Surveying - Engineering

Q1:

When the bubble of the level tube of a level, remains central

A line of sight is horizontal

B axis of the telescope is horizontal

C line of collimation is horizontal

D geometrical axis of the telescope is horizontal.

ANS:A - line of sight is horizontal

Line of collimation is only horizontal in levelling operation, in case of finding angles, we call it line of sight, not line of collimation. Line of collimation is only horizontal but line of sight is inclined or horizontal. Line of sight is horizontal is the correct answer. The line of sight and line of collimation is same.