83 Questions
What is the main purpose of a theodolite?
Measuring vertical and horizontal angles
Which part of a theodolite is used to measure the angle between the line of sight and the horizontal?
Vertical Scale
What is the maximum angle that can be accurately measured by a theodolite?
$20^{ c{''}}$
Which type of theodolite is mounted within one of the standards with a full 360° vertical scale?
Transit Theodolite
What is the main feature of a telescope in a theodolite?
Internal Focussing
Which of the following is NOT among the uses of a theodolite?
Calculating area under a curve
What is the term for turning the telescope about its horizontal axis in a vertical plane through 180 degrees?
Transiting
Which imaginary line passes through the optical center of the objective glass and its continuation?
Line of collimation
What is the operation known as bringing the vertical circle from one side of the observer to the other?
Changing face
What is the setting of a theodolite over a station at the time of taking any observation called?
Temporary adjustment
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
What is an important feature that allows the telescope to rotate on its trunnion axis in a vertical frame?
'A' shape
Which term refers to turning the telescope in a horizontal plane, specifically clockwise?
'Right swing'
What is an imaginary line tangential to the longitudinal curve of a bubble tube at its middle point called?
'Bubble tube' axis
In measuring horizontal angles, what action results in changing the face left position?
'Transiting' the telescope to the left
'Temporary adjustment' of a theodolite involves which process among these?
'Centering', leveling, and focusing
What is used to center the instrument exactly over a station mark?
Plumb bob
What is used to define the horizontal direction in which the telescope is sighted?
Horizontal scale
Which component is responsible for holding the telescope at a particular vertical angle?
Vertical clamp
What is necessary for the upper plate to be before using the instrument?
Levelled
Which part of the instrument is rigidly attached to the tripod mounting assembly?
Lower plate
What is adjusted to observe a precise tube bubble known as the plate bubble?
Three-foot screws
Which component should be perpendicular to the alidade axis?
Upper plate
What is used to transit the telescope when clamped at a particular vertical angle?
Vertical tangent screw
What is centered on the horizontal axis of the telescope in front of the vertical axis?
T-frame
What must be adjusted using three-foot screws before using the instrument?
Upper plate
What method is used to measure a horizontal angle to a finer degree of accuracy?
Method of repetition
In the process of measuring vertical angles, what is kept parallel to any two leveling screws?
Altitude level
What is the purpose of a traverse in land surveying?
To establish boundaries
In the Included Angle method for closed traverse, what is observed at the 1st station A?
Bearing of line AB
How are vertical angles noted in land surveying?
+ve and 've angles
What is done with the Vernier during each repetition in the method of repetition?
Remains clamped
When carrying out the leveling process for measuring vertical angles, what is brought to center by operating two leveling screws?
've angles
What does the average horizontal angle calculation involve in the method of repetition?
Dividing the final reading by the number of repetitions
'The points defining the ends of traverse lines' are known as:
'traverse stations'
'Property surveys to locate or establish boundaries' is one purpose of:
'Traverse in land surveying'
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
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
Which column in Gale's Traverse Table would corrections be entered into according to the text?
Column 5
Why are corrections applied graphically to the positions of stations in a traverse according to the text?
To balance the closing error graphically
What does a horizontal line Po P' represent in a graphical balancing according to the text?
The perimeter of the plotted traverse
How are corrections distributed to all sides of a traverse in graphical balancing according to the text?
They are proportional to station distances
What is the purpose of calculating independent coordinates in a traverse according to the text?
To find coordinates of points from known values
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
What is the significance of summing up latitudes and departures in a traverse according to the text?
To calculate corrections for all sides
Why are corrections applied directly proportional to station distance in graphical balancing according to the text?
To balance the traverse efficiently
What is the formula for calculating the interior angles of a traverse with 'n' sides?
(2n-4) x 900
In balancing a traverse, what is the closing error defined as?
The difference between the actual position and the computed position of a station
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
What does latitude represent in relation to a traverse line?
North-South component
When balancing a traverse using Bowditch's method, what does 'CD' represent?
Correction to departure of the line
Which condition must be met in a closed traverse in terms of latitude and departure?
Σ Departure - ΣD = 0, Σ Latitude - ΣL = 0
What is the primary purpose of Bowditch's method in balancing a traverse?
Adjust linear errors based on length proportionality
In a traverse, what does 'DT' represent when balancing using the Transit rule?
|Sum of all departures|
'Gal's Traverse Table' in fieldwork primarily focuses on measuring:
Inward angles and distances of open traverses
'Transit rule' is particularly suitable for which type of surveying situation?
'Transit rule' works well when angular measurements are more precise than linear measurements
What is the purpose of the filtration process described in the text?
To remove bacteria and fine suspended particles
Which mechanism of filtration is due to the force of gravity and settling velocity of particles?
Sedimentation
For what type of particles does interception play a role in the filtration process?
Large particles
What type of particles does Brownian diffusion primarily affect during filtration?
Viruses
What material is commonly used as filter media in the filtration process described in the text?
Sand
How is the size of sand used as filter media typically expressed?
'Effective size'
What is the method of cleaning for a Rapid Sand Filter (RSF)?
Agitating and backwashing sand
What is the Carman-Kozeny equation used to calculate in the context of filter operation?
Head loss in the filter
When should a Rapid Sand Filter be backwashed?
When floc starts breaking through the filter
What causes the phenomenon known as 'Air Binding' in a filter?
Frictional resistance by filter media
What happens if a Rapid Sand Filter runs for longer periods without backwashing?
Media compaction
What does the uniformity coefficient measure?
Particle size distribution
What is the primary function of a 'Schmutzdecke' in slow sand filtration?
Providing habitat for microorganisms
Which type of filter captures particles throughout the bed and is cleaned by backwashing water through the bed?
Rapid sand filter
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
What property of filter sand differs between slow sand filtration and rapid sand filtration?
Effective size and uniformity coefficient
Why is anthrafilt sometimes used instead of sand as filter media?
To provide a cheaper alternative
What is the significance of the 'Schmutzdecke' layer in slow sand filtration?
It retains particles smaller than sand grains
How are impurities primarily removed in slow sand filtration during the first few days of operation?
'Schmutzdecke' formation
'Multimedia filters' consist of two or more layers of different granular materials for what purpose?
To provide versatile particle collection
What is the ratio that defines the uniformity coefficient?
(D60/ D10)
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
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
What is the maximum recommended loss of head in a Rapid Sand filter?
2 to 5 m
What is the recommended velocity of flow in the manifold for washwater in a Rapid Sand filter?
1.8 m/s
In designing a rapid sand filter, what is the total area of lateral perforations recommended per lateral?
17.5 cm
What is the recommended spacing of holes in the lateral pipes of a rapid sand filter?
15 cm c/c
Learn about the theodolite, a precision instrument for measuring angles in horizontal and vertical planes. Understand its uses in surveying applications and specialized purposes. Explore how the theodolite is used for accurate measurements of horizontal and vertical angles.
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