1
Fiber Install & Activation
Conventional Questions and Correct
Answers
Question: Which of the following is true about fiber-optic cable? Choose
all that apply.
Answer: Because the optical fiber is made of dielectric material, the cable
does not carry electrical current, radiate energy, or produce heat or
sparks.
A 3/4-inch round fiber-optic cable can be manufactured with up to 864
optical fibers, which weigh approximately 130 pounds per kilometer.
Fiber-optic cable is affected less by moisture and thermal conditions than
is copper.
(2 attempts remaining)
Submit
Question: What is the wavelength of a 150 MHz carrier wave? Use the
speed of light measured in meters per second to finish this equation: 300
x 106 divided by 150 x 106.
Answer: 2 meters.
Question: The encoder portion of the ( data encoder/modulator) codes
analog signals for conversion into digitial signals and the modulator
portion transforms the digital signal into the appropriate modulation
format.
Answer: data encoder/modulator
Question: during the process of converting an electrical signal to an
optical signal, the (electrical interface) provides one or a combination of
any electrical protocols to the data encoder/modulator
Pretest - Stuvia US
,2
Answer: electrical interface
Question: the modulation signal is applied to the (light source) which
could be either a light emitting diode or laser diode.
Answer: light source
Question: What characteristic of fiber-optic cable enhances the security
of signals being transported in the network?
Answer: There is no EMI or RFI radiation, or other detectable energy,
radiating from the cable, so the transport of signal through fiber-optic
cable is very secure.
Question: An optical fiber consists of what three parts?
Answer: An optical fiber is made up of three parts: (1) the core, which
transports the majority of the optical signal; (2) the cladding, which
surrounds the core; and (3) the protective coating around the cladding.
Question: Chromatic dispersion occurs because each wavelength travels
through an optical fiber at slightly different velocities, and signals using
those wavelengths will arrive at the receive point at different times.
Answer: Fabry-Perot (F-P)
Question: One of the drawbacks of this laser is the emission of a
number of discrete wavelengths or side modes.
Answer: Fabry-Perot (F-P)
Question: These lasers are mainly sensitive to temperature variations
and require greater thermal control, which is provided by additional
circuitry.
Answer: Distributed feedback (DFB)
Question: current changes that occur during (direct modulation) causes
a slight change on the instantaneous wavelength of the generated light
from the optical source, called chirp, which is a major limitation.
Answer: direct modulation
Pretest - Stuvia US
, 3
Question: (Indirect modulation) virtually eliminates chirp, and provides
isolation from back reflections for improved relative intensity noise
performance
Answer: Indirect modulation
Question: during (Indirect modulation), optical power is constant, and
the choice of optical source can be made independent of the source's
ability to vary light intensity in proportion to the electrical modulation
signal.
Answer: Indirect modulation
Question: What does the spectral width of a laser or light emitting diode
(LED) define?
Answer: The spectral width or bandwidth of a laser or LED defines the
width of an optical emission at intersecting points of a line drawn across
the emission's signature profile, 3 dB (or 50%) down from the emission's
peak amplitude.
Question: What are the two methods used to modulate an optical
carrier?
Answer: Direct modulation and indirect modulation (also called external
modulation) are the two types of methods used to modulate an optical
carrier.
Question: Which of the following are factors that contribute to an optical
receiver's sensitivity? Choose all that apply.
Answer: noise, Linear response, back reflections
Question: with this diode, the amplification process introduces noise
into the electrical output of an optical detector.
Answer: Avalanche photodiode
Question: With this diode, the current flow is linear to the intensity of
light photons, as one electron/hole pair is created for every absorbed
photon until saturation.
Pretest - Stuvia US
Fiber Install & Activation
Conventional Questions and Correct
Answers
Question: Which of the following is true about fiber-optic cable? Choose
all that apply.
Answer: Because the optical fiber is made of dielectric material, the cable
does not carry electrical current, radiate energy, or produce heat or
sparks.
A 3/4-inch round fiber-optic cable can be manufactured with up to 864
optical fibers, which weigh approximately 130 pounds per kilometer.
Fiber-optic cable is affected less by moisture and thermal conditions than
is copper.
(2 attempts remaining)
Submit
Question: What is the wavelength of a 150 MHz carrier wave? Use the
speed of light measured in meters per second to finish this equation: 300
x 106 divided by 150 x 106.
Answer: 2 meters.
Question: The encoder portion of the ( data encoder/modulator) codes
analog signals for conversion into digitial signals and the modulator
portion transforms the digital signal into the appropriate modulation
format.
Answer: data encoder/modulator
Question: during the process of converting an electrical signal to an
optical signal, the (electrical interface) provides one or a combination of
any electrical protocols to the data encoder/modulator
Pretest - Stuvia US
,2
Answer: electrical interface
Question: the modulation signal is applied to the (light source) which
could be either a light emitting diode or laser diode.
Answer: light source
Question: What characteristic of fiber-optic cable enhances the security
of signals being transported in the network?
Answer: There is no EMI or RFI radiation, or other detectable energy,
radiating from the cable, so the transport of signal through fiber-optic
cable is very secure.
Question: An optical fiber consists of what three parts?
Answer: An optical fiber is made up of three parts: (1) the core, which
transports the majority of the optical signal; (2) the cladding, which
surrounds the core; and (3) the protective coating around the cladding.
Question: Chromatic dispersion occurs because each wavelength travels
through an optical fiber at slightly different velocities, and signals using
those wavelengths will arrive at the receive point at different times.
Answer: Fabry-Perot (F-P)
Question: One of the drawbacks of this laser is the emission of a
number of discrete wavelengths or side modes.
Answer: Fabry-Perot (F-P)
Question: These lasers are mainly sensitive to temperature variations
and require greater thermal control, which is provided by additional
circuitry.
Answer: Distributed feedback (DFB)
Question: current changes that occur during (direct modulation) causes
a slight change on the instantaneous wavelength of the generated light
from the optical source, called chirp, which is a major limitation.
Answer: direct modulation
Pretest - Stuvia US
, 3
Question: (Indirect modulation) virtually eliminates chirp, and provides
isolation from back reflections for improved relative intensity noise
performance
Answer: Indirect modulation
Question: during (Indirect modulation), optical power is constant, and
the choice of optical source can be made independent of the source's
ability to vary light intensity in proportion to the electrical modulation
signal.
Answer: Indirect modulation
Question: What does the spectral width of a laser or light emitting diode
(LED) define?
Answer: The spectral width or bandwidth of a laser or LED defines the
width of an optical emission at intersecting points of a line drawn across
the emission's signature profile, 3 dB (or 50%) down from the emission's
peak amplitude.
Question: What are the two methods used to modulate an optical
carrier?
Answer: Direct modulation and indirect modulation (also called external
modulation) are the two types of methods used to modulate an optical
carrier.
Question: Which of the following are factors that contribute to an optical
receiver's sensitivity? Choose all that apply.
Answer: noise, Linear response, back reflections
Question: with this diode, the amplification process introduces noise
into the electrical output of an optical detector.
Answer: Avalanche photodiode
Question: With this diode, the current flow is linear to the intensity of
light photons, as one electron/hole pair is created for every absorbed
photon until saturation.
Pretest - Stuvia US
