NCTI Exam Fiber II
When preparing fiber-optic cable for connection to a patch panel, how much buffer tube and fiber slack should be provided?
Leave enough slack in the buffer tubes to allow the splice trays to reach the splicing equipment and enough fiber slack to store on individual trays for later additions, moves, and changes.
Which type of fiber-optic cable provides the most stable transport characteristics and additional protection from stresses caused by macrobends and microbends?
Loose-tube cable.
What step should be performed at the beginning of every fusion splicing operation?
Make a number of test splices to set up the fusion splicer and to verify the instrument's settings and calibration for both the environment and the type of fiber to be spliced.
What are the primary causes of intrinsic loss in single-mode fiber?
Material absorption and Rayleigh scattering.
Chromatic dispersion is a combination of which two dispersions?
Material and waveguide dispersion.
How are optical splitters used in the forward path?
Passive branching devices that divide an optical signal across multiple output fibers.
Which statement about pigtails used for optical fiber terminations is true?
Prior to splicing, pigtails should be labeled to correspond with the correct color code and patch panel designation.
In an optical network, what is reflectance?
Reflectance is the reflected light from a single Fresnel reflection event.
What is a consideration for the use of ribbon fiber?
Ribbon fiber requires different tools and equipment to perform splicing.
Since they provide the same functions, what is the primary difference between the fiber distribution hub (FDH) and fiber access terminal (FAT)?.
The FAT is typically easier to install and has lower fiber counts than the FDH.
What type of single-mode fiber is intended for fiber-to-the-home (FTTH) installations?
The ITU-T G.657 bend-insensitive fiber (BIF).
The quality and attenuation value of a mechanical splice of optical fibers is dependent on which tool during the preparation process?
The cleaving tool.
The phenomenon, total internal reflection, is what enables an optical fiber to guide light. What characteristic of optical fiber causes total internal reflection?
The difference in refractive indexes, between cladding and core, causes light to be reflected off the cladding and back into the core along the optical fiber.
If tight-buffered distribution fiber-optic cable is installed between the master splice panel in an optical entrance enclosure (OEE) and a rack-mounted fiber-optic distribution panel, where in the facility must the distribution panel be located?
The distribution panel can be located anywhere in the facility since the distribution cable complies with indoor code requirements for riser or plenum installations.
What are the two critical elements that align the optical fibers in a connection?
The ferrules and the mating adapter.
Which type of fusion splicer is ideal for fiber-to-the-x (FTTx) splicing?
The fixed V-groove splicer.
What is one advantage and one disadvantage of single-mode fiber with a large mode field diameter (MFD)?
The larger the MFD, the easier it is to splice and connectorize the fiber, although it becomes more sensitive to bending losses.
Which fusion splicer alignment method uses a camera to align the optical fibers before splicing?
The profile alignment system (PAS) method.
How do technicians know the specific type of single-mode fiber used in a particular project?
They have read the project's specification records.
Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm?
To take advantage of the low intrinsic absorption and lower attenuation at 1,550 nm in single-mode fiber.
What are some prerequisites before performing a fusion splice of optical fibers?
A controlled environment such as a splicing van, trailer, or tent and a stable work surface that is large enough to accommodate the fusion splicer, tools, and the splice closure.
What is required of mechanical splices used for acceptance testing?
A mechanical splice used for acceptance testing should be simple to use and reusable.
Where would you expect Fresnel reflections to occur in a fiber-optic network?
At connections and mechanical splices where the signal source is entering or exiting the cable.
Why are Velcro straps preferred over standard plastic tie wraps when bundling pigtails for storage in a splice panel?
Because Velcro straps are removable and can hold the pigtails together without placing undue strain on the optical fibers.
How should surface particulates usually be removed from optical connectors?
By using a compressed-air cleaner designed for optical connectors.
Besides protection, what else must the coating on an optical fiber do?
Function over a wide temperature range; be compatible with cable gels; adhere to the glass cladding over the lifetime of the cable; and be mechanically strippable for splicing operations.
Which optical splitter package is similar in appearance and size to a standard fusion splice protector?
Fused biconical taper (FBT).
What do diameter differences between spliced fibers look like on an optical time domain reflectometer (OTDR)?
Gain in one direction and high loss in the opposite direction.
When would a mid-entry splice in a fiber-optic network be used?
In a self-healing ring network that requires only two fibers to feed an optical fiber drop.
What is the current standardized outside diameter (OD) of the cladding of single-mode fiber?
It is 125 μm, with an accuracy of ±1 μm.