NCTI Exam Fiber II Exam Questions and
Answers with Verified Solutions | Latest
Updated 2026
Why was the zero-dispersion point To take advantage of the low intrinsic
in absorption
single-mode fiber moved to 1,550 and lower attenuation at 1,550 nm in
nm? single-mode
fiber.
What type of single-mode fiber is The ITU-T G.657 bend-insensitive fiber
intended for fiber-to-the-home (BIF).
(FTTH) installations?
What are the primary causes of Material absorption and Rayleigh
intrinsic loss in single-mode fiber? scattering.
The phenomenon, total internal The difference in refractive indexes,
reflection, is what enables an between
optical cladding and core, causes light to be
fiber to guide light. What reflected off
characteristic of optical fiber the cladding and back into the core along
causes the
total internal reflection? optical fiber.
Where would you expect Fresnel At connections and mechanical splices
reflections to occur in a fiber-optic where the
network? signal source is entering or exiting the
cable.
, Chromatic dispersion is a Material and waveguide dispersion.
combination of which two
dispersions?
What is one advantage and one The larger the MFD, the easier it is to
disadvantage of single-mode fiber splice and
with a large mode field diameter connectorize the fiber, although it becomes
(MFD)? more
sensitive to bending losses.
What is the current standardized It is 125 µm, with an accuracy of ±1 µm.
outside diameter (OD) of the
cladding of single-mode fiber?
What do diameter differences Gain in one direction and high loss in the
between spliced fibers look like on opposite
an optical time domain direction.
reflectometer
(OTDR)?
Besides protection, what else must Function over a wide temperature range;
the coating on an optical fiber do? be
compatible with cable gels; adhere to the
glass
cladding over the lifetime of the cable; and
be
mechanically strippable for splicing
operations.
How do technicians know the They have read the project's specification
specific type of single-mode fiber records.
used in a particular project?
Answers with Verified Solutions | Latest
Updated 2026
Why was the zero-dispersion point To take advantage of the low intrinsic
in absorption
single-mode fiber moved to 1,550 and lower attenuation at 1,550 nm in
nm? single-mode
fiber.
What type of single-mode fiber is The ITU-T G.657 bend-insensitive fiber
intended for fiber-to-the-home (BIF).
(FTTH) installations?
What are the primary causes of Material absorption and Rayleigh
intrinsic loss in single-mode fiber? scattering.
The phenomenon, total internal The difference in refractive indexes,
reflection, is what enables an between
optical cladding and core, causes light to be
fiber to guide light. What reflected off
characteristic of optical fiber the cladding and back into the core along
causes the
total internal reflection? optical fiber.
Where would you expect Fresnel At connections and mechanical splices
reflections to occur in a fiber-optic where the
network? signal source is entering or exiting the
cable.
, Chromatic dispersion is a Material and waveguide dispersion.
combination of which two
dispersions?
What is one advantage and one The larger the MFD, the easier it is to
disadvantage of single-mode fiber splice and
with a large mode field diameter connectorize the fiber, although it becomes
(MFD)? more
sensitive to bending losses.
What is the current standardized It is 125 µm, with an accuracy of ±1 µm.
outside diameter (OD) of the
cladding of single-mode fiber?
What do diameter differences Gain in one direction and high loss in the
between spliced fibers look like on opposite
an optical time domain direction.
reflectometer
(OTDR)?
Besides protection, what else must Function over a wide temperature range;
the coating on an optical fiber do? be
compatible with cable gels; adhere to the
glass
cladding over the lifetime of the cable; and
be
mechanically strippable for splicing
operations.
How do technicians know the They have read the project's specification
specific type of single-mode fiber records.
used in a particular project?
