3–11. Which of the following IFF mode 3/A reply codes will trigger an alarm at an FAA tower? 1. 7500 2. 7600 3. 7777 4. All of the above 3-12. Which of the following IFF mode 3/A reply codes may your ship use in U.S.    national  air  space? 1. 5011 2. 5247 3. 6247 4. 6539 3–13. Which of the following IFF mode C reply codes will your ship use? 1. 3564 2. 5732 3. 6534 4. 0000 3–14. A  commercial  airliner  using  TCAS could mistake your ship’s IFF mode C reply for which of the following structures? 1. An airport tower 2. A  small  aircraft  flying  at about  14,000  feet 3. A small aircraft flying at about  10,000  feet 4. A bigger ship 3–15. Under which of the following circumstances  may  you  operate  IFF in mode C when your ship is in or near  port? 1. In heavy air traffic areas 2. To make contact with the FAA tower 3. When  performing  operational testing 4. When  testing  with  the  antenna disconnected 3–16. The MK XII IFF system requires triggers  to  initiate  interro– gations. Where do they come from? 1. The  modulator  of  the  primary radar 2. The pulse generator of the IFF interrogator 3. Both 1 and 2 above 4. The  KIR–1A/TSEC 3-17. You  would  find  direct  altitude readouts for IFF mode C replies on which of the following displays? 1. Planned  position  indicator 2. Range  and  height  indicator 3. Intratarget  data  indicator 4. Alarm  monitor 3-18. All the indicators on your ship that are interfaced with IFF have ring-around. Which of the following  places  will  the  problem most likely be found? 1. Primary  radar  antenna 2. Radar  distribution  switchboard 3. IFF  interrogator  section 4. IFF  transponder  section 3–19. The  antenna  pedestal  assembly  is being rotated at 21 rpm. To what mode of operation is your IFF manual pedestal set? 1. Free  run 2. Slave 3. Manual 4. Auto 3–20. Which of the following modes of IFF  operation  does/do  NOT  require that reply codes be set by thumbwheel  switches? 1. 3/A 2.   C 3. 4 4. Both 2 and 3 above 13