Which of the following errors cannot be eliminated by taking both face observations ?
A)error due to horizontal axis not being perpendicular to the vertical axis
B)index error i.e. error due to imperfect adjustment of the vertical circle vernier
C)error due to non-parallelism of the axis of telescope level and line of collimation
D)none of the above

Question

Quizplus · Accepted Answer

Taking both face observations helps in eliminating systematic errors by averaging them out. However, the errors listed in options A, B, and C are systematic errors that can indeed be eliminated or minimized by taking observations in both faces (direct and reverse positions) of the instrument. Therefore, none of the errors listed are exceptions to this rule, making D the correct choice.

Which of the Following Errors Cannot Be Eliminated by Taking