µm core diameter, which supports only one propagation mode at 1310 nm and 1550 nm wavelengths.
When installing fiber optic cable in an aerial application, what is the primary purpose of the messenger wire?
Answer: To provide mechanical support and carry the cable's weight
The messenger wire (steel strand) carries the mechanical load of the cable span, relieving tension from the fiber itself.
What is the recommended power level range for testing a fiber link with an optical power meter when using a 1310 nm source?
Answer: Within the calculated link loss budget ±3 dB
The measured power should fall within the calculated link loss budget tolerance; exceeding the budget indicates a fault, while being far under may mean fiber type mismatch.