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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 401–500 of 605 · page 5 of 7

  1. #401 If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission...
  2. #402 What is the effective radiated power of a repeater with 50 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and...
  3. #403 What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and...
  4. #404 What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and...
  5. #405 What is the effective radiated power of a repeater with 100 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and...
  6. #406 What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and...
  7. #407 What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and...
  8. #408 What is the frequency range of the Distance Measuring Equipment (DME) used to indicate an aircraft's slant range distance to a selected ground-based n...
  9. #409 The Distance Measuring Equipment (DME) measures the distance from the aircraft to the DME ground station. This is referred to as:
  10. #410 The Distance Measuring Equipment (DME) ground station has a built-in delay between reception of an interrogation and transmission of the reply to allo...
  11. #411 What is the main underlying operating principle of an aircraft's Distance Measuring Equipment (DME)?
  12. #412 What radio navigation aid determines the distance from an aircraft to a selected VORTAC station by measuring the length of time the radio signal takes...
  13. #413 The majority of airborne Distance Measuring Equipment systems automatically tune their transmitter and receiver frequencies to the paired __ / __ chan...
  14. #414 All directions associated with a VOR station are related to:
  15. #415 The rate that the transmitted VOR variable signal rotates is equivalent to how many revolutions per second?
  16. #416 What is the frequency range of the ground-based Very-high-frequency Omnidirectional Range (VOR) stations used for aircraft navigation?
  17. #417 Lines drawn from the VOR station in a particular magnetic direction are:
  18. #418 The amplitude modulated variable phase signal and the frequency modulated reference phase signal of a Very-high-frequency Omnidirectional Range (VOR)...
  19. #419 What is the main underlying operating principle of the Very-high-frequency Omnidirectional Range (VOR) aircraft navigational system?
  20. #420 What is the frequency range of the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS)...
  21. #421 What is the frequency range of the marker beacon system used to indicate an aircraft's position during an Instrument Landing System (ILS) approach to...
  22. #422 Which of the following is a required component of an Instrument Landing System (ILS)?
  23. #423 What type of antenna is used in an aircraft's Instrument Landing System (ILS) glideslope installation?
  24. #424 Choose the only correct statement about the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing Sys...
  25. #425 On runway approach, an ILS Localizer shows:
  26. #426 What is the frequency range of an aircraft's Automatic Direction Finding (ADF) equipment?
  27. #427 What is meant by the term night effect" when using an aircraft's Automatic Direction Finding (ADF) equipment? Night effect refers to the fact that:"
  28. #428 What are the transmit and receive frequencies of an aircraft's mode C transponder operating in the Air Traffic Control RADAR Beacon System (ATCRBS)?
  29. #429 In addition to duplicating the functions of a mode C transponder, an aircraft's mode S transponder can also provide:
  30. #430 What type of encoding is used in an aircraft's mode C transponder transmission to a ground station of the Air Traffic Control RADAR Beacon System (ATC...
  31. #431 Choose the only correct statement about an aircraft's Automatic Direction Finding (ADF) equipment.
  32. #432 What type of antenna pattern is radiated from a ground station phased-array directional antenna when transmitting the PPM pulses in a Mode S interroga...
  33. #433 What type of antenna is used in an aircraft's Instrument Landing System (ILS) marker beacon installation?
  34. #434 What is the frequency range of an aircraft's Very High Frequency (VHF) communications?
  35. #435 Aircraft Emergency Locator Transmitters (ELT) operate on what frequencies?
  36. #436 What is the frequency range of an aircraft's radio altimeter?
  37. #437 What type of antenna is attached to an aircraft's Mode C transponder installation and used to receive 1030 MHz interrogation signals from the Air Traf...
  38. #438 Some aircraft and avionics equipment operates with a prime power line frequency of 400 Hz. What is the principle advantage of a higher line frequency?
  39. #439 Aviation services use predominantly ____ microphones.
  40. #440 Typical airborne HF transmitters usually provide a nominal RF power output to the antenna of ____ watts, compared with ____ watts RF output from a typ...
  41. #441 Before ground testing an aircraft RADAR, the operator should:
  42. #442 What type of antenna is used in an aircraft's Very High Frequency Omnidirectional Range (VOR) and Localizer (LOC) installations?
  43. #443 What is the function of a commercial aircraft's SELCAL installation? SELCAL is a type of aircraft communications __________.
  44. #444 What is a 1/2 digit on a DMM?
  45. #445 A 50 microampere meter movement has an internal resistance of 2,000 ohms. What applied voltage is required to indicate half-scale deflection?
  46. #446 What is the purpose of a series multiplier resistor used with a voltmeter?
  47. #447 What is the purpose of a shunt resistor used with an ammeter?
  48. #448 What instrument is used to indicate high and low digital voltage states?
  49. #449 What instrument may be used to verify proper radio antenna functioning?
  50. #450 How is a frequency counter used?
  51. #451 What is a frequency standard?
  52. #452 What equipment may be useful to track down EMI aboard a ship or aircraft?
  53. #453 On an analog wattmeter, what part of the scale is most accurate and how much does that accuracy extend to the rest of the reading scale?
  54. #454 Which of the following frequency standards is used as a time base standard by field technicians?
  55. #455 Which of the following contains a multirange AF voltmeter calibrated in dB and a sharp, internal 1000 Hz bandstop filter, both used in conjunction wit...
  56. #456 What is used to decrease circuit loading when using an oscilloscope?
  57. #457 How does a spectrum analyzer differ from a conventional oscilloscope?
  58. #458 What stage determines the maximum frequency response of an oscilloscope?
  59. #459 What factors limit the accuracy, frequency response, and stability of an oscilloscope?
  60. #460 An oscilloscope can be used to accomplish all of the following except:
  61. #461 What instrument is used to check the signal quality of a single-sideband radio transmission?
  62. #462 A(n) ____ and ____ can be combined to measure the characteristics of transmission lines. Such an arrangement is known as a time-domain reflectometer (...
  63. #463 What does the horizontal axis of a spectrum analyzer display?
  64. #464 What does the vertical axis of a spectrum analyzer display?
  65. #465 What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna?
  66. #466 What test instrument can be used to display spurious signals in the output of a radio transmitter?
  67. #467 What instrument is commonly used by radio service technicians to monitor frequency, modulation, check receiver sensitivity, distortion, and to generat...
  68. #468 Can a P25 radio system be monitored with a scanner?
  69. #469 Which of the following answers is true?
  70. #470 What is a common method used to program radios without using a wired" connection?"
  71. #471 What is the common method for determining the exact sensitivity specification of a receiver?
  72. #472 A communications technician would perform a modulation-acceptance bandwidth test in order to:
  73. #473 What is the maximum FM deviation for voice operation of a normal wideband channel on VHF and UHF?
  74. #474 When soldering or working with CMOS electronics products or equipment, a wrist strap:
  75. #475 Which of the following is the preferred method of cleaning solder from plated-through circuit-board holes?
  76. #476 What is the proper way to cut plastic wire ties?
  77. #477 The ideal method of removing insulation from wire is:
  78. #478 A hot gas bonder" is used:"
  79. #479 When repairing circuit board assemblies it is most important to:
  80. #480 What color is the binder for pairs 51-75 in a 100-pair cable?
  81. #481 What is most important when routing cables in a mobile unit?
  82. #482 Why should you not use white or translucent plastic tie wraps on a radio tower?
  83. #483 What is the 6th pair color code in a 25 pair switchboard cable as is found in building telecommunications interconnections?
  84. #484 What tolerance off of plumb should a single base station radio rack be installed?
  85. #485 What type of wire would connect an SSB automatic tuner to an insulated backstay?
  86. #486 On a 150 watt marine SSB HF transceiver, what would be indicated by a steady output of 75 watts when keying the transmitter on?
  87. #487 The tachometer of a building's elevator circuit experiences interference caused by the radio system nearby. What is a common potential fix" for the pr...
  88. #488 A common method of programming portable or mobile radios is to use a:
  89. #489 In a software-defined transceiver, what would be the best way for a technician to make a quick overall evaluation of the radio's operational condition...
  90. #490 How might an installer verify correct GPS sentence to marine DSC VHF radio?
  91. #491 What steps must be taken to activate the DSC emergency signaling function on a marine VHF?
  92. #492 What term describes a wide-bandwidth communications system in which the RF carrier frequency varies according to some predetermined sequence?
  93. #493 Name two types of spread spectrum systems used in most RF communications applications?
  94. #494 What is the term used to describe a spread spectrum communications system where the center frequency of a conventional carrier is altered many times p...
  95. #495 A TDMA radio uses what to carry the multiple conversations sequentially?
  96. #496 Which of the following statements about SSB voice transmissions is correct?
  97. #497 What are the two most-used PCS (Personal Communications Systems) coding techniques used to separate different calls?
  98. #498 What is a CODEC?
  99. #499 The GSM (Global System for Mobile Communications) uses what type of CODEC for digital mobile radio system communications?
  100. #500 Which of the following codes has gained the widest acceptance for exchange of data from one computer to another?

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.