Lecture 26: Theodolite Traversing

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What is the main purpose of a theodolite?

Calculating the area of a land parcel

Determining the elevation of a single point

Measuring vertical and horizontal angles (correct)

Measuring the distance between two points

Which part of a theodolite is used to measure the angle between the line of sight and the horizontal?

Compass

Vertical Scale (correct)

Alidade

Plumb Bob

What is the maximum angle that can be accurately measured by a theodolite?

$30^{ c{''}}$

$10^{ c{''}}$

$5^{ c{''}}$

$20^{ c{''}}$ (correct)

Which type of theodolite is mounted within one of the standards with a full 360° vertical scale?

Transit Theodolite Signup and view all the answers

What is the main feature of a telescope in a theodolite?

Internal Focussing Signup and view all the answers

Which of the following is NOT among the uses of a theodolite?

Calculating area under a curve Signup and view all the answers

What is the term for turning the telescope about its horizontal axis in a vertical plane through 180 degrees?

Transiting Signup and view all the answers

Which imaginary line passes through the optical center of the objective glass and its continuation?

Line of collimation Signup and view all the answers

What is the operation known as bringing the vertical circle from one side of the observer to the other?

Changing face Signup and view all the answers

What is the setting of a theodolite over a station at the time of taking any observation called?

Temporary adjustment Signup and view all the answers

What is the English letter form that supports the frames for the telescope to rotate on its trunnion axis in a vertical frame?

A-frame Signup and view all the answers

What is an important feature that allows the telescope to rotate on its trunnion axis in a vertical frame?

'A' shape Signup and view all the answers

Which term refers to turning the telescope in a horizontal plane, specifically clockwise?

'Right swing' Signup and view all the answers

What is an imaginary line tangential to the longitudinal curve of a bubble tube at its middle point called?

'Bubble tube' axis Signup and view all the answers

In measuring horizontal angles, what action results in changing the face left position?

'Transiting' the telescope to the left Signup and view all the answers

'Temporary adjustment' of a theodolite involves which process among these?

'Centering', leveling, and focusing Signup and view all the answers

What is used to center the instrument exactly over a station mark?

Plumb bob Signup and view all the answers

What is used to define the horizontal direction in which the telescope is sighted?

Horizontal scale Signup and view all the answers

Which component is responsible for holding the telescope at a particular vertical angle?

Vertical clamp Signup and view all the answers

What is necessary for the upper plate to be before using the instrument?

Levelled Signup and view all the answers

Which part of the instrument is rigidly attached to the tripod mounting assembly?

Lower plate Signup and view all the answers

What is adjusted to observe a precise tube bubble known as the plate bubble?

Three-foot screws Signup and view all the answers

Which component should be perpendicular to the alidade axis?

Upper plate Signup and view all the answers

What is used to transit the telescope when clamped at a particular vertical angle?

Vertical tangent screw Signup and view all the answers

What is centered on the horizontal axis of the telescope in front of the vertical axis?

T-frame Signup and view all the answers

What must be adjusted using three-foot screws before using the instrument?

Upper plate Signup and view all the answers

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

Method of repetition Signup and view all the answers

In the process of measuring vertical angles, what is kept parallel to any two leveling screws?

Altitude level Signup and view all the answers

What is the purpose of a traverse in land surveying?

To establish boundaries Signup and view all the answers

In the Included Angle method for closed traverse, what is observed at the 1st station A?

Bearing of line AB Signup and view all the answers

How are vertical angles noted in land surveying?

+ve and 've angles Signup and view all the answers

What is done with the Vernier during each repetition in the method of repetition?

Remains clamped Signup and view all the answers

When carrying out the leveling process for measuring vertical angles, what is brought to center by operating two leveling screws?

've angles Signup and view all the answers

What does the average horizontal angle calculation involve in the method of repetition?

Dividing the final reading by the number of repetitions Signup and view all the answers

'The points defining the ends of traverse lines' are known as:

'traverse stations' Signup and view all the answers

'Property surveys to locate or establish boundaries' is one purpose of:

'Traverse in land surveying' Signup and view all the answers

What is the purpose of summing up all the angles in a traverse according to the text?

To ensure the sum of interior angles equals (2n - 4) right angles Signup and view all the answers

What is the purpose of converting whole circle bearings to reduced bearings in a traverse according to the text?

To simplify plotting on a graphical balance Signup and view all the answers

Which column in Gale's Traverse Table would corrections be entered into according to the text?

Column 5 Signup and view all the answers

Why are corrections applied graphically to the positions of stations in a traverse according to the text?

To balance the closing error graphically Signup and view all the answers

What does a horizontal line Po P' represent in a graphical balancing according to the text?

The perimeter of the plotted traverse Signup and view all the answers

How are corrections distributed to all sides of a traverse in graphical balancing according to the text?

They are proportional to station distances Signup and view all the answers

What is the purpose of calculating independent coordinates in a traverse according to the text?

To find coordinates of points from known values Signup and view all the answers

Why is Transit rule or Bowditch's rule applied in calculating corrections in a traverse according to the text?

To balance the closing error numerically Signup and view all the answers

What is the significance of summing up latitudes and departures in a traverse according to the text?

To calculate corrections for all sides Signup and view all the answers

Why are corrections applied directly proportional to station distance in graphical balancing according to the text?

To balance the traverse efficiently Signup and view all the answers

What is the formula for calculating the interior angles of a traverse with 'n' sides?

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

In balancing a traverse, what is the closing error defined as?

The difference between the actual position and the computed position of a station Signup and view all the answers

Which method is generally used for adjusting the closing error in a traverse when linear errors are proportional to √l and angular errors are proportional to 1/√l?

Bowditch's method Signup and view all the answers

What does latitude represent in relation to a traverse line?

North-South component Signup and view all the answers

When balancing a traverse using Bowditch's method, what does 'CD' represent?

Correction to departure of the line Signup and view all the answers

Which condition must be met in a closed traverse in terms of latitude and departure?

Σ Departure - ΣD = 0, Σ Latitude - ΣL = 0 Signup and view all the answers

What is the primary purpose of Bowditch's method in balancing a traverse?

Adjust linear errors based on length proportionality Signup and view all the answers

In a traverse, what does 'DT' represent when balancing using the Transit rule?

|Sum of all departures| Signup and view all the answers

'Gal's Traverse Table' in fieldwork primarily focuses on measuring:

Inward angles and distances of open traverses Signup and view all the answers

'Transit rule' is particularly suitable for which type of surveying situation?

'Transit rule' works well when angular measurements are more precise than linear measurements Signup and view all the answers

What is the purpose of the filtration process described in the text?

To remove bacteria and fine suspended particles Signup and view all the answers

Which mechanism of filtration is due to the force of gravity and settling velocity of particles?

Sedimentation Signup and view all the answers

For what type of particles does interception play a role in the filtration process?

Large particles Signup and view all the answers

What type of particles does Brownian diffusion primarily affect during filtration?

Viruses Signup and view all the answers

What material is commonly used as filter media in the filtration process described in the text?

Sand Signup and view all the answers

How is the size of sand used as filter media typically expressed?

'Effective size' Signup and view all the answers

What is the method of cleaning for a Rapid Sand Filter (RSF)?

Agitating and backwashing sand Signup and view all the answers

What is the Carman-Kozeny equation used to calculate in the context of filter operation?

Head loss in the filter Signup and view all the answers

When should a Rapid Sand Filter be backwashed?

When floc starts breaking through the filter Signup and view all the answers

What causes the phenomenon known as 'Air Binding' in a filter?

Frictional resistance by filter media Signup and view all the answers

What happens if a Rapid Sand Filter runs for longer periods without backwashing?

Media compaction Signup and view all the answers

What does the uniformity coefficient measure?

Particle size distribution Signup and view all the answers

What is the primary function of a 'Schmutzdecke' in slow sand filtration?

Providing habitat for microorganisms Signup and view all the answers

Which type of filter captures particles throughout the bed and is cleaned by backwashing water through the bed?

Rapid sand filter Signup and view all the answers

What is the primary difference between slow sand filters (SSF) and rapid sand filters (RSF) regarding the rate of filtration?

RSF filters faster than SSF Signup and view all the answers

What property of filter sand differs between slow sand filtration and rapid sand filtration?

Effective size and uniformity coefficient Signup and view all the answers

Why is anthrafilt sometimes used instead of sand as filter media?

To provide a cheaper alternative Signup and view all the answers

What is the significance of the 'Schmutzdecke' layer in slow sand filtration?

It retains particles smaller than sand grains Signup and view all the answers

How are impurities primarily removed in slow sand filtration during the first few days of operation?

'Schmutzdecke' formation Signup and view all the answers

'Multimedia filters' consist of two or more layers of different granular materials for what purpose?

To provide versatile particle collection Signup and view all the answers

What is the ratio that defines the uniformity coefficient?

(D60/ D10) Signup and view all the answers

What is one of the remedial measures suggested to prevent cracking of filters and formation of mud balls?

Breaking the top fine mud layer with rakes Signup and view all the answers

In the standard design practice of a Rapid Sand filter, what is the maximum recommended spacing for holes in the filter?

6 mm at 7.5 cm c/c Signup and view all the answers

What is the maximum recommended loss of head in a Rapid Sand filter?

2 to 5 m Signup and view all the answers

What is the recommended velocity of flow in the manifold for washwater in a Rapid Sand filter?

1.8 m/s Signup and view all the answers

In designing a rapid sand filter, what is the total area of lateral perforations recommended per lateral?

17.5 cm Signup and view all the answers

What is the recommended spacing of holes in the lateral pipes of a rapid sand filter?

15 cm c/c Signup and view all the answers