9-11. 9-12. 9-13. 9-14. 9-15. 9-16. When  the  reflected  object  is sighted in the horizon glass, how should the object be positioned in relation  to  the  visible  horizon? 1.    Slightly above horizon 2.    Slightly  below  horizon 3.    Placed on or even with the horizon In  what  increments  is  the  vernier scale  graduated? 1.    Tenths  of  minutes 2.    Seconds 3.    Minutes 4.    Degrees When a sextant is used, how often should  the  index  error  be  checked? 1.   During  PMS 2.    Before the sextant is used 3.    Before each sighting 4.    After the sextant is used A sextant's index error can not be adjusted. 1.    True 2.    False If the sextant has no index error, the  reflected  horizon  and  the visible  horizon  will  coincide. 1.    True 2.    False You have sighted on the horizon to determine  the  index  correction  of  a sextant. The index mark falls on the arc just to the left of the 0° line. If the drum and vernier read 9.4', what is the index correction, and how is it applied? 1.    + 50.6' - added 2. + 9.4' - subtracted 3. - 50.6' - subtracted 4. - 9.4' - added 9-17. You have sighted on the horizon to determine  the  index  correction  of  a sextant. The index mark falls on the arc just to the right of the 0° line. If the drum and vernier read 3.7', what is the index correction, and how is it applied? 1. - 3.7' - added 2. - 56.3' - added 3. + 3.7' - added 4. + 56.3' - subtracted 9-18. 9-19. 9-20. 9-21. 9-22. 9-23. 9-24. Which  of  the  following  methods  of fixing a ship's position is the most accurate? 1.    Taking a range and bearing to a single  object 2.    Establishing  intersecting  lines of  position  with  bearings  of two or more objects 3.    Taking  horizontal  sextant angles between three fixed objects 4.   Taking  successive  bearings  of  a single  fixed  object To  shoot  sextant  angles,  you  must have a total of how many objects? 1. One 2.    Two 3.    Three 4.    Four When you shoot sextant angles, how should the two images look? 1.   The middle object should be to the left 2.    The middle object should be to the right 3.    One image above the other 4.    The  two  images  should  coincide What instrument is used to plot a position  obtained  by  horizontal sextant  angles? 1.    Dead-reckoning   tracer 2.    Dividers 3.    Parallel  rulers 4.    Three-arm   protractor To  what  accuracy  can  a  three-arm protractor  be  plotted? 1.   Nearest  second  of  arc 2.   Nearest  tenth  of  degree 3.   Nearest  minute  of  arc 4.   Nearest  degree Which  of  the  following  terms defines  the  circumference  of  a circle,  when  sextant  angles  are used? 1.    Swinger  only 2.    Pivot 3.    Revolver  only 4.    Swinger  or  revolver The  pivot  point  of  a  three-arm protractor  is  the  ship's  position. 1.    True 2.    False 56