Multiple Choice 2

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#01*. Modulation enables signals to be transmitted at frequencies a. Higher than the original b. Lower than the original c. In the vf range d. In the hf range: A. Higher than the original
#02*. What purpose of modulation involves modulating low frequency signals for transmission over long distances? a. Spectrum conservation b. Channel allocation c. Ease of radiation d. Companding: C. Ease of radiation
#03. What factor determines the spacing of the sidebands in an amplitude modulated signal? a. Amplitude of the modulationg signal b. Amplitude of the carrier signal c. Frequency of the modulating signal d. Frequency of the carie: C. Frequency of the modulating signal
#04*. The relationship of the bandwidth required for dsbec am to the bandwidth of the modulating signal of the am bandwidth alone is a. one quarter of the modulating bandwidth b. half the modulating bandwidth c. twice the modulating: C. twice the modulating bandwidth
#05. what type of device is used to recover the intelligence signal in dsbsc modulation? a. Envelope detector b. High pass filter c. Low pass filter d. Heterodyne detector: D. Heterodyne detector
#06. In double sideband suppressed carrier modulation, the intelligence is reconstructed by modulating the received signals at the exact frequency and phase relation as the a. modulation frequency b. lower sideband c. carrier freque: C. carrier frequency
#07. What is the relationship of the ssbsc bandwidth comapared to dsbec or dsbsc signals? a. SSBSC requires half the bandwidth of the other two b. SSBSC requires twice the bandwidth of the other two c. SSBSC requires half the bandwid: A. SSBSC requires half the bandwidth of the other two
#08. The output of the oscillator in a FM modulator increases in frequency with each a. positive half cycle of the carrier b. negative half cycle of the carrier c. positive half cycle of the modulating signal d. negative half cycle of: C. positive half cycle of the modulating signal
#09. In FM, the amount of oscillator frequency change is a. inversely proportional to the amplitude of the modulating signal b. directy proportional to the amplitude of the modulation signal c. inversely proportional to the phase of: B. directy proportional to the amplitude of the modulation signal
#10. A 10khz modulating signal has enough peak voltage to cause a deviation of 30khz. What is the modulation index? a. 5 b. 0.5 c. 0.3 d. 3: D. 3
#11. How many sidbands does FM produce? a. 360 b. A finite number c. An unlimited number d. 1 percent of the carrier frequency: C. An unlimited number
#12*. In PM, the carriers a. phase is shifted at the rate of the modulating signal b. phase shifted with the phase of the modulating signal c. amplitude is shifted at the rate of the modulating signal d. amplitude is shifted wit: A. phase is shifted at the rate of the modulating signal
#13. By using 8-psk instead of binary phase shift keying, information capacity is increased a. twice b. three times c. four times d. five times: B. three times
#14*. What is the first step in the pulse code modulation process? a. Discrete amplitudes are assigned to the sampling pulses b. the analog signal is band limited c. A binary code number is assigned to the sample d. The quantize: B. the analog signal is band limited
#15. Non uniform quantizing and companding decreases the length of the code word from a. 11 to 7 bits b. 11 to 8 bits c. 16 to 7 bits d. 16 to 8 bits: A. 11 to 7 bits
#16. How fast can an asynchronous transfer mode network potentially move data? a. 300 mbps b. 400 mbps c. 600 mbps d. 500 mbps: C. 600 mbps
#17*. How does synchronous transmission reduce the overhead costs of data transmission? a. Communicates in parallel fomat b. Blocks many characters together for transmission c. Elimintates the control bits, so more message data can b: B. Blocks many characters together for transmission
#18*. Which RS-232C signal is the data from the data communications equipment to the data terminal equipment? a. Ring indicator b. Carrier detect c. Recieve data d. Transmit data: C. Recieve data
#19. Which rs-232c signal indicates the modem is ready to transfer data? a. Clear to send b. Data set ready c. Request to send d. Data terminal ready: B. Data set ready
#20. The minimum pins required to establish a two-way data communications path with the RS-232 standard are a. Pins 2, 3, and 6 b. Pins 2, 5, and 7 c. Pins 2, 3, and 5 d. Pins 2, 3, and 7: D. Pins 2, 3, and 7
#21. Which standard designates the electrical standards for a balanced voltage digital interface circuit? a. RS-422 b. RS-423 c. RS-449 d. RS-530: A. RS-422
#22. What is the transition region voltage in an RS-422 line driver? a. -0.2 to +0.2 b. -0.3 to +0.3 c. -2.0 to +2.0 d. -3.0 to +3.0: C. -2.0 to +2.0
#23. Which standard uses many of the same pins and functions as RS-232? a. RS-422 b. RS-423 c. RS-449 d. RS-530: D. RS-530
#24*. Approximately what percentage of all network problems are cable related according to the National Association of Communications Contractors? a. 50 percent b. 60 percent c. 70 percent d. 80 percent: C. 70 percent
#25*. When using vertical redundancy check, what significance does the amount of ones have in a data bit pattern? a. Determines parity b. Determines transmission rate c. Determines whether transmission is in ASC11 format d. Dete: A. Determines parity
#26*. Using the longitude redundancy check method of error correction, what does receiver compare with the transmitter to ensure an accurate transmission of data? a. The checksum b. Block check character c. The ASC11 character set: B. Block check character
#27. What two error detection methods, when used together, are 98 percent effective in detecting errors? a. Checksome and cyclic redundancy check b. Longitudinal redundancy check and check sum c. Cyclic redundancy check and vertical: D. Vertical redundancy check and longitudinal redundancy check
#28*. What is the most common error correction technique? a. Automatic retransmit on request b. A combination of a, c, and d c. Block check character matrix d. Forward error control: A. Automatic retransmit on request
#29 When using forward error control as a method of error correction, where does error correction take place? a. Receiving end b. Transmitting end c. Both a and b d. Neither a nor b: A. Receiving end
#30*. Which statement describes an advantage of using fiber optic cable a. The easy tap-ability of fiber optic cables presents security risks b. Fiber Optic cable has a higher attenuation than coaxal cable c. Electromagnetic fields d: C. Electromagnetic fields do not affect fiber optic cables
#31. The designation of one-millionth of meter is a. kilometer b. nanometer c. Newton d. Micron: D. Micron
#32*. Most fiber optic links use infrared light that has a frequency range of about a. 400 to 750 nm b. 750 to 1500 nm c. 600 to 1200 mm d. 700 to 1800 mm: B. 750 to 1500 nm
#33*. What two important facts must be considered when light is propagated through a prism or fiber? a. The refractive index and angle at which the light strikes the junction b. The speed of light as it strikes the material and the refrac: A. The refractive index and angle at which the light strikes the junction
#34*. A knowledge of the principles of refraction includes the normal, angle of refraction, and a. critical angle b. refractive indices c. angle of indices d. angle of reflection: C. angle of indices
#35. Propagation of light as seen by Snells law is known as a. total internal reflection b. Refraction of light c. light wavelengths d. rays of incidence: A. total internal reflection
#36*. How is attenuation measured in fiber optics? a. Power in-power out b. Nanometers per second c. Nanoseconds per kilometer d. Decibels per kilometer: D. Decibels per kilometer
#37*. The two main causes of attenuation in a fiber optic result from absorption and a. power loss b. nuclear loss c. rayleigh scattering d. different refractive indices: C. rayleigh scattering
#38. The most useful way to classify fiber optic cables is by a. fiber material and number of fibers b. buffer type and application method c. numerical aperture and cable elements d. refractive index profile and number of modes: D. refractive index profile and number of modes
#39*. In fiber optics a mode can best be described as a. a mathematical theory b. the axial ray of the fiber c. the cores length of a fiber d. the path light travels down fiber: D. the path light travels down fiber
#40. Which classification type of fiber optical cable has the highest dispersion throughout its length? a. Multimode step-index b. Multimode graded-index c. Single-mode step-index d. Single-mode graded-inded: A. Multimode step-index
#41. A fiber optic cable in which the core has numerous concentric layers of glass is classified as a. multimode step-index b. single-mode step-index c. multimode core-index d. multimode graded-index: D. multimode graded-index
#42. What type of buffer allows the fiber optic cable to be twisted or pulled with little stress on the fiber? a. Ribbon b. Composite c. Tight tube d. Loose tube: D. Loose tube
#43*. What outer jacket material used on fiber optic cables has a low resistance to sunlight and abrasion? a. Neoprene b. Polyurethane c. Polyethylene d. Polyvinyl chloride: D. Polyvinyl chloride
#44. The basic building block of a breakout cable is known as the a. unit b. subunit c. superunit d. buffered fiber: B. subunit
#45. What components make up a complete basic fiber optic link (exclude fiber connections)? a. Emitter, optic fiber, detector b. Source, optic fiber, encoder, and an output circuit c. Transmitter, driver, amplifier, optic fiber, and: D. Driver, source, optic fiber, detector, and an output circuit
#46. Two types of light sources for fiber optic modems are light-emitting diodes and a. photo transistors b. hybrid photodiods c. semiconductor laser diodes d. integrated photodiode/preamplifiers: C. semiconductor laser diodes
#47*. What is one of the requirements a light source must have to be beneficial? a. Circuitry must have temperature control capabilities. b. Risetime must be fast enough to meet bandwidth requirements c. Have a wide bend of wavelengt: B. Risetime must be fast enough to meet bandwidth requirements
#48. What type of emitter has an "etched well" created in the N-type gallium aluminum arsenide material? a. Edge b. Laser c. Surface d. Injection laser: C. Surface
#49. What is the PN junction called in a light emitting diode where photons are emanated? a. Active region b. Valance band c. Conduction band d. Depletion region: D. Depletion region
#50. What type of current is produced by a photo detector when no light is present? a. Electrical b. Quantum c. Photon d. Dark: D. Dark
#51*. The responsivity of a photodetector is dependent on the a. risetime of emitter b. wavelength of light c. signal-to-noise ratio d. modulation speed of emitter: B. wavelength of light
#52. What photodetector converts one photon to one electron? a. Integrated photodiode/preamplifier b. Light emitting diode c. Avalanche photodiode d. Positive intrinsic negative: D. Positive intrinsic negative
#53*. Which fiber optic cable configuration consists of multifiber cables? a. Splices b. Pigtails c. Patch cords d. Breakout cables: D. Breakout cables
#54. Which fiber optic connectors do not have a keying device? a. Sub-miniature, typeA b. Biconic c. Straight tip d. Field connector: A. Sub-miniature, typeA
#55. Which of the following is not performed during the system-engineering phase of predeployment? a. Completion of cable cut sheets b. Planning system cannibalization c. Ensuring equipment readiness d. Obtaining necessary frequ: C. Ensuring equipment readiness
#56. When performing equipment checks in the predeployment stage, what frequencies and configurations should you use? a. All possible frequencies and configurations b. The frequencies and configurations spelled out in the frag order: B. The frequencies and configurations spelled out in the frag order
#57*. All of the following is covered in the predeployment briefing except the a. security measures b. local conditions c. purpose of the deployment d. exact duration of the deployment: D. exact duration of the deployment
#58*. The employment phase of a mobility exercise begins when the a. equipment is setup b. first element of the convoy departs c. first element of the convoy arrives at the site d. equipment is operationally ready: B. first element of the convoy departs
#59. The employment phase of a mobility exercise ends when a. the end ex order is received from the governing authority. b. the communications central office releases the equipment. c. the end ex order is received from the users.: a. the end ex order is received from the governing authority.
#60. The first step in recovery at the employment site is to a. conduct a safety briefing b. dismantle, pack, and load the equipment c. dismantle, pack, and load the cantonment area d. request permission to take down the communi: A. conduct a safety briefing
#61*. Into how many Aerospace Expeditionary Forces is the Air Force Total Force divided? a. 6 b. 8 c. 10 d. 12: C. 10
#62*. Aerospace Expeditionary Forces are sized to a. provide a rotation crisis response capability b. tailor forces to the needs of the commander, air force forces c. meet steady-state rotational requirements for forward deployed forces: C. meet steady-state rotational requirements for forward deployed forces
#63*. If assigned to an Air Force Expeditionary Force, how often can you expect to be deployment vulnerable? a. 90 days every 15 months b. 60 days every 15 months c. Alternate 90 day periods d. Alternate 15 months periods: A. 90 days every 15 months
#64*. What is developed for systematic planning of force packages? a. Unit type codes b. Time-phased force and deployment data c. Concepts of operations d. Force modules: A. Unit type codes
#65. What is the unit type code identifier for communications and information? a. 4b b. 3n c. 5c d. 6k: D. 6k
#66*. Name the nerve center for all deployment activity throughout the a.f. a. ECD b. AEFC c. EAFC d. ASETF: B. AEFC
#84. Which of the following records and drawings pertain to broadcast systems equipment only? a. Broadcast facility records b. Broadcast facility model c. Broadcast drawing records indexes d. Broadcast systems installation index: A. Broadcast facility records
#85. What project phase is a good time to try to identify and solve any potential problems? a. Inventory b. Review c. Familiarization d. Docoumentation of review findings: B. Review
#87. Which cabling provides interconnectivity between buildings a. Backbone b. Horizontal c. Segmented d. Maintenance: A. Backbone
#88. The mechanical terminations, patch cords, and jumper cables used to interconnect the media are considered part of which cabling structure? a. maintenance b. segmented c. horizontal d. backbone: C. horizontal
#89. Pairs in multipair cable are twisted to a. minimize crosstalk b. reduce capacitance c. strengthen cables d. allow neatness: A. minimize crosstalk
#90. What is the color code of pair 3 for the horizontal unshielded twisted pair? a. W-bl, bl b. W-o, o c. W-g,g d. W-br, br: C. W-g,g
#91. When placing RG-58 cables the maximum pulling tension allowed is a. 20 pounds b. 25 pounds c. 35 pounds d. 55 pounds: B. 25 pounds
#92. Which of the following distributes the backbone and horizontal fiber optic cables? a. Star/ring b. Ring c. Star d. Bus: C. Star
#93. How many cross-connects are allowed from the main cross-connect to the horizontal interface located in the telecommunications closet? a. 1 b. 2 c. 3 d. 4: B. 2
#94. Single-mode fibers can provide a backbone distance link of up to a. 10 km b. 20 km c. 40 km d. 60 km: D. 60 km
#95. What is used to prevent the direct contact of the securing devices to the cable's outer sheath? a. Vinyl tape. b. Splice wrap. c. Cable shims d. Friction tape: C. Cable shims
#96. A minumum of how many connection ports per work area will all new installations of wall outlets in the local area network distribution system have? a. Six b. Four c. Three d. Two: D. Two
#97. What impact tool is used to terminate the conductors af a CAT-5 cable to on a patch panel? a. D-814 b. H-527 c. 714-b d. 712-a: A. D-814
#98. What do you terminate the conductors of a CAT 5 cable to on a patch panel? a. 110 conductor slots b. 82 termination pins c. 710 connector slots d. 66 connector block: A. 110 conductor slots
#99. The cables used to extend the central office feeder cable to the main cross-connect are marked with what color tags? a. Orange b. White c. Green d. Red: C. Green
#100. What is used to test for direct current resistance? a. Megger b. Ohmmeter c. Vibroground d. Time domain reflectometer: B. Ohmmeter

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