50. Which one of the following statements is not relevant to hydrographic survey :
A. establishment of a chain of bench marks near the shore line
B. establishment of horizontal control points on the shore
C. determination of the sea bed profile
D. none of these.
51. The shore line survey includes :
A. depicting the shore line
B. depicting the prominent details on shore line
C. depicting the high water line
D. all the above.
52. Soundings are required for
A. making nautical charts for navigation
B. ascertaining the areas subject to scour or silting
C. obtaining detailed information for construction
D. all the above.
53. A lead line or sounding line
A. is stretched thoroughly when wet before it is graduated
B. should be soaked in water for about one hour prior to taking soundings
C. is adjusted at regular interval
D. all the above.
54. The low water datum for a lake is defined as the surface of the lake when it is at elevation
A. 180,5 m above M.S.L.
B. 190.5 m above M.S.L.
C. 170.5 m above M.S.L.
D. 200.0 m above M.S.L.
55. For location of soundings a range and one angle from the shore involves the following operations. Which one is correct ?
A. A range line is established
B. The first and the last soundings and every tenth soundings are fixed by angular observations
C. The intermediate soundings are fixed by the time intervals
D. All the above.
56. Location of soundings by range and one angle is done by the surveyor
A. on the shore
B. on the boat
C. on the shore or on the boat
D. none of the above,
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