The GATE Grind

GATE 2024 CE (CE1) – Question 27

Geomatics Engineering · Distance and angle measurement, levelling, traversing, triangulation, total station · 1 mark · Multiple choice

Among the following statements relating the fundamental lines of a transit theodolite, which one is CORRECT?

  1. The line of collimation must be perpendicular to the horizontal axis at its intersection with the vertical axis.
  2. The axis of altitude level must be perpendicular to the line of collimation.
  3. The axis of plate level must lie in a plane parallel to the vertical axis.
  4. The Vernier of vertical circle must read zero when the line of collimation is vertical.

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Show answer and explanation

Correct answer: (A) The line of collimation must be perpendicular to the horizontal axis at its intersection with the vertical axis.

Explanation

The fundamental relations are: the axis of the plate level is perpendicular to the vertical axis (so C is false), the line of collimation is perpendicular to the horizontal axis and cuts the vertical axis (A is true), the horizontal axis is perpendicular to the vertical axis, and the vertical circle vernier reads zero when the line of collimation is horizontal (D is false). The altitude level axis is parallel to the line of collimation (B is false).