NCTI Exam Fiber II Questions And Answers
Why was the zero-dispersion point in single-mode fiber moved to
1,550 nm? -
correct answer ✅To take advantage of the low intrinsic absorption
and lower attenuation at 1,550 nm in single-mode fiber.
What type of single-mode fiber is intended for fiber-to-the-home
(FTTH) installations? -
correct answer ✅The ITU-T G.657 bend-insensitive fiber (BIF).
What are the primary causes of intrinsic loss in single-mode fiber? -
correct answer ✅Material absorption and Rayleigh scattering.
The phenomenon, total internal reflection, is what enables an
optical fiber to guide light. What characteristic of optical fiber
causes total internal reflection? -
correct answer ✅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.
Where would you expect Fresnel reflections to occur in a fiber-optic
network? -
correct answer ✅At connections and mechanical splices where the
signal source is entering or exiting the cable.
, NCTI Exam Fiber II Questions And Answers
Chromatic dispersion is a combination of which two dispersions? -
correct answer ✅Material and waveguide dispersion.
What is one advantage and one disadvantage of single-mode fiber
with a large mode field diameter (MFD)? -
correct answer ✅The larger the MFD, the easier it is to splice and
connectorize the fiber, although it becomes more sensitive to
bending losses.
What is the current standardized outside diameter (OD) of the
cladding of single-mode fiber? -
correct answer ✅It is 125 μm, with an accuracy of ±1 μm.
What do diameter differences between spliced fibers look like on
an optical time domain reflectometer (OTDR)? -
correct answer ✅Gain in one direction and high loss in the
opposite direction.
Besides protection, what else must the coating on an optical fiber
do? -
correct answer ✅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.
Why was the zero-dispersion point in single-mode fiber moved to
1,550 nm? -
correct answer ✅To take advantage of the low intrinsic absorption
and lower attenuation at 1,550 nm in single-mode fiber.
What type of single-mode fiber is intended for fiber-to-the-home
(FTTH) installations? -
correct answer ✅The ITU-T G.657 bend-insensitive fiber (BIF).
What are the primary causes of intrinsic loss in single-mode fiber? -
correct answer ✅Material absorption and Rayleigh scattering.
The phenomenon, total internal reflection, is what enables an
optical fiber to guide light. What characteristic of optical fiber
causes total internal reflection? -
correct answer ✅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.
Where would you expect Fresnel reflections to occur in a fiber-optic
network? -
correct answer ✅At connections and mechanical splices where the
signal source is entering or exiting the cable.
, NCTI Exam Fiber II Questions And Answers
Chromatic dispersion is a combination of which two dispersions? -
correct answer ✅Material and waveguide dispersion.
What is one advantage and one disadvantage of single-mode fiber
with a large mode field diameter (MFD)? -
correct answer ✅The larger the MFD, the easier it is to splice and
connectorize the fiber, although it becomes more sensitive to
bending losses.
What is the current standardized outside diameter (OD) of the
cladding of single-mode fiber? -
correct answer ✅It is 125 μm, with an accuracy of ±1 μm.
What do diameter differences between spliced fibers look like on
an optical time domain reflectometer (OTDR)? -
correct answer ✅Gain in one direction and high loss in the
opposite direction.
Besides protection, what else must the coating on an optical fiber
do? -
correct answer ✅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.
