49. The advantage of reciprocal levelling is that
(A) It eliminates the error due to curvature and refraction
(B) It eliminates collimation error
(C) Both (A) and (B)
(D) None of these

50. System of levelling chiefly employed for establishing bench marks with high
precision is
(A) Longitudinal levelling (B) Fly levelling

(C) Profile levelling (D) Precise levelling

51. A line laying on the ground maintaining a constant inclination to the horizontal is

known as
(A) Grade contour (B) Contour line
(C) Agonic lines (D) Isoclinic lines

52. The line of sight may not be perpendicular to the vertical axis in case of
(A) Dumpy level (B) The Wye level
(C) Tilting level (D) None of the above

53. While traversing anticlockwise a closed traverse of n sides, theoretical sum of included
angles should be

(A) 360° (8) (27 - 4) x 90
(C) (2n +4) x90 (D) (2n +4) x 90

54. In Bowditch rule of traverse adjustment it is assumed that errors in the linear
measurements are

(A) Inversely proportional to VL (B) Proportional to VL
(C) Proportional L (D) Inversely Proportional L

55. The process of establishing intermediate points, between two end points which are
not intervisible, with the help of a theodolite is known as.

(A) Interpolation (B) Balancing-in
(C) Ranging (D) Lining-in
56. Thebench mark established by the survey of India department with very high precision
with reference to mean sea level at Karachi as the datum are called
(A) Permanent Bench Mark (B) G.T.S. Bench Marks
(C) Arbitrary Bench Marks (D) Temporary Bench Marks

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