Fiber Installation and Activation
Exam 2025/2026 COMPLETE QUESTIONS
WITH VERIFIED CORRECT SOLUTIONS ||
100% GUARANTEED PASS
<LATEST VERSION>
1. Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm?
- ANSWER ✓ To take advantage of the low intrinsic absorption and lower
attenuation at 1550 nm in single-mode fiber
2. What type of single-mode fiber is intended for fiber-to-the-home
installations? - ANSWER ✓ The ITU-T G.657 bend-insensitive fiber (BIF)
3. What are the primary causes of intrinsic loss in single-mode fiber? -
ANSWER ✓ Material absorption and Rayleigh scattering.
4. Wide wavelength division multiplexing (WWDM) - ANSWER ✓ This
multiplexing process does not need to use expensive or sophisticated lasers
and optical detectors.
5. Dense wavelength division multiplexing (DWDM) - ANSWER ✓ During
this multiplexing process, the wavelength spacing is typically specified by
gigahertz (GHz) instead of wavelengths.
6. Wavelength division multiplexing (WDM) - ANSWER ✓ During this
multiplexing process, the optical output from multiple lasers operating at
different wavelengths is combined and transported over a single, common
optical fiber.
,7. Wide wavelength division multiplexing (WWDM) - ANSWER ✓ This
multiplexing process does not need to use expensive or sophisticated lasers
and optical detectors.
8. What are the three categories of WDM that are defined by the ITU? -
ANSWER ✓ The ITU defines three categories of WDM: wide wavelength
division multiplexing (WWDM), coarse wavelength division multiplexing
(CWDM), and dense wavelength division multiplexing (DWDM).
9. How might WWDM be used in a passive optical network (PON)
application? - ANSWER ✓ In a PON application, the 1,550 nm and 1,490
nm wavelengths could be used to transport television and HSD signals
throughout the network, and the 1,310 nm wavelengths could be used to
transport HSD signals from the connected premises to the headend.
10.What does the 20 nm wavelength spacing, specified in the ITU G.694.2
standard, allow? - ANSWER ✓ allows for wavelength variation around the
nominal wavelength, which can result when using uncooled distributed
feedback (DFB) lasers.
11.What two types of dispersion make up chromatic dispersion? - ANSWER ✓
material dispersion and waveguide dispersion
12.Which type of optical detection involves a photodiode that converts the light
waves to an electrical signal that varies in proportion to intensity changes in
the light waves? - ANSWER ✓ Direct
13.The frame structure of a synchronous transport signal (STS) is divided into
two parts. What are they? - ANSWER ✓ The transport overhead, which
contains the section and line layers, and the synchronous payload envelope,
which contains the path overhead and the payload data.
14.Coarse wavelength division multiplexing (CWDM) applications were
expanded to include use in what band, where a large OH absorption loss
occurred with older single-mode fibers? - ANSWER ✓ E band
,15.What variations of the star topology are used in PONs? - ANSWER ✓
Centralized split, distributed star, and home-run are variations of the star
topology used in PONs.
16.What are the main elements of an optical transmitter? - ANSWER ✓ The
main elements of an optical transmitter consist of an electrical interface, a
data encoder/modulator, a laser, and an optical interface.
17.What amplitude should quadrature amplitude modulation (QAM) be
adjusted to in an optical transmitter? - ANSWER ✓ Most optical transmitter
manufacturers specify that QAM carriers should be 6 to 10 dB below the
analog video carriers.
18.The phenomenon, total internal reflection, is what enables an optical fiber to
guide light. What characteristic of optical fiber causes total internal
reflection? - 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.
19.Where would you expect Fresnel reflections to occur in a fiber-optic
network? - ANSWER ✓ At connections and mechanical splices where the
signal source is entering or exiting the cable.
20.Chromatic dispersion is a combination of which two dispersions? -
ANSWER ✓ Material and waveguide dispersion.
21.What is one advantage and one disadvantage of single-mode fiber with a
large mode field diameter? - ANSWER ✓ The larger the MFD, the easier it
is to splice and connectrorize the fiber, although it becomes more sensitive
to bending losses.
22.What is the current standardized outside diameter of the cladding of single-
mode fiber? - ANSWER ✓ It is 125 µm, with an accuracy of ±1 µm.
23.What do diameter differences between spliced fibers look line on an optical
time domain reflectometer? - ANSWER ✓ Gain in one direction and high
loss in the opposite direction.
, 24.What is the Fiber-optic cable term for optical transport that is restricted to
one path (mode) for light propagation through the core of an optical fiber? -
ANSWER ✓ Single Mode Fiber
25.A type of optical fiber with large core diameters which allow multiple
modes, or paths, upon which the optical signal travels is known as what? -
ANSWER ✓ Multi - Mode Fiber
26.In fiber-optic terminology, what is "window" ? - ANSWER ✓ Refers to a
center optical wavelength, as well as a range of wavelengths on either side
of the center wavelength
27.What are the four standard optical windows? - ANSWER ✓ 850 nm, 1,300
nm, 1,550 nm, and 1,625 nm.
28.What window is exclusively used for multimode fiber? - ANSWER ✓ 850
nm
29.What is an Erbium-doped fiber amplifier (EDFA)? - ANSWER ✓ An optical
amplifier that uses active erbium-doped fiber and a pump source (laser) to
boost or amplify the optical signal?
30.What are the three basic components of all fiber-optic communications
networks? - ANSWER ✓ (1) an optical transmitter with a light source; (2)
the optical fiber (3) an optical receiver with a photodetector.
31.What characteristic of a fiber-optic cable enhances the security of signals
being transported in the network? - ANSWER ✓ Fiber optics are typically
made of glass which is a dielectric material which is basically immune to
EMI and RFI
32.What telecommunication standard designation encompasses all things voice,
video, and data? - ANSWER ✓ ITU Telecommunications Standardization
Sector ITU-T
33.Single -mode fiber-optic cable is optimized to transport which wavelengths?
- ANSWER ✓ 1310 nm & 1550 nm
Exam 2025/2026 COMPLETE QUESTIONS
WITH VERIFIED CORRECT SOLUTIONS ||
100% GUARANTEED PASS
<LATEST VERSION>
1. Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm?
- ANSWER ✓ To take advantage of the low intrinsic absorption and lower
attenuation at 1550 nm in single-mode fiber
2. What type of single-mode fiber is intended for fiber-to-the-home
installations? - ANSWER ✓ The ITU-T G.657 bend-insensitive fiber (BIF)
3. What are the primary causes of intrinsic loss in single-mode fiber? -
ANSWER ✓ Material absorption and Rayleigh scattering.
4. Wide wavelength division multiplexing (WWDM) - ANSWER ✓ This
multiplexing process does not need to use expensive or sophisticated lasers
and optical detectors.
5. Dense wavelength division multiplexing (DWDM) - ANSWER ✓ During
this multiplexing process, the wavelength spacing is typically specified by
gigahertz (GHz) instead of wavelengths.
6. Wavelength division multiplexing (WDM) - ANSWER ✓ During this
multiplexing process, the optical output from multiple lasers operating at
different wavelengths is combined and transported over a single, common
optical fiber.
,7. Wide wavelength division multiplexing (WWDM) - ANSWER ✓ This
multiplexing process does not need to use expensive or sophisticated lasers
and optical detectors.
8. What are the three categories of WDM that are defined by the ITU? -
ANSWER ✓ The ITU defines three categories of WDM: wide wavelength
division multiplexing (WWDM), coarse wavelength division multiplexing
(CWDM), and dense wavelength division multiplexing (DWDM).
9. How might WWDM be used in a passive optical network (PON)
application? - ANSWER ✓ In a PON application, the 1,550 nm and 1,490
nm wavelengths could be used to transport television and HSD signals
throughout the network, and the 1,310 nm wavelengths could be used to
transport HSD signals from the connected premises to the headend.
10.What does the 20 nm wavelength spacing, specified in the ITU G.694.2
standard, allow? - ANSWER ✓ allows for wavelength variation around the
nominal wavelength, which can result when using uncooled distributed
feedback (DFB) lasers.
11.What two types of dispersion make up chromatic dispersion? - ANSWER ✓
material dispersion and waveguide dispersion
12.Which type of optical detection involves a photodiode that converts the light
waves to an electrical signal that varies in proportion to intensity changes in
the light waves? - ANSWER ✓ Direct
13.The frame structure of a synchronous transport signal (STS) is divided into
two parts. What are they? - ANSWER ✓ The transport overhead, which
contains the section and line layers, and the synchronous payload envelope,
which contains the path overhead and the payload data.
14.Coarse wavelength division multiplexing (CWDM) applications were
expanded to include use in what band, where a large OH absorption loss
occurred with older single-mode fibers? - ANSWER ✓ E band
,15.What variations of the star topology are used in PONs? - ANSWER ✓
Centralized split, distributed star, and home-run are variations of the star
topology used in PONs.
16.What are the main elements of an optical transmitter? - ANSWER ✓ The
main elements of an optical transmitter consist of an electrical interface, a
data encoder/modulator, a laser, and an optical interface.
17.What amplitude should quadrature amplitude modulation (QAM) be
adjusted to in an optical transmitter? - ANSWER ✓ Most optical transmitter
manufacturers specify that QAM carriers should be 6 to 10 dB below the
analog video carriers.
18.The phenomenon, total internal reflection, is what enables an optical fiber to
guide light. What characteristic of optical fiber causes total internal
reflection? - 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.
19.Where would you expect Fresnel reflections to occur in a fiber-optic
network? - ANSWER ✓ At connections and mechanical splices where the
signal source is entering or exiting the cable.
20.Chromatic dispersion is a combination of which two dispersions? -
ANSWER ✓ Material and waveguide dispersion.
21.What is one advantage and one disadvantage of single-mode fiber with a
large mode field diameter? - ANSWER ✓ The larger the MFD, the easier it
is to splice and connectrorize the fiber, although it becomes more sensitive
to bending losses.
22.What is the current standardized outside diameter of the cladding of single-
mode fiber? - ANSWER ✓ It is 125 µm, with an accuracy of ±1 µm.
23.What do diameter differences between spliced fibers look line on an optical
time domain reflectometer? - ANSWER ✓ Gain in one direction and high
loss in the opposite direction.
, 24.What is the Fiber-optic cable term for optical transport that is restricted to
one path (mode) for light propagation through the core of an optical fiber? -
ANSWER ✓ Single Mode Fiber
25.A type of optical fiber with large core diameters which allow multiple
modes, or paths, upon which the optical signal travels is known as what? -
ANSWER ✓ Multi - Mode Fiber
26.In fiber-optic terminology, what is "window" ? - ANSWER ✓ Refers to a
center optical wavelength, as well as a range of wavelengths on either side
of the center wavelength
27.What are the four standard optical windows? - ANSWER ✓ 850 nm, 1,300
nm, 1,550 nm, and 1,625 nm.
28.What window is exclusively used for multimode fiber? - ANSWER ✓ 850
nm
29.What is an Erbium-doped fiber amplifier (EDFA)? - ANSWER ✓ An optical
amplifier that uses active erbium-doped fiber and a pump source (laser) to
boost or amplify the optical signal?
30.What are the three basic components of all fiber-optic communications
networks? - ANSWER ✓ (1) an optical transmitter with a light source; (2)
the optical fiber (3) an optical receiver with a photodetector.
31.What characteristic of a fiber-optic cable enhances the security of signals
being transported in the network? - ANSWER ✓ Fiber optics are typically
made of glass which is a dielectric material which is basically immune to
EMI and RFI
32.What telecommunication standard designation encompasses all things voice,
video, and data? - ANSWER ✓ ITU Telecommunications Standardization
Sector ITU-T
33.Single -mode fiber-optic cable is optimized to transport which wavelengths?
- ANSWER ✓ 1310 nm & 1550 nm
