12) | QUESTIONS AND ANSWERS | 2025/26 UPDATE |
WITH COMPLETE SOLUTION
What advantage is realized by increasing the voltage in a broadband cable
network from 60 volts alternating current (VAC) to 90 volts? Answer -
Operating with 50% more voltage reduces the voltage drop and current drawn
in the network for more efficient power utilization.
How does surge protection at the input and output of a ferroresonant power
supply defend against voltage surges? Answer - By passing voltage surges
(within the surge device rating) to ground without damage.
Which part of a ferroresonant transformer regulates the load on the secondary
winding? Answer - The magnetic shunt.
In a standby network power supply, what comes online to convert the battery
voltage to alternating current (AC), which then goes to the ferroresonant
transformer? Answer - The battery-powered inverter.
In a power inserter with three filtering networks, what is the purpose of the
high-pass filter? Answer - To prevent the 60 hertz (Hz) alternating current (AC)
from passing between the two radio frequency (RF)/AC ports.
, What inserts alternating current (AC) into the network with a direct connection
to an amplifier rather than using a power inserter? Answer - The amplifier AC
circuitry.
What is the advantage for supplying alternating current (AC) to multiple
amplifiers from one network power supply? Answer - Allows the designer to
place amplifiers without concern about access to electrical utility power.
Where is a clamp-on ammeter attached to measure the output current from a
network power supply? Answer - Clamped around the conductor attached to
the lug that tightens down on the coaxial cable connector pin.
What is a priority in any standby power supply maintenance program? Answer
- Battery care.
What is the voltage into the second amplifier in cascade, if each amplifier
draws 1.5 amps of current, the loop resistance of each section of cable is 1.38
ohms, and the alternating current (AC) source is a 90 volts AC (VAC) network
power supply? Answer - 83.77 VAC.
What enables set-top boxes (STB) and Data Over Cable Service Interface
Specification (DOCSIS) modems to operate as completely separate systems that
operate independent of each other? Answer - STB and DOCSIS modems are
assigned different upstream channels with dedicated receivers in the headend.
What did the 1.1 version of the Data Over Cable Service Interface Specification
(DOCSIS) introduce, incorporating solutions for transporting real-time data
applications (such as voice traffic) over the cable operator's managed IP
network, and doing so with quality comparable to that of the telephone
company? Answer - PacketCable.