A. the length of telescope
B. the diameter of vertical circle
C. the diameter of lower plate
D. the diameter of upper plate
A. on its outer spindle with a relative motion between the vernier and graduated scale of lower plate
B. on its outer spindle without a relative motion between the vernier and gra-duated scale of lower plate
C. on its inner spindle with a relative motion between the vernier and the graduated scale of lower plate
D. on its inner spindle without a relative motion between the vernier and the graduated scale of lower plate
A. adjustment of plate levels
B. adjustment of line of sight
C. adjustment of horizontal axis
D. adjustment of altitude bubble and vertical index frame
A. error due to eccentricity of verniers
B. error due to displacement of station signals
C. error due to wrong adjustment of line of collimation and trunnion axis
D. error due to inaccurate graduation
A. midway between eye piece and objec¬tive lens
B. much closer to the eye-piece than to the objective lens
C. much closer to the objective lens than to the eye piece
D. anywhere between eye-piece and objective lens
A. leveling
B. prolonging a straight line
C. measurement of horizontal angles
D. all of the above
A. reading both verniers and taking the mean of the two
B. taking both face observations and taking the mean of the two
C. double sighting
D. taking mean of several readings distributed over different portions of the graduated circle
A. concave
B. convex
C. plano-convex
D. plano-concave
A. backsight
B. intermediate sight
C. foresight
D. all of the above