Theodolite Traversing Lecture 26

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What is the main purpose of a theodolite?

Measuring horizontal distance
Calculating area of land
Measuring angles in horizontal and vertical planes (correct)
Determining the volume of a structure

Which of the following is NOT a use of a theodolite?

Measuring magnetic bearing
Calculating area of land (correct)
Finding vertical height of an object
Measuring deflection angle

What is the function of the vertical circle in a theodolite?

Measure vertical angles (correct)
Measure horizontal angles
Eliminate parallax
Focus the telescope

Which type of theodolite is not mentioned in the text?

Digital Theodolite (B) Signup and view all the answers

What is the least count of a theodolite used for measuring angles up to 10'' or 20''?

$1''$ (B) Signup and view all the answers

What part of a theodolite is used to find the difference of elevation between various points?

Vertical Scale (D) Signup and view all the answers

What is used to hold the telescope at a particular vertical angle?

Vertical Clamp (D) Signup and view all the answers

Which part of the instrument is responsible for defining the horizontal direction in which the telescope is sighted?

Horizontal Scale (B) Signup and view all the answers

What is necessary for the upper plate to be perpendicular to and parallel to?

Alidade Axis and Trunnion Axis (D) Signup and view all the answers

What is used to adjust and level the upper plate of the instrument?

Three-foot screws (A) Signup and view all the answers

Which part of the instrument must be used at the start of a sequence of horizontal angle measurements to set the first reading to zero?

Upper Horizontal Clamp (C) Signup and view all the answers

What component carries two Verniers and clipping screws?

Index Bar (B) Signup and view all the answers

What is used for levelling particularly when taking vertical angle observations?

Plumb Bob (D) Signup and view all the answers

What is located on one of the standards and requires illumination?

Vertical Circle (B) Signup and view all the answers

What is provided to clamp the horizontal circle to the lower plate?

Lower Horizontal Clamp (A) Signup and view all the answers

Which part of the instrument reflects maximum light onto the vertical and horizontal circles?

Circular Mirrors (D) Signup and view all the answers

What is the method used to measure a horizontal angle to a finer degree of accuracy?

Method of repetition (D) Signup and view all the answers

How are vertical angles measured with a theodolite?

By bisecting P and locking the clamp (A) Signup and view all the answers

What is the purpose of a traverse in surveying?

To establish boundaries in property surveys (A) Signup and view all the answers

How is the average horizontal angle calculated in the method of repetition?

By dividing the final reading by the number of repetitions (D) Signup and view all the answers

What is the technique used when a number of angles are to be measured from a station?

Method of reiteration (A) Signup and view all the answers

How does the Included Angle method work in surveying?

By observing and measuring angles incrementally at each point (A) Signup and view all the answers

What is done at each point where a traverse changes direction?

An angular measurement is taken using a theodolite (D) Signup and view all the answers

'Angle of elevations' are noted as ______ angles.

+ve (D) Signup and view all the answers

'Angle of depression' are noted as ______ angles.

-ve (A) Signup and view all the answers

What does the term 'changing face' refer to?

Bringing the vertical circle from one side of the observer to the other (B) Signup and view all the answers

What is the purpose of 'transiting' when using a theodolite?

To rotate the telescope in a vertical plane through 180 degrees (B) Signup and view all the answers

What is 'centering' in relation to the theodolite?

Setting the theodolite exactly over a marked station with a plumb bob (C) Signup and view all the answers

What is meant by 'line of collimation'?

Imaginary line passing through the optical center of objective glass and its continuation (B) Signup and view all the answers

When should Vernier A be read to get the desired horizontal angle?

When Vernier B reads 180° (D) Signup and view all the answers

In which case is 'left swing' performed with a theodolite?

When turning the telescope anticlockwise (A) Signup and view all the answers

What is 'temporary adjustment' in the context of using a theodolite?

The setting of the instrument over a station at the time of taking any observation (D) Signup and view all the answers

'Face right' in the context of using a theodolite means:

'Vertical circle on the right of observer when taking reading' (B) Signup and view all the answers

'Horizontal axis' on a telescope refers to:

'Axis of rotation of telescope in horizontal plane' (D) Signup and view all the answers

'Swinging the telescope' involves:

'Turning telescope in horizontal plane' (D) Signup and view all the answers

What is the formula to calculate interior angles of a traverse?

(2n-4) x 900 (D) Signup and view all the answers

How is the bearing of a line PQ measured in the text?

By reading Vernier A when bisecting signal at Q (C) Signup and view all the answers

What is the purpose of balancing a traverse?

To adjust for observational errors in a closed traverse (A) Signup and view all the answers

What does the term 'closing error' refer to in a traverse?

The distance between the originating station and computed position (A) Signup and view all the answers

In Bowditch's method, what are CD and CL used for?

Correct the departure and latitude of a traverse line (C) Signup and view all the answers

Which component of a line does 'Latitude' refer to in surveying?

North-south component (D) Signup and view all the answers

What is Transit Rule commonly used for in surveying?

To balance a traverse when angular measurements are more precise (B) Signup and view all the answers

What are the conditions that must be satisfied in a closed traverse regarding Latitude and Departure?

$ ext{Σ Departure} = ext{ΣD} = 0$ and $ ext{Σ Latitude} = ext{ΣL} = 0$ (C) Signup and view all the answers

'Gal's Traverse Table' typically deals with measuring what in the field?

Lengths and angles of a closed traverse (A) Signup and view all the answers

What is the purpose of Gale's Traverse Table?

To systematically record field data and computations for traverse adjustment (C) Signup and view all the answers

In the traverse adjustment process, what is done if the sum of all interior angles does not satisfy the geometric conditions?

Adjust the discrepancy and enter corrections in a specific column (A) Signup and view all the answers

How are errors distributed to all sides of a traverse when balancing the closing error graphically?

Errors are distributed proportionally to the distance from the initial station (B) Signup and view all the answers

What is the significance of marking traverse stations on a horizontal line during graphical balancing?

To represent the perimeter of the plotted traverse (A) Signup and view all the answers

Which column in Gale's Traverse Table is used to enter corrections for discrepancies?

Column 5 (B) Signup and view all the answers

What conditions need to be satisfied by the sum of exterior angles in a traverse?

(2n + 4) right angles (D) Signup and view all the answers

What is used to compute independent coordinates of points in a traverse?

'Known or assumed independent coordinates' (C) Signup and view all the answers

In graphical balancing, what does shifting equal to Qo Qa represent?

'Errors at station Qo' (D) Signup and view all the answers