Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
Which of the following is an integral part of the theodolite and is mounted on a spindle known as a horizontal axis?
Telescope
Index frame
Horizontal Circle
Vernier
Telescope
The telescope is a primary component of the theodolite that facilitates sighting objects. It is mounted on the trunnion axis, also known as the horizontal axis, allowing it to rotate in a vertical plane for measuring vertical angles and reading target elevations.
The telescope is a primary component of the theodolite that facilitates sighting objects. It is mounted on the trunnion axis, also known as the horizontal axis, allowing it to rotate in a vertical plane for measuring vertical angles and reading target elevations.
V=Htan(θ) — The relationship between horizontal distance H and vertical angle θ to determine vertical displacement V
D=kS+c — The basic stadia intercept formula used with the telescope for distance measurement
The horizontal axis (trunnion axis) acts as a pivot point for the telescope. By rotating the telescope around this axis, the surveyor can change the vertical pointing of the instrument. This rotational mechanism is essential for performing transiting (plunging) and measuring the angle of elevation or depression relative to the horizontal plane.
The telescope is a main component responsible for precise pointing.
The horizontal axis allows vertical motion of the telescope (transiting).
The theodolite uses two main axes: the vertical axis (for horizontal angles) and the horizontal axis (for vertical angles).
Transiting is the process of revolving the telescope 180° about its horizontal axis.
High precision in both horizontal and vertical angle measurement.
Versatility in various surveying applications like traversing, triangulation, and leveling.
Requires high calibration accuracy to avoid index error.
Relatively heavy and sensitive to environmental conditions compared to simpler instruments.
Land surveying and mapping
Construction layout and structural alignment
Topographic surveys
The horizontal circle is mounted on the vertical spindle, not the horizontal axis.
The index frame is used to support the verniers for reading circles.
A theodolite is often referred to as a 'transit' if the telescope can be revolved 360° in the vertical plane.
A is correct — The telescope is mounted on the horizontal axis (trunnion axis), allowing it to rotate in a vertical plane.
Always distinguish between the two main axes of a theodolite: the vertical axis controls horizontal angles (azimuth), while the horizontal axis controls vertical angles (inclination).