Describe quadrantal bearing system. State the purpose it is used. 

1 Answer

Answer :

Quadrantal Bearing –

1. The magnetic bearing of line measured clockwise or anticlockwise from north or south pole whichever is nearer.

2. These bearings are also called as reduced bearings.

3. These are observed by surveyors compass

4. Its value is between 0 0 to 900.

5. It consists of four quadrants - N-E, S-E, S-W, N-W.


Purposes

1. It is used to measure bearing of survey lines in a closed traverse.

2. It is used to calculate back bearing for respective quadrants.

Related questions

Description : Define: WCB and Quadrantal Bearing system

Last Answer : Ans.: 1)WCB:-In this system the bearing of a line is always measured clockwise for the north point of the reference meridian towards the line round the circle the angle thus measured is called ... the bearing of a line is measured clockwise from the north point or south point whichever is nearest .

Description : In quadrantal bearing system, back bearing of a line may be obtained from its forward bearing, by (A) Adding 180°, if the given bearing is less than 180° (B) Subtracting 180°, if the given bearing, is more ... cardinal points, i.e. substituting N for S and E for W and vice-versa (D) None of these

Last Answer : (C) Changing the cardinal points, i.e. substituting N for S and E for W and vice-versa

Description : Define the terms i) Fore Bearing, ii) Open traverse, iii) Closing error, iv) Reduced bearing

Last Answer : i) Fore bearing : The bearing observed in the direction of progress of survey in clockwise manner is called fore bearing  ii) Open traverse : When the first and last survey lines does ... north or south direction in clockwise or anticlockwise manner is known as reduced or quadrantal bearing. 

Description : Define true bearing and magnetic bearing.

Last Answer : 1. True bearing – (i) The angle between true meridian or geographical north and any line known as true bearing. 2.Magnetic bearing-(i)The angle between magnetic meridian and any line is known as magnetic bearing.

Description : Define- 1. Whole circle bearing 2. Reduced bearing 3. Fore bearing 4. Back bearing

Last Answer : 1.Whole circle bearing-  The bearing measures only in the clockwise direction from meridian or north direction is known as whole circle bearing. 2.Reduced bearing  The bearing measures with ... bearing  The bearing observed in the direction of opposite of survey is called fore bearing. 

Description : Define: i) W.C.B. ii) Reduced Bearing

Last Answer : i)Whole circle bearing: The bearing measures only in the clockwise direction from meridian or north direction is known as whole circle bearing.   ii) Reduced bearing: The bearing measured ... north or south direction in clockwise or anticlockwise manner is known as reduced or quadrant bearing 

Description : Define ‘ Fore bearing ’ & ‘ back bearing ’ of line with a neat sketch

Last Answer : Fore bearing : The bearing of line observed in the direction of progress of survey is called fore bearing of the line. Bearing of line AB is observed at A' towards B' is called as fore bearing of the line ... The bearing observed at B' towards A' is called as back bearing of the line AB'  

Description : With neat sketch, write the procedure of measurement of fore bearing with compass.

Last Answer : For measuring fore bearing of line AB, i) Place the compass over station A, center and level it.  ii) Looking through eye slit towards object vane, bisect the ranging rod at station ... which coincides with horse hair at observer end. The observed reading is the fore bearing of line AB

Description : Define the terms - dip of needle, magnetic bearing, fore bearing and back bearing.

Last Answer : Dip of needle: It is downward inclination or small angle made by freely suspended magnetic needle with the horizontal. Magnetic bearing: Magnetic bearing of a survey line is the horizontal angle ... of line measured in backward direction or opposite direction of survey, is known as back bearing.

Description : Find the back bearing of the following lines having fore bearing as given below: (i) PQ = N 55° 0' E (ii) EF == 280° 0' (iii) CD = S 58° 30' W (iv) OM= 180° 0'

Last Answer : i) F.B OF PQ = N 55°0 ’ E  B.B Of PQ = S 55°0 ’W  ii) F.B. Of EF = 280°0 ’   B.B OF EF = F.B -180°= 280°0 ’ -180° = 100°0 ’  iii) F.B OF CD = S 58°30’W  B.B OF CD = N 58°30’ E  iv) F.B OF GH = 180°  B.B OF GH = F.B -180°=180°-180°= 0°

Description : Differentiate between reduced bearing and whole circle bearing

Last Answer : Quadrantal Bearing/Reduced Bearing Whole Circle Bearing The horizontal angle made by a line with the magnetic north or south (whichever is closer from the line) in the eastward or westward direction ... from 0° to 90°  The value of the whole circle bearing varies from 0° to 360° 

Description : Whole circle bearing of a line is preferred to a quadrantal bearing merely because (A) Bearing is not completely specified by an angle (B) Bearing is completely specified by an angle ... different in different quadrants (D) Its Trigonometrical values may be extracted from ordinary tables easily

Last Answer : (B) Bearing is completely specified by an angle

Description : State and describe the types of offsets. 

Last Answer : 1. Perpendicular offset- When the offset is taken at 900 to the survey line, then it is known as perpendicular offset. 2. Oblique offset- When the offset is taken at an angle other than 900 ( ... when offset is set by swinging chain or tape to survey line, such formed offset is called Swing offset.

Description : Describe with neat sketch, the optical square and explain its principle.

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Description : Describe stepping method of chaining on sloping ground.

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Description : Describe the procedure of indirect ranging.

Last Answer : Procedure of indirect ranging. 1. If two stations i.e. A and B are not visible, then two intermediate points M1 and N1 are selected such that both stations will be intervisible from it. 2. ... continued till final points M and N are in line with AB, thus, ranging is said to be completed.

Description : Describe method of measuring distances on ground using chain and arrows.

Last Answer : Method of measuring distances on ground. 1. Mark the position of survey stations whose distance is to be measured using wooden peg. (say A and B) 2. now, ranging is done if distance ... station B. Thus total horizontal distance will be equal to addition of distances measured of each parts.

Description : Describe instrumental errors in leveling.

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Description : Describe in brief errors in levelling. 

Last Answer : The sources of error in levelling are as below 1) Instrumental errors: Error due to imperfect adjustment, Sluggish bubble, Faulty Focusing tube, Erroneous leveling staff. 2) Personal errors: ... length. Use umbrella to shelter the instrument, use sun shade, avoid levelling work during wind. 

Description : Describe in brief profile levelling.

Last Answer : The operation of taking levels along the center line of any alignment at regular interval is called longitudinal or profile levelling. Along the alignment, spots are marked at regular interval ... the points are plotted against their chainage to obtain ground profile along the alignment.

Description : Describe in brief errors in plane table survey.

Last Answer : 1) The board not being horizontal. 2) The table not being accurately centered. 3) The table not being Correctly oriented. 4) The objects not being sited accurately. 5) The alidade not being ... through the station point. 7) Inaccuracy in plotting. 8) The expansion and contraction of the paper.

Description : Describe in brief resection method of plane table surveying.

Last Answer : This method is used for establishing the instrument stations only. After fixing the stations, details are located either by radiation or intersection. The characteristic feature of resection is that the point ... of resection are (1)The Two Point Problem, and (2)Three Point Problem.

Description : Describe in brief errors in compass survey.

Last Answer : Errors in Compass Surveying. The errors are classified as: 1. Instrumental errors. 2. Personal or Observational errors. 3. Errors due to External Influences (Natural errors etc.).  (1 ... in magnetic declination. (iii) Local attraction due to proximity of electric lines, steel structures etc.

Description : Describe in brief obstacles in chaining.

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Description : Describe in brief process of chaining on sloping ground.

Last Answer : In direct method which is also known as stepping method horizontal distance is directly measured as shown in fig. Horizontal distance between A and B is required to be measured. Procedure: i) A ... iii) The next step start from the C and the method is continued till point B reached. 

Description : Describe in brief primary classification of surveying

Last Answer : Primary Classification Geodetic Survey The geodetic surveying is that type of surveying which takes into account the curvature of earth's surface. It is generally adopted for large area (more than ... large scale such as Bridges, Dams, Location and Construction of canals, highways, railways etc.

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Description : State the situation where plane table is suitable. 

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Description : State advantages of plane table survey one each with respect to booking and suitability

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Description : State two advantages of telescopic alidade over simple alidade.

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Description : Define orientation. State two methods of orientation. Which method is most accurate and why? 

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Description : State temporary adjustments of prismatic compass

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Description : State four instruments used for setting offsets.

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Description : Define local attraction. State two causes of local attraction.

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Description : What is bench mark? State the types of bench mark and explain any one type.

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Description : State any two uses of survey.

Last Answer : Survey is useful for following: 1. To prepare a map or plan of the surveyed area for attaching it to legal documents. 2. To plot control points of boundries of locality 3. To determine ... . 5. To decide suitable gradient and camber of road depending on equal volume of cutting and filling.

Description : What is meant by local attraction? How will you suspect local attraction at the field ? state its effect on included angle.

Last Answer : Local attraction: It is the deviation or deflection of magnetic needle from its normal position under influence of external magnetic forces is called as local attraction. Suspect of local attraction ... The needle is affected by local attraction therefore it does not give a corrected angle

Description : State any four sources of errors in compass survey 

Last Answer : Following are the sources of errors in compass survey1. Instrumental survey-  a. Needle may not be perfectly straight and might not be balanced properly over the station.  b. Graduations of the rings ... substances near the station.  b. Magnetic field may vary on account of some natural causes. 

Description : State fundamental axis of dumpy level and give their relationship 

Last Answer : Fundamental axes of dumpy level : i) The vertical axis ii) The axis of bubble tube iii) The line of collimation iv) The axis of the telescope Relations of Fundamental axes : i) The ... parallel to the axis of the bubble tube. iii) Axis of telescope and line of collimation should coincide. 

Description : State the use of following- 1. Arrow 2. Wooden peg

Last Answer : 1. Arrow Arrows are used for counting the number of chains while measuring a chain line. 2. Wooden peg Pegs are used for fixing the instrument station on the ground permanent marking

Description : Define surveying & state its objectives

Last Answer : Surveying- It is branch of civil engineering in which relative positions of ground points are determined by taking linear and angular measurement. Objectives: 1. To determine the relative positions of ... quantities 4. To prepare a topographical map showing details of hills, valleys and rivers.

Description : State the important point to be remembered while doing profile leveling.

Last Answer : 1. The chainage of staff stations are continuous from beginning to the end of the section line. 2. Readings of B.S. and F.S. should be taken very accurately with the bubble exactly in ... their width or by offset. 5)All the temporary adjustments at all instrument position shall carefully be done. 

Description : State different types of leveling. Explain any one in brief.

Last Answer : Types of Levelling  1. Simple Levelling.  2. Differential Levelling.  3. Fly Levelling.  4. Longitudinal or profile leveling.  5. Cross-Section Levelling.  6. Check Levelling.  1. ... B are taken. The difference of these readings gives the difference of level between A and B. 

Description : State different methods of plotting compass traverse. 

Last Answer : Methods of plotting compass traverse are: 1. By parallel meridian through each station. 2. By included angle. 3. By paper protractor. 4. By rectangular co-ordinates. 5. Plotting by tangents. 6. Plotting by chords.