Surveying - Engineering

Q1:

In horizontal angles, the error due to imperfect levelling of the plate bubble is

A large when sights are nearly level

B large for long sights

C less for steeply inclined sights

D large for steeply inclined sights.

ANS:D - large for steeply inclined sights.

Error due to imperfect levelling of the plate bubble will give rise to inclined in its vertical axis. And hence, the measured angle are not truly horizontal angle. So, Larger the vertical angle, greater the error in direction.