• Shuffle
Toggle On
Toggle Off
• Alphabetize
Toggle On
Toggle Off
• Front First
Toggle On
Toggle Off
• Both Sides
Toggle On
Toggle Off
Toggle On
Toggle Off
Front

### How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

Play button

Play button

Progress

1/82

Click to flip

### 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? 3 #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? RS-422 #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? RS-530 #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 Micron #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 subunit #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? Surface #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? Dark #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? 10 #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? 6k #66*. Name the nerve center for all deployment activity thoughout the a.f. AEFC #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? Review #87. Which cabling provides interconnectivity between buildings Backbone #88. The mechanical terminations, patch cords, and jumper cables used to interconnect the media are considered part of which cabling structure? horizontal #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? W-g,g #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? Star #93. How many cross-connects are allowed from the main cross-connect to the horizontal interface located in the telecommunications closet? 2 #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? Two #97. What impact tool is used to terminate the conductors af a CAT-5 cable to on a patch panel? D-814 #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? Green #100. What is used to test for direct current resistance? Ohmmeter