3D152 Volume 1 Ures

69 Questions | Total Attempts: 376

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3D152 Volume 1 Ures

3D152 Volume 1 UREs


Questions and Answers
  • 1. 
    What is an example of analog-to-digital and digital-to-analog techniques?
    • A. 

      Amplitude modulation (AM) and frequency modulation (FM).

    • B. 

      Pulse code modulation (PCM) and frequency shift keying (FSK).

    • C. 

      Phase modulation (PM) and quadrature phase shift keying (QPSK).

    • D. 

      Pulse code modulation (PCM) and continuously variable slope delta (CVSD) modulation.

  • 2. 
    What converts analog signal information into an analog carrier signal?
    • A. 

      Delta modulation (DM).

    • B. 

      Digital modulation.

    • C. 

      Analog modulation.

    • D. 

      Adaptive modulation.

  • 3. 
    What converts analog signal information into a digital carrier signal?
    • A. 

      Delta modulation (DM).

    • B. 

      Analog modulation.

    • C. 

      Digital modulation.

    • D. 

      Adaptive modulation.

  • 4. 
    The information-carrying components that occur on either side of a carrier are called
    • A. 

      Sidebands.

    • B. 

      Sine waves.

    • C. 

      Frequency translators.

    • D. 

      Modulating frequencies.

  • 5. 
    Amplitude modulation (AM) requires a bandwidth that is
    • A. 

      Twice that of the modulating signal.

    • B. 

      Half that of the modulating signal.

    • C. 

      Twice that of the carrier signal.

    • D. 

      Half that of the carrier signal.

  • 6. 
    The upper sideband in a single-sideband suppressed carrier (SSBSC) modulation is eliminated by
    • A. 

      Filtering.

    • B. 

      Detection.

    • C. 

      Compression.

    • D. 

      Companding.

  • 7. 
    We can express the 6-to–1 improvement of the single-sideband suppressed carrier (SSBSC) modulation over conventional amplitude modulation (AM) as
    • A. 

      2 decibels (dB) of improvement.

    • B. 

      4 dB of improvement.

    • C. 

      6 dB of improvement.

    • D. 

      8 dB of improvement.

  • 8. 
    The only basic waveform in nature is a
    • A. 

      Carrier wave.

    • B. 

      Pure sine wave.

    • C. 

      Resultant wave.

    • D. 

      Composite wave.

  • 9. 
    A modulated waveform that contains a carrier plus two sidebands for each modulation frequency is a description of
    • A. 

      A phase modulation (PM).

    • B. 

      A pulse modulation.

    • C. 

      A frequency modulation (FM).

    • D. 

      An amplitude modulation (AM).

  • 10. 
    The amount of deviation in a frequency modulation (FM) signal is directly proportional to the modulating signal’s
    • A. 

      Phase.

    • B. 

      Amplitude.

    • C. 

      Frequency.

    • D. 

      Amplitude and frequency.

  • 11. 
    If 100 percent modulation is exceeded and there is distortion in the modulating signal, additional sidebands are generated. We identify these sidebands as what?
    • A. 

      Transmitted intelligence.

    • B. 

      Intensity of speech.

    • C. 

      Composite waves.

    • D. 

      Splatter.

  • 12. 
    What is the main advantage of differential phase shift keying (DPSK)?
    • A. 

      Carrier presence is required to detect changes.

    • B. 

      It requires a less complex receiver than a basic phase shift keying (PSK) signal.

    • C. 

      It requires a more complex receiver than a basic PSK signal.

    • D. 

      The demodulator needs to detect changes in absolute phase values.

  • 13. 
    Which of the following is not considered an analog modulation techniques?
    • A. 

      Pulse-amplitude modulation (PAM).

    • B. 

      Pulse-duration modulation (PDM).

    • C. 

      Pulse-position modulation (PPM).

    • D. 

      Pulse-code modulation (PCM).

  • 14. 
    The amount of phase shift in a phase modulation (PM) signal is directly proportional to the
    • A. 

      Modulation index.

    • B. 

      Rate of phase shift.

    • C. 

      Frequency of the modulating signal.

    • D. 

      Amplitude of the modulating signal.

  • 15. 
    What form of modulation is insensitive to signal variations?
    • A. 

      Delta.

    • B. 

      Frequency shift keying (FSK).

    • C. 

      Pulse-amplitude modulation (PAM).

    • D. 

      Binary-phase shift keying or bi-phase shift keying (BPSK).

  • 16. 
    In quadrature-phase shift keying (QPSK) the radio frequency (RF) bandwidth for a quadriphase signal is what of that required by a bi-phase signal, given the same data rate.
    • A. 

      Four times.

    • B. 

      Double.

    • C. 

      Half.

    • D. 

      The same.

  • 17. 
    The form of pulse modulation in which the pulse is varied within a set range of positions is known as
    • A. 

      Pulse-amplitude modulation (PAM).

    • B. 

      Pulse-duration modulation (PDM).

    • C. 

      Pulse-position modulation (PPM).

    • D. 

      Pulse-code modulation (PCM).

  • 18. 
    Quantized analog modulation is actually
    • A. 

      Pulse-amplitude modulation (PAM).

    • B. 

      Pulse-duration modulation (PDM).

    • C. 

      Less tolerant of noise than frequency modulation (FM).

    • D. 

      Analog-to-digital conversion.

  • 19. 
    How many bits per character of a 16-step pulse-code modulation (PCM) system are used to describe the quantized analog sample?
    • A. 

      3.

    • B. 

      4.

    • C. 

      5.

    • D. 

      8.

  • 20. 
    The process of coding pulse code modulation (PCM) quantized pulses to make them a constant duration and amplitude is
    • A. 

      Encoding.

    • B. 

      Companding.

    • C. 

      Uniform quantizing.

    • D. 

      Nonuniform quantizing.

  • 21. 
    In Time Division Multiplexing (TDM), the transmitting multiplexer will put a bit or a byte from each of the incoming lines into a specifically allocated what?
    • A. 

      Channel.

    • B. 

      Trunk.

    • C. 

      Time slot.

    • D. 

      Port.

  • 22. 
    The two major types of frame structures are
    • A. 

      Low speed and high speed.

    • B. 

      High speed and EBCDIC.

    • C. 

      CCITT and low speed.

    • D. 

      EBCDIC and CCITT.

  • 23. 
    The method of multiplexing the T1 multiplexer uses is
    • A. 

      Frequency division.

    • B. 

      Binary division.

    • C. 

      Pulse division.

    • D. 

      Time division.

  • 24. 
    Wave-division multiplexing (WDM) creates the virtual channels for multiplexing them together for transmission by using different
    • A. 

      Wavelengths or lambdas.

    • B. 

      Wavelengths or gammas.

    • C. 

      Frequencies or lambdas.

    • D. 

      Frequencies or gammas.

  • 25. 
    The most common wave-division multiplexing (WDM) system uses how many wavelengths?
    • A. 

      One wavelength.

    • B. 

      Two wavelengths.

    • C. 

      Three wavelengths.

    • D. 

      Four wavelengths.

  • 26. 
    Individual pulses within a digital signal are
    • A. 

      Bits.

    • B. 

      Bytes.

    • C. 

      Codes.

    • D. 

      Blocks.

  • 27. 
    What unit is most commonly used in data systems to express signaling speed?
    • A. 

      Baud.

    • B. 

      Baudot.

    • C. 

      Sense interface.

    • D. 

      Bits per second.

  • 28. 
    Bit count integrity problems are primarily caused by
    • A. 

      Impedance mismatch.

    • B. 

      System timing faults.

    • C. 

      Improper equipment settings.

    • D. 

      Changes in atmospheric conditions.

  • 29. 
    Three categories of synchronization used in digital data circuits are
    • A. 

      Synchronous, asynchronous, and isochronous.

    • B. 

      Isochronous, asynchronous, and bisynchronous.

    • C. 

      Nonsynchronous, bisynchronous, and synchronous.

    • D. 

      Asynchronous, bisynchronous, and nonsynchronous.

  • 30. 
    Which option is a characteristic of synchronous data operation?
    • A. 

      Timing pulses are transmitted within the signal stream.

    • B. 

      Start and stop pulses control data transmission.

    • C. 

      System timing is not of critical importance.

    • D. 

      All data bits are the same length in time.

  • 31. 
    A digital signal that contains synchronizing bits within the signal stream describes
    • A. 

      Synchronous operation.

    • B. 

      Asynchronous operation.

    • C. 

      Synchronous and/or isochronous operation.

    • D. 

      Asynchronous and/or synchronous operation.

  • 32. 
    In what type of signal is the information contained in the transition, and there is a transition from one state to the other only when a mark bit is sent?
    • A. 

      Non-return-to-zero (NRZ) level.

    • B. 

      Non-return-to-zero mark.

    • C. 

      Non-return-to-zero space.

    • D. 

      Return-to-zero level.

  • 33. 
    In what type of signal does the signal level move to one of the discrete signal levels, but returns to the zero level after a predetermined time?
    • A. 

      Non-return-to-zero (NRZ) level.

    • B. 

      Non-return-to-zero mark.

    • C. 

      Non-return-to-zero space.

    • D. 

      Return-to-zero.

  • 34. 
    Which statement best describes an alternate mark inversion (AMI) signal?
    • A. 

      The information is transmitted in three different voltage levels.

    • B. 

      A logic one is transmitted as positive voltage if the previous logic one was negative.

    • C. 

      The level always returns to zero for 50 percent of the bit cycle after every transition.

    • D. 

      Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros.

  • 35. 
    Digital coding techniques such as binary with eight-zero substitution (B8ZS) are becoming more popular because they are designed to
    • A. 

      Provide error-free signaling.

    • B. 

      Operate at higher data rates.

    • C. 

      Eliminate bipolar violations.

    • D. 

      Maintain ones density standards.

  • 36. 
    Which statement best describes a binary with eight-zero substitution (B8ZS) signal?
    • A. 

      The information is transmitted in three different voltage levels.

    • B. 

      A logic one is transmitted as positive voltage if the previous logic one was negative.

    • C. 

      The level always returns to zero for 50 percent of the bit cycle after every transition.

    • D. 

      Bipolar violations are intentionally inserted into a data signal to break up long strings of zeros.

  • 37. 
    The major difference between conditioned di-phase (CDI) and other schemes is the
    • A. 

      Lack of mid-bit transitions.

    • B. 

      Use of mid-bit transitions for timing.

    • C. 

      Data being encoded in the mid-bit transitions.

    • D. 

      Voltage levels used for signaling the mid-bit transitions.

  • 38. 
    How many bits are in the D4 framing sequence?
    • A. 

      8.

    • B. 

      12.

    • C. 

      24.

    • D. 

      48.

  • 39. 
    How many bits are in the extended superframe format (ESF) framing sequence?
    • A. 

      8.

    • B. 

      12.

    • C. 

      24.

    • D. 

      48.

  • 40. 
    What communications control signal uses a two-frequency dialing combination?
    • A. 

      Pulse dialing.

    • B. 

      Tone dialing.

    • C. 

      Digit dialing.

    • D. 

      Address dialing.

  • 41. 
    What communications information signal uses a continuous 350- and 440-Hz frequency pair?
    • A. 

      Dial tone.

    • B. 

      Ringback signal.

    • C. 

      Off-hook alert.

    • D. 

      Call waiting.

  • 42. 
    What communications information signal uses a signal cycled on and off for 0.5 second and contains the generation of a 480- and 620-Hz frequency pair?
    • A. 

      Dial tone.

    • B. 

      Busy signal.

    • C. 

      Off-hook alert.

    • D. 

      Call waiting.

  • 43. 
    What communications supervisory signal uses a continuous application of direct current voltage for signaling?
    • A. 

      Record warning.

    • B. 

      Fast busy signal.

    • C. 

      Loop-start.

    • D. 

      E and M.

  • 44. 
    When is the voltage applied in loop-start signaling?
    • A. 

      When dial tone is present.

    • B. 

      On-hook condition.

    • C. 

      Off-hook condition.

    • D. 

      During the ringback signal.

  • 45. 
    In common associated signaling (CAS), what is the seventh bit in frames 6 and 12 used to convey signaling information known as?
    • A. 

      Bit robbing.

    • B. 

      Bit stuffing.

    • C. 

      Frame correction.

    • D. 

      Frame enhancement.

  • 46. 
    In what common channel signaling (CCS) mode are the messages relating to signaling between two points conveyed directly interconnecting these signaling points?
    • A. 

      Associated mode.

    • B. 

      Nonassociated mode.

    • C. 

      Quasi-associated mode.

    • D. 

      Multi-associated mode.

  • 47. 
    What are the two principle weighting characteristics in use with telecommunication circuit noise?
    • A. 

      Institute of Electronic and Electrical Engineers and CCITT psophometric.

    • B. 

      Noise analysis and CCITT psophometric.

    • C. 

      CCITT psophometric and C-message.

    • D. 

      C-message and noise analysis.

  • 48. 
    While timing makes sure the equipment is sending and receiving bits at the same time intervals, synchronization makes sure that the
    • A. 

      Receive equipment timing is set properly.

    • B. 

      Transmit equipment timing is set properly.

    • C. 

      Receive equipment can find its place in the bit stream.

    • D. 

      Transmit equipment can find its place in the bit stream.

  • 49. 
    What term is associated with the delay or lag introduced in the application of voltage from one section to the next?
    • A. 

      Latency.

    • B. 

      Phase delay.

    • C. 

      Propagation constant.

    • D. 

      Phase delay distortion.

  • 50. 
    Attenuation distortion is caused by
    • A. 

      A line loss for the various frequency components comprising a voice transmission.

    • B. 

      The line loss, the distance of transmission lines, and faults in the transmission cables.

    • C. 

      Faults in the transmission cables and the number of splices in the line varying with the frequency.

    • D. 

      Differing attenuation rates for the various frequency components comprising a voice frequency transmission.

  • 51. 
    Jamming a portion of the frequency spectrum is an example of
    • A. 

      Electronic combat.

    • B. 

      Electronic protection.

    • C. 

      Electronic attack.

    • D. 

      Electronic warfare support.

  • 52. 
    The definition of electronic attack can be found in which publication?
    • A. 

      Air Force Doctrine Document 2–5.1.

    • B. 

      Air Force Instruction 10–101.

    • C. 

      Air Force Policy Memorandum 2–1.

    • D. 

      Air Force Manual 2–5.1.

  • 53. 
    Any actions we take to protect our forces, facilities, and equipment for electronic action that can destroy or degrade our capabilities is considered
    • A. 

      Electronic combat.

    • B. 

      Electronic protection.

    • C. 

      Electronic attack.

    • D. 

      Electronic warfare support.

  • 54. 
    Varying the pulse repetition frequency on a radar set is an example of
    • A. 

      Electronic combat.

    • B. 

      Electronic attack.

    • C. 

      Electronic protection.

    • D. 

      Electronic warfare support.

  • 55. 
    Electronic warfare support includes devices such as
    • A. 

      Anti-radiation missiles and directed energy weapons.

    • B. 

      Intelligence platforms and noise jamming systems.

    • C. 

      Radar warning receivers and intelligence systems.

    • D. 

      Directed energy weapons and radar warning receivers.

  • 56. 
    When a multimeter has three input terminal jacks, which jack is always used?
    • A. 

      Voltage terminal.

    • B. 

      Common terminal.

    • C. 

      Voltage and current terminal.

    • D. 

      Common and current terminal.

  • 57. 
    When using a multimeter, which mode should be used if the reading is unreadable due to fluctuations?
    • A. 

      Range.

    • B. 

      Frequency.

    • C. 

      Display hold.

    • D. 

      Minimum/maximum (MIN/MAX).

  • 58. 
    When using a multimeter, which mode should be used if the reading fluctuates and a more accurate reading is desired?
    • A. 

      Minimum/maximum (MIN/MAX).

    • B. 

      Display hold.

    • C. 

      Frequency.

    • D. 

      Range.

  • 59. 
    When using an ohmmeter to take a resistance reading, what preliminary precaution should you take?
    • A. 

      Properly seat the test lead into the current input terminal jack.

    • B. 

      Disconnect the power from the circuit being tested.

    • C. 

      Place the meter in the frequency mode.

    • D. 

      Set the range for maximum reading.

  • 60. 
    What principle of operation does the time domain reflectometer use to test cables?
    • A. 

      Amplitude.

    • B. 

      Frequency.

    • C. 

      Audio.

    • D. 

      Radar.

  • 61. 
    Which push-buttons would you select to get 125-ohm (Ω) impedance on the time domain reflectometer?
    • A. 

      50Ω, 75Ω, and 125Ω.

    • B. 

      75Ω and 125Ω.

    • C. 

      50Ω and 125Ω.

    • D. 

      50Ω and 75Ω.

  • 62. 
    What is the power that is reflected back to an optical source in the time domain reflectometer (TDR)?
    • A. 

      Reflection.

    • B. 

      Backscatter.

    • C. 

      Scatter coefficient.

    • D. 

      Reflection coefficient.

  • 63. 
    What are the two major sections of a bit error rate test (BERT) set?
    • A. 

      Emitter and detector.

    • B. 

      Emitter and receiver.

    • C. 

      Transmitter and detector generator.

    • D. 

      Transmitter and receiver.

  • 64. 
    Which section of a bit error rate test (BERT) set measures the received test pattern?
    • A. 

      Transmitter.

    • B. 

      Emitter.

    • C. 

      Detector.

    • D. 

      Receiver.

  • 65. 
    What type of framing format should you use to conduct a bit error rate test (BERT) on a T1 circuit configured for binary with eight-zero substitution (B8ZS) coding?
    • A. 

      Extended superframe.

    • B. 

      Alternate mark inversion.

    • C. 

      Return-to-zero.

    • D. 

      Superframe.

  • 66. 
    When performing a bit error rate test (BERT), what determines the size of a test pattern segment?
    • A. 

      The total number of bits in the test pattern.

    • B. 

      The total number of bytes that represent the bits test pattern.

    • C. 

      The number of bits that can represent the total number of bits in the test pattern.

    • D. 

      The number of bits in the number of bytes that are equally divided into the test pattern.

  • 67. 
    What type of error is the result of two successive logic one pulses of the same polarity in violation of alternate mark inversion coding rules?
    • A. 

      Cyclic redundancy check.

    • B. 

      Bipolar violation.

    • C. 

      Bit slip.

    • D. 

      Frame.

  • 68. 
    On a breakout box, how many RS–232 key interface signals can be monitored and accessed individually?
    • A. 

      12.

    • B. 

      20.

    • C. 

      24.

    • D. 

      25.

  • 69. 
    The purpose of the miniature ON/OFF switches on a breakout box is to
    • A. 

      Measure the individual interface signals.

    • B. 

      Change the voltage of individual interface signals.

    • C. 

      Allow the interruption of the individual interface conductors.

    • D. 

      Allow the cross-patching of the individual interface conductors.