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Element 3
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GMDSS · 605 questions

Element 3 - USCG Exam Questions

General radiotelephone operator knowledge: radio law and regulations, operating procedures, and radio equipment fundamentals.

Every question below is a real U.S. Coast Guard exam question with four choices. Answer one and the correct choice is revealed instantly, with the USCG reference and illustration where the question uses one.

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All Element 3 questions

Questions 501–600 of 605 · page 6 of 7

  1. #501 The International Organization for Standardization has developed a seven-level reference model for a packet-radio communications structure. What level...
  2. #502 What CODEC is used in Phase 2 P25 radios?
  3. #503 The International Organization for Standardization has developed a seven-level reference model for a packet-radio communications structure. The ______...
  4. #504 What is a SDR?
  5. #505 What does the DSP not do in a modern DSP radio?
  6. #506 Which statement best describes the code used for GMDSS-DSC transmissions?
  7. #507 Which is the code used for SITOR-A and -B transmissions?
  8. #508 Which of the following statements is true?
  9. #509 What principle allows multiple conversations to be able to share one radio channel on a GSM channel?
  10. #510 What is the channel spacing used for VHF marine radio?
  11. #511 What VHF channel is assigned for distress and calling?
  12. #512 What VHF Channel is used for Digital Selective Calling and acknowledgement?
  13. #513 Maximum allowable frequency deviation for VHF marine radios is:
  14. #514 What is the reason for the USA-INT control or function?
  15. #515 How might an installer verify correct GPS sentence to marine DSC VHF radio?
  16. #516 What is a common occurrence when voice-testing an SSB aboard a boat?
  17. #517 What might contribute to apparent low voltage on marine SSB transmitting?
  18. #518 What type of wire connects an SSB automatic tuner to an insulated backstay?
  19. #519 Which of the following statements concerning SITOR communications is true?
  20. #520 The sequence ARQ, FEC, SFEC best corresponds to which of the following sequences?
  21. #521 Which of the following statements concerning SITOR communications is true?
  22. #522 What causes the SART to begin a transmission?
  23. #523 How should the signal from a Search And Rescue RADAR Transponder appear on a RADAR display?
  24. #524 In which frequency band does a search and rescue transponder operate?
  25. #525 Which piece of required GMDSS equipment is the primary source of transmitting locating signals?
  26. #526 Which of the following statements concerning satellite EPIRBs is true?
  27. #527 What statement is true regarding 406 MHz EPIRB transmissions?
  28. #528 What is facsimile?
  29. #529 What is the standard scan rate for high-frequency 3 MHz - 23 MHz weather facsimile reception from shore stations?
  30. #530 What would be the bandwidth of a good crystal lattice band-pass filter for weather facsimile HF (high frequency) reception?
  31. #531 Which of the following statements about NAVTEX is true?
  32. #532 Which of the following is the primary frequency that is used exclusively for NAVTEX broadcasts internationally?
  33. #533 What determines whether a NAVTEX receiver does not print a particular type of message content?
  34. #534 What data language is bi-directional, multi-transmitter, multi-receiver network?
  35. #535 How should shielding be grounded on an NMEA 0183 data line?
  36. #536 What might occur in NMEA 2000 network topology if one device in line should fail?
  37. #537 In an NMEA 2000 device, a load equivalence number (LEN) of 1 is equivalent to how much current consumption?
  38. #538 An NMEA 2000 system with devices in a single location may be powered using this method:
  39. #539 What voltage drop at the end of the last segment will satisfy NMEA 2000 network cabling plans?
  40. #540 What is the normal range of pulse repetition rates?
  41. #541 The RADAR range in nautical miles to an object can be found by measuring the elapsed time during a RADAR pulse and dividing this quantity by:
  42. #542 What is the normal range of pulse widths?
  43. #543 Shipboard RADAR is most commonly operated in what band?
  44. #544 The pulse repetition rate (prr) of a RADAR refers to the:
  45. #545 If the elapsed time for a RADAR echo is 62 microseconds, what is the distance in nautical miles to the object?
  46. #546 The ATR box:
  47. #547 What is the purpose or function of the RADAR duplexer/circulator? It is a/an:
  48. #548 What device can be used to determine the performance of a RADAR system at sea?
  49. #549 What is the purpose of a synchro transmitter and receiver?
  50. #550 Digital signal processing (DSP) of RADAR signals (compared with analog) causes:
  51. #551 The component or circuit providing the transmitter output power for a RADAR system is the:
  52. #552 When a RADAR is being operated on the 48 mile range setting, what is the most appropriate pulse width (PW) and pulse repetition rate (pps)?
  53. #553 When a RADAR is being operated on the 6 mile range setting what is the most appropriate pulse width and pulse repetition rate?
  54. #554 We are looking at a target 25 miles away. When a RADAR is being operated on the 25 mile range setting what is the most appropriate pulse width and pul...
  55. #555 What pulse width and repetition rate should you use at long ranges?
  56. #556 What pulse width and repetition rate should you use at short ranges?
  57. #557 When a RADAR is being operated on the 1.5 mile range setting, what is the most appropriate pulse width and pulse repetition rate?
  58. #558 How does the gain of a parabolic dish antenna change when the operating frequency is doubled?
  59. #559 What type of antenna or pickup device is used to extract the RADAR signal from the wave guide?
  60. #560 What happens to the beamwidth of an antenna as the gain is increased? The beamwidth:
  61. #561 A common shipboard RADAR antenna is the:
  62. #562 Conductance takes place in a waveguide:
  63. #563 To couple energy into and out of a waveguide use:
  64. #564 The permanent magnetic field that surrounds a traveling-wave tube (TWT) is intended to:
  65. #565 Prior to testing any RADAR system, the operator should first:
  66. #566 In the term "ARPA RADAR," ARPA is the acronym for which of the following?
  67. #567 Which of the following is NOT a precaution that should be taken to ensure the magnetron is not weakened:
  68. #568 Exposure to microwave energy from RADAR or other electronics devices is limited by U.S. Health Department regulations to _______ mW/centimeter.
  69. #569 RADAR collision avoidance systems utilize inputs from each of the following except your ship's:
  70. #570 What is the orbiting altitude of the Iridium satellite communications system?
  71. #571 What frequency band is used by the Iridium system for telephone and messaging?
  72. #572 What services are provided by the Iridium system?
  73. #573 Which of the following statements about the Iridium system is true?
  74. #574 What is the main function of the COSPAS-SARSAT satellite system?
  75. #575 How does the COSPAS-SARSAT satellite system determine the position of a ship in distress?
  76. #576 What is the orbital altitude of INMARSAT Satellites?
  77. #577 Which of the following describes the INMARSAT Satellite system?
  78. #578 What are the directional characteristics of the INMARSAT-C SES antenna?
  79. #579 When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?
  80. #580 Which of the following statements concerning INMARSAT geostationary satellites is true?
  81. #581 Which of the following conditions can render INMARSAT -B communications impossible?
  82. #582 What is the best description for the INMARSAT-C system?
  83. #583 The INMARSAT mini-M system is a:
  84. #584 What statement best describes the INMARSAT-B services?
  85. #585 Which INMARSAT systems offer High Speed Data at 64/54 kbps?
  86. #586 When INMARSAT-B and INMARSAT-C terminals are compared:
  87. #587 What services are provided by the INMARSAT-M service?
  88. #588 Global Positioning Service (GPS) satellite orbiting altitude is:
  89. #589 The GPS transmitted frequencies are:
  90. #590 How many GPS satellites are normally in operation?
  91. #591 What best describes the GPS Satellites orbits?
  92. #592 How many satellites must be received to provide complete position and time?
  93. #593 What is DGPS?
  94. #594 Compliance with MPE, or Maximum Permissible Exposure to RF levels (as defined in FCC Part 1, OET Bulletin 65) for "controlled" environments, are avera...
  95. #595 Sites having multiple transmitting antennas must include antennas with more than _______% of the maximum permissible power density exposure limit when...
  96. #596 RF exposure from portable radio transceivers may be harmful to the eyes because:
  97. #597 At what aggregate power level is an MPE (Maximum Permissible Exposure) study required?
  98. #598 Why must you never look directly into a fiber optic cable?
  99. #599 If the MPE (Maximum Permissible Exposure) power is present, how often must the personnel accessing the affected area be trained and certified?
  100. #600 What device can protect a transmitting station from a direct lightning hit?

Element 3 questions: what to expect

Q How many Element 3 questions are in the GMDSS pool?

There are 605 Element 3 questions on this site, every one released by the U.S. Coast Guard or taken from the National Maritime Center's sample examinations, with its correct answer. The exam draws its Element 3 module from the same pool.

Q What score do I need to pass the Element 3 module?

Most USCG exam modules, including Element 3, require 70 percent to pass. Rules of the Road modules require 90 percent.

Q Are these the real USCG Element 3 exam questions?

Yes. They are the published U.S. Coast Guard questions, matched to the National Maritime Center's 2026 sample examinations. Answer any question to see the correct choice, the USCG reference and the illustration where the question uses one.

About the GMDSS question pool

These are the published GMDSS Element 3 questions covering general radiotelephone operator knowledge: radio law, operating procedures, and equipment fundamentals.