DCI Fiber Optic Installation 4

Question 1

What is 'return loss' (RL) in a fiber optic connector, and why does it matter?

Accepted Answer

The amount of light reflected back toward the source, measured in dB

Answer

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.

Question 2

What color is the jacket of an APC (angled physical contact) fiber optic connector by standard convention?

Accepted Answer

Green

Answer

APC connectors are identified by a green color-coded body or boot, distinguishing them from UPC connectors which are typically blue or beige.

Question 3

An OTDR is set with a pulse width of 100 ns. Approximately how long is the resulting dead zone?

Accepted Answer

10 meters

Answer

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).

Question 4

Which method is used to join fiber optic cables in an outside plant environment where a permanent, low-loss connection is required?

Accepted Answer

Fusion splice

Answer

Fusion splicing provides the lowest loss and most durable permanent joint for outside plant applications by welding the glass fibers together.

Question 5

What is the standard core diameter of a single-mode fiber (SMF) per ITU-T G.652?

Accepted Answer

9 µm

Answer

Standard single-mode fiber has a 9 µm core diameter, which supports only one propagation mode at 1310 nm and 1550 nm wavelengths.

(DCI) Data Cabling Installer Practice Test

(DCI) Data Cabling Installer Practice Test

DCI Fiber Optic Installation 4