NCTI ROC II BOOK II FINAL Test 1.
When pressure testing a drop system to check for leakage, What must be done before applying the
test signal?
The technician must isolate the drop system from the hybrid fiber/coax (HFC) network by disconnecting
the drop at the distribution tap.
Why do some leakage detection systems utilize a leakage carrier modulated with a tagging signal?
To avoid false detection of leaks.
When all three sections of a pulse code modulator (PCM) are combined, what function can be
performed?
· As an analog-to-digital converter (ADC)
What prevents the subcarriers in orthogonal frequency division multiplexing (OFDM) from interfering
with each other?
· The peak power of each subcarrier aligns with the minimum power of the adjacent subcarrier.
What two significant signals go into the mixer to create the intermediate frequency (IF)?
· The RF signal frequency at the output of the front-end filter and the local oscillator (LO) signal.
Which class of amplifier efficiency approaches, but never achieves, 100%?
· Class D amplifier.
What is the output waveform coming from a ferroresonant power supply?
· A quasi-square wave.
What instrument should be used to accurately measure the output voltage of a ferroresonant power
supply?
· A true root mean square (RMS) digital multimeter (DMM)
What could a light dimmer with a silicon controlled rectifier (SCR) create in a customer premises?
· Radio frequency interference (RFI).
What is a characteristic of a bipolar junction transistor (BJT) common emitter configuration?
· The output signal is taken from the emitter.
What is done to an operational amplifier (op amp) to create a low-pass filter circuit?
· A capacitor is placed in parallel with the feedback resistor that is connected to the op amp inverting
input (-).
, What is the core objective of the Data Over Cable Service Interface Specification (DOCSIS) Provisioning
of Ethernet passive optical network (EPON), or DPOE, access architecture?
· To make the EPON elements appear and operate as DOCSIS elements to the existing DOCSIS-based back
office provisioning operations.
What benefit does a power-doubling configuration offer compared to a single cascade push-pull hybrid
amplifier?
· Twice the output with the same distortion.
Which statement characterizes a distributed powering system?
· Uses multiple locations for power supply placement within the outside plant
What is done to an operational amplifier (op amp) to create a low-pass filter circuit?
· The number of inductors plus capacitances that are in a filter circuit
What is required for checking the physical network integrity when maintaining the coaxial cable
network?
· Being observant and performing some minor tasks while engaged in regularly scheduled activities.
Which type of map contains node information?
· Design map.
Why is the term "gain control" applied to amplifier gain and controls inaccurate?
· The only way to vary the output of any amplifier is to adjust the amplitude level of the signal going into
the amplifier.
When activating a fiber-optic network, which acceptance testing stage includes adjusting attenuation
levels for the first time?
· During equipment activation.
What is the thermal noise level used for reference in broadband cable noise calculations?
· -59.2 dBmV.
Which component of a digital optical network is used to receive digital modulation light waves and
convert them to an electrical signal?
· Optical transponder.
Why is sweeping an amplifier during alignment more accurate than rough balancing?
· Rough balanced amplifiers have large gaps of unobserved spectrum that could have frequency response
related issues.
When used together, which two optical amplifiers achieve very wide optical gain with a flattened
bandwidth for better, overall network performance?
When pressure testing a drop system to check for leakage, What must be done before applying the
test signal?
The technician must isolate the drop system from the hybrid fiber/coax (HFC) network by disconnecting
the drop at the distribution tap.
Why do some leakage detection systems utilize a leakage carrier modulated with a tagging signal?
To avoid false detection of leaks.
When all three sections of a pulse code modulator (PCM) are combined, what function can be
performed?
· As an analog-to-digital converter (ADC)
What prevents the subcarriers in orthogonal frequency division multiplexing (OFDM) from interfering
with each other?
· The peak power of each subcarrier aligns with the minimum power of the adjacent subcarrier.
What two significant signals go into the mixer to create the intermediate frequency (IF)?
· The RF signal frequency at the output of the front-end filter and the local oscillator (LO) signal.
Which class of amplifier efficiency approaches, but never achieves, 100%?
· Class D amplifier.
What is the output waveform coming from a ferroresonant power supply?
· A quasi-square wave.
What instrument should be used to accurately measure the output voltage of a ferroresonant power
supply?
· A true root mean square (RMS) digital multimeter (DMM)
What could a light dimmer with a silicon controlled rectifier (SCR) create in a customer premises?
· Radio frequency interference (RFI).
What is a characteristic of a bipolar junction transistor (BJT) common emitter configuration?
· The output signal is taken from the emitter.
What is done to an operational amplifier (op amp) to create a low-pass filter circuit?
· A capacitor is placed in parallel with the feedback resistor that is connected to the op amp inverting
input (-).
, What is the core objective of the Data Over Cable Service Interface Specification (DOCSIS) Provisioning
of Ethernet passive optical network (EPON), or DPOE, access architecture?
· To make the EPON elements appear and operate as DOCSIS elements to the existing DOCSIS-based back
office provisioning operations.
What benefit does a power-doubling configuration offer compared to a single cascade push-pull hybrid
amplifier?
· Twice the output with the same distortion.
Which statement characterizes a distributed powering system?
· Uses multiple locations for power supply placement within the outside plant
What is done to an operational amplifier (op amp) to create a low-pass filter circuit?
· The number of inductors plus capacitances that are in a filter circuit
What is required for checking the physical network integrity when maintaining the coaxial cable
network?
· Being observant and performing some minor tasks while engaged in regularly scheduled activities.
Which type of map contains node information?
· Design map.
Why is the term "gain control" applied to amplifier gain and controls inaccurate?
· The only way to vary the output of any amplifier is to adjust the amplitude level of the signal going into
the amplifier.
When activating a fiber-optic network, which acceptance testing stage includes adjusting attenuation
levels for the first time?
· During equipment activation.
What is the thermal noise level used for reference in broadband cable noise calculations?
· -59.2 dBmV.
Which component of a digital optical network is used to receive digital modulation light waves and
convert them to an electrical signal?
· Optical transponder.
Why is sweeping an amplifier during alignment more accurate than rough balancing?
· Rough balanced amplifiers have large gaps of unobserved spectrum that could have frequency response
related issues.
When used together, which two optical amplifiers achieve very wide optical gain with a flattened
bandwidth for better, overall network performance?
