Define : 1) Bench mark 2) Datum surface 3) Line of collimation 4) Change Point

Define : 1) Bench mark 2) Datum surface 3) Line of collimation 4) Change Point 
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1 Answer

Answer :

1) Bench mark: - It is a fixed reference point of known elevation..

2)Datum surface :-It is any arbitrarily assumed level surface from which vertical distance are measured

3) Line of collimation:- It is the line joining the intersection of cross –hair on diaphragm to the optical center of the object class and its continuation up to the object.

4) Change Point:-It is the point on which the fore and back sights are taken.

 It is the point denoting the shifting of the level.
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Related questions

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Description : Define the term: (1) Level surface (2) Line of collimation

Last Answer : Level surface: It is a surface parallel to the mean spheroidal surface of the earth. It is normal to the direction of plumb line at all points. The surface of still water is an example of level ... to the optical center of object glass and its continuation. It is also called as line of sight. 

Define: i) Level Line, ii) Horizontal Line, iii) Vertical Line iv) Bench Mark.

Description : Define: i) Level Line, ii) Horizontal Line, iii) Vertical Line iv) Bench Mark. 

Last Answer : j) Level Line: It is line lying in a level surface; it is therefore, normal to the plumb line at all points. ii) Horizontal Line: It is a straight line tangential to the level line at a ... RL determined with reference to the datum line. They serve as reference points for finding RL of new points. 

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Description : Define the following terms: (i) Level surface {ii) Datum line (iii) Reduced level (iv) Axis of telescope

Last Answer : i)Level Surface : Any surface is parallel to mean spheroidal surface of earth is said to be a level surface. The water surface of still lake is also considered to be level surface. ii) ... an imaginary line passing through the optical Centre of object glass and optical Centre of the eye piece.

Define- 1. Datum 2. Change point

Description : Define- 1. Datum 2. Change point

Last Answer : 1. Datum- It is the imaginary level surface or level line from which the vertical distance of different points are measured.  2. Change point- It is the point at which both back sight and foresight readings are taken before and after shifting the level instrument. 

Define bench mark and enlist the types of bench mark.

Description : Define bench mark and enlist the types of bench mark.

Last Answer : It is fixed reference point of known or assumed elevation. It is used either as a starting point for levelling or as a check while closing. There are four kinds of bench marks. i. Great ... ) bench mark. ii. Permanent bench mark. iii. Arbitrary bench mark. iv. Temporary bench mark.

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

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

Last Answer : Bench Mark- It is fixed reference point of known or assumed elevation. Types of bench mark1. Great trignometrical survey bench mark 2. Permanent bench mark 3. Arbitrary bench mark 4. Temporary bench ... Karachi are given in catalogue formed by department. They are also known as G.T.S. Bench mark

Explain importance of Bench mark in leveling and state the types of Bench mark.

Description : Explain importance of Bench mark in leveling and state the types of Bench mark. 

Last Answer : Bench marks are fixed points or marks of known RL determined with reference to the datum line. These are very important points which serve as reference points for finding RLs of new points or for conducting ... 2. Permanent bench mark. 3. Arbitrary bench mark. 4. Temporary bench mark.

What is Level surface & Datum surface

Description : What is Level surface & Datum surface

Last Answer : Level surface : It is surface parallel to the mean spheroidal surface of the earth.  It is normal to the direction of plumb line at all points. Datum surface : It is an arbitrary level ... may be referred. Vertical distances (elevations) of the points are measured with respect to this datum.

A relatively fixed point of known elevation above datum, is called (A) Bench mark (B) Datum point (C) Reduced level (D) Reference point

Description : A relatively fixed point of known elevation above datum, is called (A) Bench mark (B) Datum point (C) Reduced level (D) Reference point

Last Answer : (A) Bench mark

Compare collimation plane method and rise and fall method of reduction of levels.

Description : Compare collimation plane method and rise and fall method of reduction of levels.

Last Answer : The comparison between collimation plane method and Rise and fall method is given below. Collimation plane method Rise and Fall method 1 1. It is rapid method as it involves few calculations. ... Arithmetic check in this method is ΣBS - ΣFS = ΣRise - ΣFall = Last RL - First RL

Differentiate between plane of collimation and rise and fall method.

Description : Differentiate between plane of collimation and rise and fall method.

Last Answer : S.N Rise and fall method Plane of collimation 1 It is slow and more tedious. It is more rapid and less tedious  2 It is laborious as it involves more calculations. It is simple ... .S.-ΣF.S=ΣRise-Σfall =Last RL-First RL Arithmetical check ΣB.S.- ΣF.S=Last RL-First RL

Explain types of bench marks.

Description : Explain types of bench marks.

Last Answer : Types of bench mark 1.Great trignometrical survey bench marka. These are the bench marks established with very high precision at regular intervals by survey of India Dept. all over the country . Their ... point. Such point should be on a permanent object so that next day it is easily identified.

Enlist various type of Bench Marks

Description : Enlist various type of Bench Marks

Last Answer : 1) Great Trigonometrical Survey Bench marks 2) Permanent Bench marks 3) Arbitrary Bench marks  4) Temporary Bench marks

Define the following terms: i) Level line ii) Bench Mark iii) Change point iv) Profile levelling

Description : Define the following terms: i) Level line ii) Bench Mark iii) Change point iv) Profile levelling

Last Answer : i) Level line - It is line lying in a level surface; it is therefore, normal to the plumb line at all points. ii) Bench Mark - These are fixed points or marks of known RL determined with ... the centerline of a proposed ditch or road or the centerline of a natural feature such as a stream bed.

Define Change point and its necessity in leveling.

Description : Define Change point and its necessity in leveling.

Last Answer : Change point : It is the point at which both backsight and foresight readings are taken before and after shifting the level instrument. Necessity of change point in leveling : It is ... observations from single station due to large area, abrupt ground level variation and unavoidable obstruction. 

Define the terms - Foresight, back sight, intermediate sight and change point.

Description : Define the terms - Foresight, back sight, intermediate sight and change point.

Last Answer : 1. Fore sight: It is the last staff reading from any set up of the leveling instrument and indicates the shifting of the instrument or end of leveling work. 2. Back sight: It is the first staff reading ... point fore sight is taken from one set up and a back sight is taken from the nest set up. 

Define : 1) Change point 2) Height of instrument.

Description : Define : 1) Change point 2) Height of instrument.

Last Answer : 1) Change point It is point on which fore and back sights are taken. 2) Height of instrument. It is the reduced level of line of collimation when the leveling instrument is properly leveled. It is ... adding the BS reading to RL of bench mark or change point on which the staff reading was taken.

Define horizontal line and vertical line.

Description : Define horizontal line and vertical line.

Last Answer : Horizontal line : A straight line tangential to the level line and perpendicular to the plumb line is called horizontal line.  Vertical line : A line perpendicular to horizontal line and coinciding plumb line is known as vertical line

Define base line and check line with neat sketch.

Description : Define base line and check line with neat sketch. 

Last Answer : 1)Base Line : The longest line running roughly through the middle of the area to be surveyed is known as base line 2) Check line: The line joining the apex of a triangle to some fixed point on the ... A line joining some fixed point on any two sides of a triangle is known as check line. 

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

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'  

Define the term – base line and check line.

Description : Define the term – base line and check line.

Last Answer : Base line: Base line is generally the longest line running roughly through the middle of the area. It is laid on a level ground as far as possible. The whole frame work is built upon this line. ... point on the opposite side or a line joining some fixed point on any two sides of the triangle.

Define: i) Mean sea level, ii) Station point.

Description : Define: i) Mean sea level, ii) Station point. 

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State the important points kept in mind while recording the staff readings in level pages with respect first reading, intermediate reading, last reading, change point, carry forward from one page to next page-Remark

Description : State the important points kept in mind while recording the staff readings in level pages with respect first reading, intermediate reading, last reading, change point, carry forward from one page to next page-Remark

Last Answer : 1) First reading is on bench mark point and should be noted in back sight(BS) column 2) Intermediate reading (IS) should be taken on the points between first and last station. 3) Last reading ... column of next page 6) Remark column should have denote First and Last RL along with change points.

State importance of Change Point in levelling

Description : State importance of Change Point in levelling

Last Answer : During the process of levelling, sometimes some staff readings are not possible. In such circumstances with respect to last staff position, the instrument is shifted to new positioning and the levelling is ... change point. It is a point on which fore sight & back sight readings are taken. 

State the important points kept in mind while recording the readings in level pages with respect first reading, intermediate readings, last reading, and change point, carry forward from one page to next page - Remarks.

Description : State the important points kept in mind while recording the readings in level pages with respect first reading, intermediate readings, last reading, and change point, carry forward from one page to next page - Remarks. 

Last Answer : The following points should be kept in mind while recording the reading in level pages. 1. The first reading should be always noted as back sight (B.S.) 2. All the intermediate readings should ... horizontal line represents only one station. 8. Readings of each station should be in one line only.

Define fly leveling and profile leveling

Description : Define fly leveling and profile leveling

Last Answer : Fly Leveling adopted to transfer bench marks from one place to other .In this leveling only FS & BS are taken.  Profile leveling:- The operation in which the object is to determine the ... known distanced apart along a given line to obtained the accurate outline of the surface of the ground 

Define: WCB and Quadrantal Bearing system

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 .

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

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

Last Answer : Orientation is the process of keeping plane table in same position as that is occupied in previous station. Methods of orientation: i) Magnetic meridian method using trough compass ii) Back ... and not by using trough compass. Therefore there is no error occurring due to local attraction.

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

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. 

Define Dip and deflection of needle.

Description : Define Dip and deflection of needle.

Last Answer : Dip of the magnetic needle: It is the upward or downward movement of magnetic needle in vertical plane due to earth's gravitational force is known as dip of needle. Deflection of needle : ... west direction, that horizontal angle between magnetic and true north is said to be declination of needle.

Define local attraction. State two causes of local attraction.

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

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. Causes of local attraction : 1. Iron ... structure 2. Electric cable line 3. High voltage current 4. Bunch of key 5. Steel Tape 

Define : i) Traversing ii) Magnetic Meridian

Description : Define : i) Traversing ii) Magnetic Meridian

Last Answer : i) Traversing : Traversing is the series of survey lines connecting successive established traverse stations along the route of survey  ii) Magnetic Meridian : The direction indicated by ... and properly balanced Magnetic needle unaffected by local attractive force is called magnetic meridian.

Define true bearing and magnetic 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.

Define surveying.

Description : Define surveying.

Last Answer : Surveying- It is branch of civil engineering in which relative positions of ground points are determined by taking linear and angular measurement.

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

Define surveying & state its objectives

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.

Define orientation and principle of plane tabling.

Description : Define orientation and principle of plane tabling. 

Last Answer : Orientation: The orientation of plane table means keeping the plane table at all stations parallel to the position it occupied at first station. Principles of plane table survey: 1. The rays drawn from ... same as that of previous station i.e. orientation should be done at each changed station.  

Define: i) W.C.B. ii) Reduced 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 

Define: i) Open Traverse ii) Closed Traverse.

Description : Define: i) Open Traverse ii) Closed Traverse. 

Last Answer : i) Open traverse: When the first and last survey lines does not meets at common point and hence does not form a closed polygon, then it is said to be open traverse.  ii) Closed Traverse: When last and first survey stations meet at common point, traverse is called as closed traverse.

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

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.

State any four types of offsets and define them.

Description : State any four types of offsets and define them. 

Last Answer : i) Long offset: If length of offset more than 15 m. ii) Short offset: If length of offset less than 15 m. iii) Perpendicular offset: Offset taken perpendicular to chain line. iv) Oblique offset: Offset not taken perpendicular to chain line.

Define the following: (i) Height of instrument (i) Back sight (iii) Fore sight (iv) Axis of bubble tube

Description : Define the following: (i) Height of instrument (i) Back sight (iii) Fore sight (iv) Axis of bubble tube

Last Answer : i. Height of instrument: It is the reduced level of line of collimation when the leveling instrument is properly leveled. It is obtained by adding the BS reading to RL of bench mark or change point on which the ... when the bubble is at the center of its run i.e. at middle point of the tube.

Define Local attraction.

Description : Define Local attraction.

Last Answer : Local attraction – when magnetic needle does not remain in N-S direction due to effect of magnetic substances present around the compass, such error at station is known as local attraction. 

Define: (i) Long offset (ii) Short offset

Description : Define: (i) Long offset (ii) Short offset

Last Answer : i. Long offset: The offset whose length is more than 15 m. ii. Short offset: The offset whose length is less than or equal to 15 m.

Define: (i) True meridian (ii) Magnetic meridian

Description : Define: (i) True meridian (ii) Magnetic meridian

Last Answer : i. True meridian: It is line of intersection of plane passing through North Pole, South Pole and point under consideration.  ii. Magnetic meridian: Magnetic meridian at point is direction shown by freely suspended magnetic needle at that point.

Define Ranging. State types of ranging.

Description : Define Ranging. State types of ranging.

Last Answer : Ranging: It is process of locating points on ground along straight line. Types of ranging: 1. Direct ranging. 2. Indirect ranging

Define leveling.

Description : Define leveling.

Last Answer : Levelling is an ‘art of determining relative heights or elevations of different points on the earth’s surface so that the same may be represented on a plan or map’. It is essentially a process dealing with the measurements in vertical plane.

Define 1)Ranging 2)Chaining

Description : Define 1)Ranging 2)Chaining

Last Answer : 1) Ranging The method of establishing intermediate points on a straight line between the two fixed points is known as ranging. 2)Chaining The method of measuring the distance with the chain or tape is called as Chaining.

Draw sketch and write the procedure for setting offset to the left or right side of suvey line with open cross-staff.

Description : Draw sketch and write the procedure for setting offset to the left or right side of suvey line with open cross-staff.

Last Answer : Procedure for setting offset with open cross staff : 1. Keep the ranging rods at point P(fixed on survey line) and at point A1 approximately. 2. The cross staff with stadia rod is fixed ... can be fixed and perpendicular offset AB is said to be set to given survey line PQ in left side.

Defines the terms : i) Survey Station ii) Survey Line iii)Offset iv)Triangulation

Description : Defines the terms : i) Survey Station ii) Survey Line iii)Offset iv)Triangulation 

Last Answer : i) Survey Station : It is the point on ground from which various observations are taken around it. ii) Survey Line : It is the straight line joining two successive survey stations ... iv)Triangulation : The frame work consist of number of connected well conditional triangle is called Triangulation.