ROC Fundamentals Practice Exam

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• What is the input-to-output power ratio of a coaxial cable that has 1 dB of attenuation?
• When is the return path considered to be properly balanced with unity gain?
• What is a major benefit of using fiber-optic cables in telecommunications?
• What should be confirmed before diagnosing a return path problem in the drop system?
• What is the primary function of a line extender housing?
• Which of the following is NOT a component of the tap housing?
• What does the Zero Span function on a spectrum analyzer accomplish?
• What is a key consequence of signals arriving back at the source with a delay in a network?
• Which factor can affect the input signal level that needs to be compensated for by the controls?
• Where is the first equalizer located in the forward signal path of a line extender?
• At which wavelength should a laser emit to amplify a signal in a fiber-optic network for long distances?
• What does 1 dB represent in relation to bel?
• Which version of DOCSIS introduced features to boost both downstream and upstream data throughput?
• In a monitored network, what is likely to occur when identifying micro-reflections?
• After splicing a fiber-optic cable, what tool is recommended for picking up fiber pieces?
• Why is the use of dBmV acceptable for expressing power per Hz across channel bandwidth?
• What is the primary function of a tap port leg in a directional coupler?
• To calculate the output port and tap port signal levels in dBmV, what is essential to reference?
• Which testing device is the best to use to measure cable faults?
• What is the purpose of a signal level meter?
• Which modulation technique aids in reliably receiving STB upstream carriers below 20 MHz?
• Which technology automatically records the location of leakage data to a specific street address?
• What advanced Physical Layer (PHY) technology added to DOCSIS 2.0 includes byte interleaving?
• What is the typical input configuration of most line extender housings?
• Why is data throughput over the upstream path typically lower than that of the downstream path in a DOCSIS network?
• Why is the correct tightening sequence important when closing amplifier housings?
• What access schemes were introduced with advanced Physical (PHY) Layer technologies in DOCSIS 2.0?
• If a leak is located at an amplifier, which type of antenna is best for identifying the exact source?
• What standard symbol is used for a two-way tap on cable system design maps?
• What is the relationship between voltage ratio and power ratio?
• From where do DOCSIS modems obtain their configuration files and billing messages?
• In which applications are avalanche photodiodes (APD) most commonly utilized?
• For a two-way splitter with 132 feet of Series 6 cable, how much signal is needed from the subscriber's tap port @ 750 MHz to ensure each TV set receives a minimum of +3.0 dBmV?
• What is an advantage of utilizing the Max Hold function on a spectrum analyzer?
• What is the primary role of a return amplifier?
• How is a fraction converted to a percentage?
• What is the standard loss attributed to a splitter in a signal distribution system?
• Why is it advisable to troubleshoot impulse noise at distribution taps of 17 dB or lower?
• If the isolation value between tap and output ports is higher, what is the benefit?
• What role do diplex filters play in a two-way amplifier module?
• Why are RF return channel carriers ineffective for aligning return path equipment?
• What characteristic signals the need for a preamplifier in measurements?
• What is one of the initial steps in the six-step troubleshooting process?
• What amplitude level should the output of return amplifiers be adjusted to match?
• What are two new features added in DOCSIS 3.1 to enhance HFC networks?
• Which of the following devices is considered an active device?
• What is the return signal pass band frequency used in most of North America?
• What device can be used alongside a signal level meter (SLM) to check the drop system for RF continuity?
• What should be done about frequency response variations of less than 1 dB in injected test carriers?
• What is the output port signal level at 547.25 MHz if the input signal is 35.0 dBmV and the insertion loss is 1.4 dB?
• What is the uV/m level of a -37 dBmV signal leakage measurement at 127.2625 MHz?
• Which component is not typically found in a standard coaxial cable?
• How many decimal values can eight bits of data represent?
• What role does a signal generator play in testing the drop system?
• What is one of the main purposes of monitoring signal leakage in cable systems?
• In which version of DOCSIS was an option introduced to increase the upstream spectrum frequency to 85 MHz?
• What is the function of cladding in a fiber optic cable?
• What is the function of the terminating tap in a cable system?
• How does IP multicast differ from IP broadcast?
• What essential components are typically found on a power inserter faceplate?
• How does DOCSIS proactive network maintenance (PNM) assist technicians in troubleshooting?
• How is impulse noise characterized when observed on a spectrum analyzer?
• The code words and spreading algorithm of synchronous code division multiple access (S-CDMA) enable simultaneous transmission of up to how many modems on the same RF return channel?
• Calculate the capacitive reactance of a power inserter's capacitor at 60 Hz with a capacitance of 1,000 pF. What is the reactance?
• A 1 mV decrease in a signal level of 40 dBmV is approximately equivalent to a decrease in level of how many decibels?
• To provide a minimum of 3.0 dBmV to the TV set when using 150 feet of Series 6 cable, how much signal is necessary from the subscriber's tap port @ 750 MHz?
• What does the tap port RF signal level refer to in a tap?
• In a return path system, what is the significance of equalizing path attenuation?
• What tool can be used to verify the calibration of a leakage detector?
• What action should be taken upon identifying the location of electrical interference in the power network?
• Which measurement provides a comparison free of bandwidth errors?
• What is the main goal of the Data Over Cable Service Interface Specification (DOCSIS) certification process?
• What is the purpose of using house amplifiers with a passive return path?
• What access technology is utilized by DOCSIS 1.0 for sending data upstream?
• Why are high-pass filters (HPF) considered a short-term solution at tap points for drops?
• Why do DOCSIS networks have asymmetrical data throughput rates?
• What does the term 'signal attenuation' refer to in the context of directional couplers?
• Which media access control (MAC) protocols are specified for digital set-top boxes (STB)?
• What is indicated by the performance of a network monitoring system in relation to the group delay?
• What is the function of an interdiction unit?
• What is indicated by a reduced signal attenuation in coaxial cables at sub-band frequencies?
• Why are 6 MHz and 41 MHz chosen as test carriers for return path spectrum?
• Where is common path distortion (CPD) typically most severe in a network?
• In terms of data transmission, what advantage does fiber-optic technology have over traditional copper cables?
• What adjusts the carrier amplitude to correct for unequal path attenuation in the RF return path?
• Which of the following describes a decibel (dB)?
• Which layers of the OSI reference model are relevant between DOCSIS modems and the cable modem termination system (CMTS)?
• What evolved due to the introduction of switched digital video (SDV) that highlighted limitations of legacy HFC networks?
• How should the bolts be tightened on a distribution amplifier housing?
• What is the primary function of the return amplifier in RF systems?
• What is the percentage equivalent of a 1:5 ratio?
• Which of the following is used to define the waveform of an optical signal?
• When aligning the optical return path, what should be the ideal characteristic of the test signal?
• What do signal level controls compensate for in an amplifier?
• What characterizes a micro-reflection in signal analysis?
• What organization approved the first version of the Data Over Cable Service Interface Specification (DOCSIS) as an international standard?
• What feature does an RF/AC bypass tap provide?
• Which optical band is primarily used for optical amplifiers due to its low attenuation loss?
• What allows set-top boxes (STB) and DOCSIS modems to function as independent systems?
• What is the primary function of a directional tap?
• What is the definition of tap-to-tap isolation?
• Which component of a fiber-optic system is primarily responsible for guiding light?
• What is the correct sequence of fiber-optic network architecture up to customer premises?
• Where should injected sweep pulses be positioned to avoid interference?
• What is the primary purpose of PacketCable?
• What does the term 'ingress' refer to in the cable system?
• What information can be provided by a return path monitoring system from a DOCSIS modem?
• What complication can arise from high levels of ingress in a cable system?
• Which frequency bands are designated for aeronautical use?
• What is the effect of increasing output port insertion loss on the signal level?
• At what frequency is the insertion loss of a two-way feed-through tap measured?
• What power ratio does 2 bels represent for a coaxial cable of similar impedance?
• What is the attenuation loss through the hot-leg of an unbalanced three-way splitter at sub-split frequencies?
• When should a preamplifier be used with a spectrum analyzer to measure impairments?
• What is the recommended method for closing a distribution amplifier housing?
• Which statement is generally true regarding tap placement?
• What type of setup is typically required for long service drops in cable systems?
• Why does the output level from customer premises equipment (CPE) fluctuate?
• In a directional coupler, where is the signal power level higher?
• Why is the broadband cable industry developing a proprietary passive optical network (PON) standard?
• Which leakage measurement tool is specifically designed for improved accuracy in locating leaks?
• The impedance of coaxial cable is made up of which three electrical properties?
• When considering the attenuation rate of Series 6 coaxial cable, what is the specified rate at 750 MHz?
• What does it indicate if the ninth bar in a cable modem's PreEqualization Tap response is less than 10 dB below the eighth bar?
• According to the FCC, leaks of what measurement and above must be logged and repaired?
• What is a significant disadvantage of using optical fibers compared to copper wiring?
• A signal increase of 1 dB represents what approximate increase in power?
• How do plug-in connectors in a line extender amplifier housing function?
• Which of the following accurately describes a power inserter?
• The ratio of power represented by 1 bel can be expressed as what numerical ratio?
• What is the power ratio equivalent for 2 dB?
• Why is a constant bit rate (CBR) telephone system classified as circuit-switching technology?
• Which of the following is the distance occupied by 1 hertz (Hz)?
• Which of the following is NOT a type of leak detection tool commonly used?
• In mathematics, what is a fraction defined as?
• Why is the E band considered undefined for fiber-optic communications?
• What does 'MER' stand for in the context of cable modem performance?
• Which location experiences the highest levels of forward and lowest levels of return in a network?
• What occurs when light strikes a medium at an angle less than the critical angle?
• What Internet Protocol address modes can a DOCSIS 3.0 and 3.1 modem be provisioned in?
• How is the signal loss expressed in a tap at a specific frequency?
• Which Data Over Cable Service Interface Specification (DOCSIS) layer is utilized by the CMTS to differentiate between cable modems?
• What do values expressed in dBmV that are preceded by a minus sign represent?
• What type of information must be included in the annual reporting to the FCC regarding signal leakage?
• What is the minimum modulation error ratio (MER) required into a cable modem for a 256-QAM carrier in a DOCSIS network?
• What benefit does a technician gain by asking the customer to demonstrate the problem?
• Which type of digital modulation contains four symbols with 2 bits in each symbol?
• Why is a leakage detector preferred over a standard signal meter for detecting leaks?
• What is the primary difference between coaxial express cable and coaxial distribution cable in an HFC architecture?
• Which method minimizes the amount of thermal noise added to a network?
• In an HFC architecture, what type of device serves as the connection point for splitting the signal to multiple drop locations?
• What symptoms indicate hum on an upstream digital modulation channel?
• What does a higher insertion loss value in a directional coupler indicate?
• What are the FCC requirements regarding leakage monitoring?
• What practice helps identify potential return path problems before they enter the network?
• Chipsets with ingress cancellation algorithms are most effective for removing impairments in which portion of the RF return frequency spectrum?
• Which step in the troubleshooting process involves discussing the issue with the customer to gather detailed information?
• What is the primary purpose of a seizure screw mechanism in tap housing?
• What is the effect of group delay in upstream transmissions?
• What limitation of Fabry-Perot (FP) lasers is resolved by distributed feedback (DFB) lasers?
• What is the implication of a power inserter block diagram design?
• Which spectrum analyzer function is useful for capturing and holding various impairments on its display?
• What is necessary to maximize performance in the optical return path for DOCSIS 3.1?
• What does a passive component do in the context of a distribution amplifier?
• How should you connect an optical time domain reflectometer (OTDR) to test a fiber-optic cable?
• Which three networks are included in the PacketCable 1.0 architecture?
• What modification in DOCSIS 3.0 allows for increased bandwidth for upstream carriers from earlier versions?
• What should be checked if set-top boxes transmit above 55 dBmV?
• What is the downstream throughput if two 256-QAM channels, each with a throughput of 38 Mbps, are bonded?
• What recourse do broadband cable operators have regarding interference from citizens band (CB) and ham radio signals?
• What does tap loss refer to in cable systems?
• What is a key characteristic of coaxial cables used in telecommunications?
• Why do values expressed in dBmV progress in a nonlinear fashion compared to a linear mV scale?
• In the term 10BaseT, what does the 'T' represent?
• What is the input port signal level for a four-way tap when the preceding tap's output is 25.0 dBmV?
• What was introduced in the DOCSIS 1.1 version for real-time data transport?
• What is operational gain in an amplifier?
• When is UTP cable preferred for use?
• What is the significance of using logarithmic values for power in telecommunications?
• Which of the following units can be used to represent signal level values?
• What system results from the "funneling effect"?
• What is the main issue if ingress or impulse noise is high enough in a network?
• What is critical regarding the upstream optical transmitter in a traditional analog return path?
• What must be ensured for each power inserter in system design regarding current requirements?
• Which technology will carry a signal the greatest distance without a repeater?
• What does the term "bel" refer to in telecommunications?
• What does a signal that is 3 dB lower than normal indicate?
• What is the purpose of an attenuator pad in a STB?
• What enhancements were made to DOCSIS that allowed cable operators to provide telephone services comparable to traditional phone companies?
• What is an erbium-doped fiber amplifier (EDFA) used for in fiber-optic networks?
• What does "bypass AC current capacity" refer to?
• What OSI model layers does the MAC Layer in DOCSIS encompass?
• What is typically required for the AC input voltage in a line extender amplifier?
• When comparing different sizes of directional couplers, what observation is typically made?
• What is a characteristic of orthogonal frequency division multiplexing (OFDM) channel subcarriers?
• In telecommunications, what does the term attenuation refer to?
• Why can the STB upstream carrier be positioned below 20 MHz?
• What installation method is best to use when laying fiber-optic cable over a path with short outbuildings and hedges?
• If the input-to-output power ratio is 10:1, what is the corresponding input-to-output voltage ratio?
• What does it mean if a cable has an attenuation of 3 dB?
• What is the resultant voltage if the signal is 0 dBmV?
• Which frequency choice minimizes signal distortion in the return path?
• What did DOCSIS 1.1 introduce to enhance quality of service management?
• What can cause variations in amplitude received from the injectors at the transceiver?
• When bonding the installation, which should be shorter if the bonding wire and the cable connecting to consumer electronics are the same size?
• Why is it important to minimize ingress and impulse noise in a network?
• How does the output signal level of the upstream receiver relate to changes in its input power?
• What is the AC input voltage of a power inserter when certain conditions are met?
• What is "fiber-to-the-home" (FTTH) used to describe in network deployment?
• Why would a three-way unbalanced splitter be used in a system design?
• What is the RF signal power remaining after a coaxial cable experiences 10 dB of attenuation?
• Which type of coupler allows any of its ports to serve as either input or output?
• What is the output port RF signal level for a two-way feed-through tap at 55.25 MHz?
• What is the maximum tap value that can be installed when connected directly to a line extender amplifier output rated at 45 dBmV?
• What is a key characteristic of a successful troubleshooter?
• Why is 38 MHz often the maximum frequency used for upstream modem transmissions?
• What does a minimum acceptable signal level of 0 dBmV represent at a TV set input?
• What is the tap loss at 547.25 MHz for a four-way terminating tap?
• During installations, what is critical to maintain to prevent signal degradation?
• What does a signal level meter (SLM) display as a delta measurement?
• What is a common application of packet cable technology introduced by DOCSIS?
• What does the term "attenuation" refer to in signal transmission?
• What type of noise appears as random spikes across a return path frequency spectrum?
• What happens to the data throughput when transitioning from quadrature phase shift keying (QPSK) to 16-QAM (quadrature amplitude modulation) in a channel of the same bandwidth?
• What is the primary purpose of the cladding in a fiber-optic cable?
• How does signal attenuation in the sub-band frequency spectrum compare to that at forward path frequencies?
• What happens if impulse noise is not managed effectively in a cable network?