Z3d153 Volume 2 Ure (2019)

100 Questions

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Z3d153 Volume 2 Ure (2019)

All answers as of 3/25/2019 have been checked by a bunch of radio nerds, and are correct.


Questions and Answers
  • 1. 
    Which US government agency divides the radio frequency spectrum into different bands?
    • A. 

      Federal Aviation Agency.

    • B. 

      American National Standard Institute.

    • C. 

      Federal Communications Commission (FCC).

    • D. 

      Institute of Electrical & Electronics Engineers, Inc.

  • 2. 
    High-frequency (HF) transmissions are normally conducted in which two operating modes?
    • A. 

      Frequency modulation (FM) and independent sidebands (ISB).

    • B. 

      Continuous wave (CW) and amplitude modulation (AM).

    • C. 

      Single side band (SSB) and FM.

    • D. 

      SSB and ISB.

  • 3. 
    Which frequency band is most susceptible to jamming?
    • A. 

      Low frequency (LF)

    • B. 

      Medium frequency (MF).

    • C. 

      High frequency (HF).

    • D. 

      Very high frequency (VHF).

  • 4. 
    The ability of a receiver to reproduce the signal of a very weak station is characteristic of a receiver’s
    • A. 

      Fidelity.

    • B. 

      Capacity.

    • C. 

      Sensitivity

    • D. 

      Selectivity.

  • 5. 
    The ability of a receiver to reproduce the input signal accurately is characteristic of its
    • A. 

      Fidelity

    • B. 

      Capacity

    • C. 

      Sensitivity.

    • D. 

      Selectivity

  • 6. 
    A combination transmitter and receiver, built as a single unit and shares common tuned circuits, is called a
    • A. 

      Transmitter.

    • B. 

      Transceiver.

    • C. 

      Receiver

    • D. 

      Coupler.

  • 7. 
    Conductor material resistance in a transmission line leads to this type of loss.
    • A. 

      Copper.

    • B. 

      Radiation

    • C. 

      Inductive

    • D. 

      Skin-effect

  • 8. 
    The amount of skin-effect loss is directly proportional to the
    • A. 

      Line length

    • B. 

      Frequency

    • C. 

      Voltage level

    • D. 

      Resistive loss

  • 9. 
     Leakage loss in a transmission line is minimized by using a
    • A. 

      Thinner conductor

    • B. 

      thicker conductor

    • C. 

      Very low-resistance dielectric

    • D. 

      Very high-resistance dielectric.

  • 10. 
    A transmission line that consists of a center conductor, placed inside a rigid metal tube that functions as the outer shield, is called 
    • A. 

      Flexible coaxial cable.

    • B. 

      Rigid coaxial cable.

    • C. 

      Waveguide

    • D. 

      Twin lead

  • 11. 
    A waveguide is a type of transmission line that you would use 
    • A. 

      When the frequencies are so high that their wavelength is miniscule.

    • B. 

      to transmit on frequencies too low for ground propagation.

    • C. 

      for high power at frequencies up to 30 megahertz (MHz) primarily.

    • D. 

      To receive television frequencies over the air.

  • 12. 
    All statements concerning waveguides are true except
    • A. 

      Their outer surface will arc from being very slightly damaged.

    • B. 

      Their conductive material construction is easily dented.

    • C. 

      Their effectiveness is hindered by moisture.

    • D. 

      They can be destroyed by corrosion.

  • 13. 
    Which two transmission line properties determine its characteristic impedance (ZO)?
    • A. 

      Inductance and resistance.

    • B. 

      Inductance and capacitance

    • C. 

      Resistance and capacitance.

    • D. 

      Length and type of shielding.

  • 14. 
    This is the correct statement concerning a wavelength.
    • A. 

      Wavelength is inversely related to frequency.

    • B. 

      Wavelength is directly related to frequency.

    • C. 

      Wavelength is determined by the line length.

    • D. 

      Wavelength is expressed in lambdas (λ).

  • 15. 
    Determine the wavelength of a 250 megahertz (MHz) signal.
    • A. 

      12.0 meters

    • B. 

      3.0 meters

    • C. 

      1.5 meters

    • D. 

      1.2 meters

  • 16. 
    A nonresonant transmission line is one with
    • A. 

      Reflected waves

    • B. 

      No reflected waves

    • C. 

      Maximum voltage across its open termination.

    • D. 

      Maximum voltage across its shorted termination.

  • 17. 
    When discussing resonant and nonresonant transmission lines,
    • A. 

      Resonant lines are often referred to as flat lines

    • B. 

      Maximum power transfer results from a resonant line

    • C. 

      Maximum power transfer results from a nonresonant line

    • D. 

      Significant loss and damage to equipment results from using a nonresonant line.

  • 18. 
    This will likely result if a transmission line is terminated in an open.
    • A. 

      Signal loss would be negligible.

    • B. 

      Signal loss would be significant.

    • C. 

      Current would be maximum at the termination.

    • D. 

      Voltage would be minimum at the termination

  • 19. 
    Direct waves are radio waves that travel
    • A. 

      Long distances with few interruptions.

    • B. 

      From point to point along the Earth’s surface.

    • C. 

      No more than 20 miles to the receive antenna

    • D. 

      Through the air in a straight line from transmitter to receiver

  • 20. 
    Radio waves that travel near the Earth’s surface are called
    • A. 

      Earth waves

    • B. 

      Global waves

    • C. 

      Ground waves

    • D. 

      Terrestrial waves

  • 21. 
    The Earth’s conductivity is determined by the type of
    • A. 

      Atmospheric conditions at the time of transmission.

    • B. 

      Air and moisture content in the propagation path.

    • C. 

      Soil and water in the propagation path.

    • D. 

      soil and air in the propagation path

  • 22. 
    This term is used to describe radio waves that bend as they travel from one medium to another that has different density
    • A. 

      Diffusion

    • B. 

      Diffraction

    • C. 

      Refraction

    • D. 

      Reflection

  • 23. 
    The refractive index of air depends on moisture
    • A. 

      Atmospheric pressure, and temperature.

    • B. 

      atmospheric pressure, and frequency.

    • C. 

      Receive signal level, and temperature

    • D. 

      Receive signal level, and frequency.

  • 24. 
    When comparing the radio and optical horizons, which one is farther away and by what percentage?
    • A. 

      Optical; 15

    • B. 

      Radio; 15.

    • C. 

      Optical; 33.

    • D. 

      Radio; 33

  • 25. 
    Which process permits communication in shadow regions behind obstacles?
    • A. 

      Reflection

    • B. 

      Scattering

    • C. 

      Refraction

    • D. 

      Diffraction

  • 26. 
    Which frequency range will show little effect from precipitation?
    • A. 

      HF

    • B. 

      UHF

    • C. 

      SHF

    • D. 

      EHF

  • 27. 
     Line-of-sight (LOS) radio waves that are guided through the air between two layers of the atmosphere are known as
    • A. 

      Channeling

    • B. 

      Guiding

    • C. 

      Ducting

    • D. 

      Piping

  • 28. 
    Which condition gives sky-wave propagation its ability to communicate beyond the optical line-of-sight (LOS)?
    • A. 

      Refraction

    • B. 

      Reflection

    • C. 

      Earth’s conductivity

    • D. 

      Atmospheric charge.

  • 29. 
    The angle at which a radio wave enters the ionosphere is known as the
    • A. 

      Skip angle

    • B. 

      Critical angle

    • C. 

      Angle of entrance

    • D. 

      Angle of incidence

  • 30. 
    There are several critical sky-wave propagation angles and frequencies. Radio waves that angle too low are
    • A. 

      Refracted

    • B. 

      Returned to Earth

    • C. 

      Absorbed before refraction occurs

    • D. 

      Passed through the ionosphere into space

  • 31. 
    In sky-wave propagation, frequencies higher than the critical frequency are
    • A. 

      Returned to Earth

    • B. 

      Passed into space

    • C. 

      The most desirable

    • D. 

      Refracted by the F2 player

  • 32. 
    The term frequency of optimum transmission (FOT) is also referred to as the
    • A. 

      Outbound traffic frequency

    • B. 

      Optimum tropospheric frequency

    • C. 

      Optimum traffic frequency.

    • D. 

      Frequency of outbound transmission.

  • 33. 
    In sky- and ground-wave propagation, the area of silence where no signals are received is known as the
    • A. 

      Propagation distance

    • B. 

      Skip distance

    • C. 

      Dead zone

    • D. 

      Skip zone

  • 34. 
    This occurs when a transmitted signal travels over two or more separate paths during transmission
    • A. 

      Skip effects

    • B. 

      Modulation

    • C. 

      Multipathing

    • D. 

      Magneton splitting

  • 35. 
    How many layers make up the Earth’s atmosphere?
    • A. 

      2

    • B. 

      3

    • C. 

      4

    • D. 

      5

  • 36. 
    This occurs when high-energy ultraviolet light waves from the sun enter the ionospheric region of the atmosphere and strike the gas atoms.
    • A. 

      Ionization

    • B. 

      Modulation

    • C. 

      Conductivity

    • D. 

      Recombination

  • 37. 
    The atmospheric recombination process is dependent on the
    • A. 

      Season

    • B. 

      Time of day (TOD)

    • C. 

      Regular variation

    • D. 

      Irregular variations

  • 38. 
    Which layer of the ionosphere is most important for high-frequency (HF) communications?
    • A. 

      D

    • B. 

      E

    • C. 

      F

    • D. 

      Topside

  • 39. 
    During which season do we have the wider range of critical frequencies and less absorption of all frequencies?
    • A. 

      Fall

    • B. 

      Winter

    • C. 

      Spring

    • D. 

      Summer

  • 40. 
    As ionospheric solar variations, sunspots are disturbances that appear and disappear
    • A. 

      In the sun’s atmosphere

    • B. 

      On the sun’s surface.

    • C. 

      In the ionosphere.

    • D. 

      Beneath the sun’s surface.

  • 41. 
    On which regular ionospheric variation do sunspots occur?
    • A. 

      11-day cycle

    • B. 

      11-week cycle

    • C. 

      11-month cycle

    • D. 

      11-year cycle.

  • 42. 
     In a basic communication system, this is used to convert radio frequency (RF) current oscillation into electric and magnetic fields of force.
    • A. 

      Antenna

    • B. 

      Transmitter

    • C. 

      Coupler

    • D. 

      Transmission lines

  • 43. 
    The concept where alternating current (AC) changes in magnitude, and reverses its direction during each cycle, is
    • A. 

      An unproven hypothesis.

    • B. 

      The definition of propagation

    • C. 

      What makes radio transmission possible.

    • D. 

      What led to the discovery of direct current (DC).

  • 44. 
    At which point do magnetic fields around a wire no longer have time to collapse completely between alternations?
    • A. 

      60 cycles per second (cps).

    • B. 

      120 cps.

    • C. 

      10,000 cps.

    • D. 

      15,000 cps

  • 45. 
    In radio-wave creation, which type of field detaches from the antenna and travels through space at great distances?
    • A. 

      Radiation

    • B. 

      Induction

    • C. 

      Gravitational

    • D. 

      Electromotive

  • 46. 
    Which types of polarization do most satellite communication terminals transmit and receive?
    • A. 

      Transmit horizontal and receive vertical polarizations

    • B. 

      Transmit vertical and receive horizontal polarizations.

    • C. 

      Transmit right-hand circular and receive left-hand circular polarizations.

    • D. 

      Transmit left-hand circular and receive right-hand circular polarizations

  • 47. 
    A resonant antenna effectively radiates a radio signal for frequencies close to its designed frequency. Which percentage range, plus or minus, is it usually within?
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      4

  • 48. 
    The design frequency of a resonant antenna is 10 megahertz (MHz). What will be its frequency range?
    • A. 

      8–10 MHz.

    • B. 

      9–11 MHz

    • C. 

      9.5–10.5 MHz

    • D. 

      9.8–10.2 MHz.

  • 49. 
    The lowest frequency at which an antenna resonates is known as its
    • A. 

      Standing wave

    • B. 

      Fundamental

    • C. 

      Resonation

    • D. 

      Primary

  • 50. 
    The ability of an antenna to both receive and transmit equally well is known as the antenna’s
    • A. 

      Bandwidth

    • B. 

      Resonance

    • C. 

      Reciprocity

    • D. 

      Effectiveness

  • 51. 
    This matching device is inserted to make a transmitter “think” it is connected to a low standing-wave ratio (SWR) antenna.
    • A. 

      Stub

    • B. 

      Balun

    • C. 

      Coupler

    • D. 

      Terminating resistor

  • 52. 
    This matching device would be used to connect a 52-ohms RG–213 cable to an antenna with an impedance of 600-ohms.
    • A. 

      Balun

    • B. 

      Coupler

    • C. 

      Reflector

    • D. 

      Terminating resistor

  • 53. 
    Which type of antenna radiates radio energy equally well in all directions?
    • A. 

      Omni-directional.

    • B. 

      Uni-directional.

    • C. 

      Bi-directional.

    • D. 

      Directional

  • 54. 
    Add this device to make a long-wire antenna more directional.
    • A. 

      Stub

    • B. 

      Balun

    • C. 

      Coupler

    • D. 

      Terminating resistor

  • 55. 
    Beam width of a directive antenna is measured at the
    • A. 

      Quarter-power point.

    • B. 

      Half-power point.

    • C. 

      Three-quarters power point

    • D. 

      Maximum value point.

  • 56. 
    A dipole or long-wire antenna is an example of a
    • A. 

      Whip antenna.

    • B. 

      Hertz antenna.

    • C. 

      Marconi antenna.

    • D. 

      Vertical monopole.

  • 57. 
    This is one of the simplest and most functional antennas in use
    • A. 

      Quarter-wave vertical.

    • B. 

      Half-wave dipole.

    • C. 

      Inverted-V.

    • D. 

      GRA–4.

  • 58. 
    The minimum length of a long-wire antenna is
    • A. 

      One-quarter wavelength.

    • B. 

      One-half wavelength.

    • C. 

      One wavelength.

    • D. 

      Two wavelengths.

  • 59. 
    You should use this type of antenna to communicate over the horizon to an amphibious ship on the move or to a station up to 450 kilometers away.
    • A. 

      Near-vertical incidence sky-wave.

    • B. 

      Helical.

    • C. 

      Inverted-V.

    • D. 

      Inverted-L

  • 60. 
    How are most antennas designed that are used in satellite communications?
    • A. 

      Circular-directional.

    • B. 

      Omni-directional.

    • C. 

      Bi-directional.

    • D. 

      Directional.

  • 61. 
    Which type of polarization is used to radiate a signal using a helical satellite antenna?
    • A. 

      Horizontal

    • B. 

      Vertical

    • C. 

      Circular

    • D. 

      Linear

  • 62. 
    This type of antenna is used to transmit and receive microwave signals
    • A. 

      Horn

    • B. 

      Whip

    • C. 

      Helical

    • D. 

      Log-periodic

  • 63. 
    Where are aircraft antennas normally housed?
    • A. 

      Inside nonconductive radomes outside or flush with the fuselage.

    • B. 

      Inside conductive radomes outside or flush with the fuselage.

    • C. 

      Outside nonconductive radomes outside the fuselage.

    • D. 

      Inside conductive radomes flush with the fuselage.

  • 64. 
    At which vertical angles should the multi-hop, long-distance transmission be used in airborne antenna applications for frequencies in the upper portion of the high-frequency (HF) band?
    • A. 

      90 and 180 degrees.

    • B. 

      60 and 90 degrees.

    • C. 

      30 and 60 degrees

    • D. 

      5 and 30 degrees.

  • 65. 
    This is the best way to orient line-of-sight (LOS) antennas.
    • A. 

      Toward the true north bearing.

    • B. 

      Away from the receiving station.

    • C. 

      Away from the magnetic north bearing.

    • D. 

      In a straight path to the receiving station.

  • 66. 
    When siting a radio station, which type of foliage would have a more adverse effect on radio-wave propagation?
    • A. 

      Broadleaf trees

    • B. 

      Evergreen trees

    • C. 

      Swamp grass

    • D. 

      Sagebrush

  • 67. 
    This has the greatest effect on an antenna’s radiation pattern.
    • A. 

      Sun

    • B. 

      Earth

    • C. 

      Operator

    • D. 

      Ionosphere

  • 68. 
    This is one fundamental rule about camouflage.
    • A. 

      Sawed-off branches and foliage should not be used.

    • B. 

      Site should be visualized from above

    • C. 

      Equipment should be widely separated.

    • D. 

      Straight lines are obvious.

  • 69. 
    This is the most effective type of antennas in mountainous terrain that has a mountain between you and the distant end.
    • A. 

      Whip

    • B. 

      Dipole

    • C. 

      Discone

    • D. 

      Near-vertical incidence sky-wave

  • 70. 
    Which electronic warfare (EW) component responds to a tasking to search for, intercept, identify, and locate intentional and unintentional sources of radiated energy?
    • A. 

      Attack

    • B. 

      Control

    • C. 

      Support

    • D. 

      Protection

  • 71. 
    Electromagnetic (EM) deception, as it applies to electronic warfare (EW), is
    • A. 

      Controlling the information an enemy receives.

    • B. 

      Eliminating some, or all, of an adversary’s electronic defenses.

    • C. 

      Conveying misleading information to an enemy through the deliberate radiation of EM energy.

    • D. 

      Degrading, or interfering with, the enemy’s use of the EM spectrum to limit an enemy’s combat capabilities

  • 72. 
    In frequency-hopping (FH) operations, the interval at which each transmitter remains on a given frequency for a specific time is known as
    • A. 

      Dwell time

    • B. 

      Hopping rate

    • C. 

      Frequency offset

    • D. 

      Transmitter velocity

  • 73. 
    Which type of hopping-rate category changes frequencies approximately 100 times per second?
    • A. 

      Slow

    • B. 

      Medium

    • C. 

      Fast

    • D. 

      Conference

  • 74. 
    What does the term “ICOM” indicate?
    • A. 

      Internal call-out module

    • B. 

      Intelligent communications.

    • C. 

      Integrated communications

    • D. 

      Integrated communications security.

  • 75. 
    Which statement best identifies the requirements for two transceivers to establish HAVE QUICK (HQ) communications?
    • A. 

      They must be the same model number

    • B. 

      They must be the same version of transceiver.

    • C. 

      They must be use the same encryption variables.

    • D. 

      They must have the same word of day (WOD) and time of day (TOD).

  • 76. 
    How long is each word-of-day (WOD) used with the HAVE QUICK II (HQII) communications multiple word-of-day (MWOD)?
    • A. 

      Until manually changed

    • B. 

      3 days

    • C. 

      48 hours

    • D. 

      24 hours

  • 77. 
    Which tactical data link (TDL) is a secure, full-duplex, point-to-point digital data link that uses satellite, microwave, or terrestrial cable, as opposed to a modulated waveform, to transmit data?
    • A. 

      Link 4

    • B. 

      Link 11

    • C. 

      Link 11b

    • D. 

      Link 16

  • 78. 
    Which multiple channel access method eliminates the requirement for a net control station (NCS) in the joint tactical information distribution system (JTIDS) by providing node-less communications network architecture?
    • A. 

      Code division

    • B. 

      Time division

    • C. 

      Space division

    • D. 

      Frequency division

  • 79. 
    The Air Force integrates with modified close air support aircraft with digitized battlefield information using this type of network.
    • A. 

      Single channel (SC) ground and airborne radio system.

    • B. 

      Enhanced position location reporting system (EPLRS).

    • C. 

      Joint tactical information distribution system (JTIDS).

    • D. 

      Situation awareness data link (SADL).

  • 80. 
    Which type of advanced waveform was designed to operate on manned, vehicular-based communication systems?
    • A. 

      Soldier radio

    • B. 

      Wideband networking

    • C. 

      Mobile user objective system

    • D. 

      Adaptive network wideban waveform

  • 81. 
    Which type of advanced waveform enables data and imagery situational awareness and provides enhanced combat effectiveness?
    • A. 

      Soldier radio

    • B. 

      Wideband networking

    • C. 

      Mobile user objective system

    • D. 

      Adaptive network wideband waveform

  • 82. 
    In high-frequency (HF) communications, your station’s automatic link establishment (ALE) self-address is the address
    • A. 

      the user programmed for his or her station.

    • B. 

      it shares with other members.

    • C. 

      Of an unprogrammed station

    • D. 

      Of other stations in the net

  • 83. 
    This is the simplest form of an automatic link establishment (ALE) call.
    • A. 

      All

    • B. 

      Any

    • C. 

      Group

    • D. 

      Individual

  • 84. 
    Which automatic link establishment (ALE) call option lets you call a predefined group of stations with a single shared address, and requires them to respond, one at a time, in a predefined order?
    • A. 

      Handshake

    • B. 

      Channel

    • C. 

      Group

    • D. 

      Net

  • 85. 
    Where is the primary high frequency global communications system (HFGCS) network control station located?
    • A. 

      Offutt, Nebraska.

    • B. 

      Grand Forks, North Dakota

    • C. 

      Andrews AFB, Maryland

    • D. 

      Croughton, England.

  • 86. 
    This is not a major network within the Military Auxiliary Radio Service (MARS).
    • A. 

      MSN

    • B. 

      PPN

    • C. 

      VHF

    • D. 

      UHF

  • 87. 
    The process of unscrambling encrypted information so that it is intelligible is known as
    • A. 

      Decryption

    • B. 

      Encryption

    • C. 

      Cryptography

    • D. 

      Cryptanalysis

  • 88. 
    Which type of cryptographic algorithm permits the encryption key to be public?
    • A. 

      Asymmetric

    • B. 

      Symmetric

    • C. 

      Encoder

    • D. 

      Secret

  • 89. 
    Which secure communications device operates by simply sliding the key tape into the reader?
    • A. 

      Kyk-13

    • B. 

      Koi-18

    • C. 

      Ky-57

    • D. 

      Ky-99a

  • 90. 
    The common name for the method of changing encryption keys over the radio channel in a two-way radio system is called
    • A. 

      OTAR

    • B. 

      Asymmetric

    • C. 

      Symmetric

    • D. 

      Off-line

  • 91. 
    Which type of conventional land mobile radio (LMR) device maximizes the communications distance between lower-powered equipment items?
    • A. 

      Mobile

    • B. 

      Portable

    • C. 

      Repeater

    • D. 

      Base station

  • 92. 
    In a land mobile radio (LMR) repeater system, a device that separates and isolates the incoming receive signal from the outgoing transmit signal and vice versa is known as a
    • A. 

      Duplexer

    • B. 

      Comparator

    • C. 

      Key-unkey relay

    • D. 

      Transmit-receive switch

  • 93. 
    Which type of site configuration was designed to provide coverage for a small geographical area?
    • A. 

      Single-site

    • B. 

      Multi-site

    • C. 

      Simulcast

    • D. 

      Multicast

  • 94. 
    This provides the interface between dispatch consoles and the central controller in a typical trunking system.
    • A. 

      Modems

    • B. 

      Access control

    • C. 

      Switching equipment

    • D. 

      System management computer

  • 95. 
    When setting up a trunking network, users with common missions or functions are assigned as 
    • A. 

      Nets

    • B. 

      Channels

    • C. 

      Talkgroups

    • D. 

      Subscribers

  • 96. 
    Which statement is not a benefit of having a trunking network?
    • A. 

      Selective radio inhibit

    • B. 

      Faster system access

    • C. 

      Unbalanced channel loads

    • D. 

      Better channel efficiency

  • 97. 
    This differentiates the enterprise land mobile radio (ELMR) network from a regular trunking or conventional network.
    • A. 

      Advanced encryption standard (AES) encryption.

    • B. 

      Association of Public-Safety Communications Officials (APCO) P25 standard.

    • C. 

      Repeater.

    • D. 

      Centralized core controller

  • 98. 
    Which Air Force instruction (AFI) requires communications squadrons to maintain installation notification and warning systems (INWS)?
    • A. 

      AFI 10–2501, Air Force Emergency Management Program.

    • B. 

      AFI 10–2801, Force Development Concepts.

    • C. 

      AFI 33–115, Air Force Information Technology Service Management.

    • D. 

      AFI 33–217, Voice Call Sign Program.

  • 99. 
    In the giant-voice system, this controls the system’s signal routing and power distribution.
    • A. 

      Landline board

    • B. 

      Control board

    • C. 

      Radio board

    • D. 

      Encoder

  • 100. 
    Which is not a major component of the giant-voice system?
    • A. 

      Siren cabinet

    • B. 

      Siren stack

    • C. 

      Decoder

    • D. 

      Encoder