GATE CE 2024 Set 1 — Question 27

MCQ+1 / -0.33MediumTheodolite SurveyingDistance & Angle MeasurementGeomatics Engineering

Geomatics Engineering → Distance & Angle Measurement → Theodolite Surveying

Last updated 5 September 2026

Question

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

Correct answer (A) The line of collimation must be perpendicular to the horizontal axis at its intersection with the vertical axis. Solution The fundamental lines and their required relationships in a transit theodolite are: 1. Axis of plate level must be perpendicular to the vertical axis . 2. Line of collimation must be perpendicular to the horizontal axis (trunnion axis). 3. Horizontal axis must be perpendicular to the vertical axis . 4. Axis of altitude level must be parallel to the line of collimation . 5. Vertical circle reading must be zero when the line of collimation is horizontal. Evaluating the options: (A) CORRECT : The line of collimation must be perpendicular to the horizontal axis. (B) INCORRECT : The axis of altitude level must be parallel to the line of collimation. (C) INCORRECT : The axis of plate level must be perpendicular to the vertical axis. (D) INCORRECT : The vertical circle must read zero when the line of collimation is horizontal, not vertical. Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (A) The line of collimation must be perpendicular to the horizontal axis at its intersection with the vertical axis. Solution The fundamental lines and their required relationships in a transit theodolite are: 1. Axis of plate level must be perpendicular to the vertical axis . 2. Line of collimation must be perpendicular to the horizontal axis (trunnion axis). 3. Horizontal axis must be perpendicular to the vertical axis . 4. Axis of altitude level must be parallel to the line of collimation . 5. Vertical circle reading must be zero when the line of collimation is horizontal. Evaluating the options: (A) CORRECT : The line of collimation must be perpendicular to the horizontal axis. (B) INCORRECT : The axis of altitude level must be parallel to the line of collimation. (C) INCORRECT : The axis of plate level must be perpendicular to the vertical axis. (D) INCORRECT : The vertical circle must read zero when the line of collimation is horizontal, not vertical.

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