7-28. The Beaman stadia arc uses which of the  following  methods  to  determine horizontal   distances? 1. Multiplier  scale 2. Addition  scale 3. Indirect  scale 4. Subtraction  scale 7-29. The rod intercept is 3.75 for point B. The H scale on the Beaman arc reads 10. What is the horizontal distance from the instrument to point B? 1. 337.5  ft 2. 371.3  ft 3. 378.8  ft 4. 412.5  ft 7-30. You have a reading of 80 on the V scale of the Beaman stadia arc. The rod intercept is 3.75. What is the  difference  in  elevation  between the  instrument  and  the  point sighted? 1. -10.25 ft 2. +10.25 ft 3. -30.00 ft 4. +30.00 ft 7-31. Which of the following procedures should  you  follow  in  determining the vertical angle of a point in a transit-stadia   method? 1. Read the angle when the lower stadia  hair  intercepts  the graduation  mark  on  the  stadia rod that corresponds to the actual HI above the ground surface 2. Read the angle when the upper stadia  hair  intercepts  the graduation  mark  on  the  stadia rod that corresponds to the actual HI 3. Read the angle when the horizontal  stadia  hair intercepts  the  graduation  mark on the stadia rod that corresponds to the actual HI above  the  ground  surface 4. Read the angle when the vertical  stadia  hair  intercepts the graduation mark on the stadia  rod  that  corresponds  to the actual HI above the ground surface 7-32. What  method  is  used  to  determine the  instrument  height? 1. Take a rod reading on the point before  the  instrument  setup 2. Use a tape or rod to measure the height after setting up over  the  point 3. Use  balanced  foresights  and backsights  and  then  obtain  an average 4. Set the instrument up to your eye  alignment IN  ANSWERING  QUESTIONS  7-33  THROUGH  7-36, REFER TO APPENDIX II, TABLE AII-3. ALSO USE  THE  FOLLOWING  INFORMATION: Elevation station A = 525.3 ft Rod reading on point  B 4.3 HI 4.3 ft Stadia  interval 6.1 Vertical angle to  B +5°20’ Focal length 0.75 48