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82 Cards in this Set

  • Front
  • Back
#01*. Modulation enables signals to be transmitted at frequencies
Higher than the original
#02*. What purpose of modulation involves modulating low frequency signals for transmission over long distances?
Ease of radiation
#03. What factor determines the spacing of the sidebands in an amplitude modulated signal?
Frequency of the modulating signal
#04*. The relationship of the bandwidth required for dsbec am to the bandwidth of the modulationg signal of the am bandwidth alone is
twice the modulating bandwidth
#05. what type of device is used to recover the intelligence signal in dsbsc modulation?
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
carrier frequency
#07. What is the relationship of the ssbsc bandwidth comapared to dsbec or dsbsc signals?
SSBSC requires half the bandwidth of the other two
#08. The output of the oscillator in a FM modulator increases in frequency with each
positive half cycle of the modulating signal
#09. In FM, the amount of oscillator frequency change is
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?
#11. How many sidbands does FM produce?
An unlimited number
#12*. In PM, the carriers
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
three times
#14*. What is the first step in the pulse code modulation process?
the analog signal is band limited
#15. Non uniform quantizing and companding decreases the length of the code word from
11 to 7 bits
#16. How fast can an asynchronous transfer mode network potentially move data?
600 mbps
#17*. How does synchronous transmission reduce the overhead costs of data transmission?
Blocks many characters together for transmission
#18*. Which RS-232C signal is the data from the data communications equipment to the data terminal equipment?
Recieve data
#19. Which rs-232c signal indicates the modem is ready to transfer data?
Data set ready
#20. The minimum pins required to establish a two-way data communications path with the RS-232 standard are
Pins 2, 3, and 7
#21. Which standard designates the electrical standards for a balanced voltage digital interface circuit?
#22. What is the transition region voltage in an RS-422 line driver?
-2.0 to +2.0
#23. Which standard uses many of the same pins and functions as RS-232?
#24*. Approximately what percentage of all network problems are cable related according to the National Association of Communications Contractors?
70 percent
#25*. When using vertical redundancy check, what significance does the amount of ones have in a data bit pattern?
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?
Block check character
#27. What two error detection methods, when used together, are 98 percent effective in detecting errors?
Vertical redundancy check and longitudinal redundancy check
#28*. What is the most common error correction technique?
Automatic retransmit on request
#29 When using forward error control as a method of error correction, where does error correction take place?
Receiving end
#30*. Which statement describes an advantage of using fiber optic cable
Electromagnetic fields do not affect fiber optic cables
#31. The designation of one-millionth of meter is
#32*. Most fiber optic links use infrared light that has a frequency range of about
750 to 1500 nm
#33*. What two important facts must be considered when light is propagated through a prism or fiber?
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
angle of indices
#35. Propagation of light as seen by Snells law is known as
total internal reflection
#36*. How is attenuation measured in fiber optics?
Decibels per kilometer
#37*. The two main causes of attenuation in an optic fiber result from absorption and
rayleigh scattering
#38. The most useful way to classify optic fiber cables is by
refractive index profile and number of modes
#39*. In fiber optics a mode can best be described as
the path light travels down fiber
#40. Which classification type of fiber optical cable has the highest dispersion throughout its lenth?
Multimode step-index
#41. A fiber optic cable in which the core has numerous concentric layers of glass is classified as
multimode graded-index
#42. What type of buffer allows the fiber optic cable to be twisted or pulled with little stress on the fiber?
Loose tube
#43*. What outer jacket material used on fiber optic cables has a low resistance to sunlight and abrasion?
Polyvinyl chloride
#44. The basic building block of a breakout cable is known as the
#45. What components make up a complete basic fiber optic link (exclude fiber connections)?
Driver, source optic fiber, detector, and an output circuit
#46. Two types of light sources for fiber optic modems are light-emitting diodes and
semiconductor laser diodes
#47*. What is one of the requirements a light source must have to be beneficial?
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?
#49. What is the PN junction called in a light emitting diode where photons are emanated?
Depletion region
#50. What type of current is produced by a photo detector when no light is present?
#51*. The responsivity of a photodetector is dependent on the
wavelength of light
#52. What photodetector converts one photon to one electron?
Positive intrinsic negative
#53*. Which fiber optic cable configuration consists of multifiber cables?
Breakout cables
#54. Which fiber optic connectors do not have a keying device?
Sub-miniature, typeA
#55. Which of the following is not performed during the system-engineering phase of predeployment?
Ensuring equipment readiness
#56. When performing equipment checks in the predeployment stage, what frequencies and configurations should you use?
The frequencies and configurations spelled out in the frag order
#57*. All of the following is covered in the predeployment briefing except the
exact duration of the deployment
#58*. The employment phase of a mobility exercise begins when the
first element of the convoy departs
#59. The employment phase of a mobility exercise ends when the
the end-ex order is received from the governing authority
#60. The first step in recovery at the employment site is to
conduct a safety briefing
#61*. Into how many Aerospace Expeditionary Forces is the Air Force Total Force divided?
#62*. Aerospace Expeditionary Forces ares sized to
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?
90 days every 15 months
#64*. What is developed for systematic planning of force packages?
Unit type codes
#65. What is the unit type code identifier for communications and information?
#66*. Name the nerve center for all deployment activity thoughout the a.f.
#84. Which of the following records and drawings pertain to broadcast systems equipment only?
Broadcast facility records
#85. What project phase is a good time to try to identify and solve any potential problems?
#87. Which cabling provides interconnectivity between buildings
#88. The mechanical terminations, patch cords, and jumper cables used to interconnect the media are considered part of which cabling structure?
#89. Pairs in multipair cable are twisted to
minimize crosstalk
#90. What is the color code of pair 3 for the horizontal unshielded twisted pair?
#91. When placing RG-58 cables the maximum pullng tension allowed is
25 pounds
#92. Which of the following distributes the backbone and horizontal fiber optic cables?
#93. How many cross-connects are allowed from the main cross-connect to the horizontal interface located in the telecommunications closet?
#94. Single-mode fibers can provide a backbone distance link of up to
60 km
#95. What is used to prevent the direct contact of the securing devices to the cable's outer sheath?
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?
#97. What impact tool is used to terminate the conductors af a CAT-5 cable to on a patch panel?
#98. What do you terminate the conductors of a CAT 5 cable to on a patch panel?
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?
#100. What is used to test for direct current resistance?