State temporary adjustments of prismatic compass

State temporary adjustments of prismatic compass
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1 Answer

Answer :

a) Setting the prismatic compass over prefixed survey station

b) Centering the compass over nail point of station using plumb bob

c) Leveling of compass in horizontal plane using level tube

d) Focusing of prism by raising and lowering the focussing stud
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Related questions

Explain the temporary adjustments of prismatic compass.

Description : Explain the temporary adjustments of prismatic compass.

Last Answer : Temporary Adjustments of Prismatic Compass 1. Fixing the compass to the tripod The compass is fixed on a tripod by rotating screw head of tripod stand. 2. Centering the compass The prismatic compass ... prism is moved using focusing stud so that readings on graduated ring will be seen clearly. 

State any eight component parts with its functions of prismatic compass.

Description : State any eight component parts with its functions of prismatic compass. 

Last Answer : Component parts of prismatic compass are as follows. 1. Break pin - It is used to stop the oscillations of aluminum ring. 2. Lifting pin - It lifts the magnetic needle when sight vane is folded. ... and sighting vane when the compass is not in use to protect the compass from dirt, dust etc.

State the meaning of local attraction and state its effect on prismatic compass and how it taken care of.

Description : State the meaning of local attraction and state its effect on prismatic compass and how it taken care of. 

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.  Effect on prismatic compass: ... compass. 3) If local attraction still persists, it is corrected by mathematical calculation. 

State the function of reflecting mirror in prismatic compass.

Description : State the function of reflecting mirror in prismatic compass. 

Last Answer : Function of reflecting mirror is to get image of an object located above or below the instrument level while bisection.

Why zero is marked at south end on a graduated circle of prismatic compass?

Description : Why zero is marked at south end on a graduated circle of prismatic compass?

Last Answer : As bearing of any line is measured with respective north direction, while observing north direction, reading should be 00 0'. Therefore when object vane is bisecting north direction, at the same ... get bearings with respective north direction always, zero is marked at south end of magnetic needle.

Write the functions of the following components of prismatic compass i) Prism, ii) Lifting pin, iii) Prism cap, iv) Agate cap

Description : Write the functions of the following components of prismatic compass i) Prism, ii) Lifting pin, iii) Prism cap, iv) Agate cap

Last Answer : i) Prism: Reading printed on horizontal face of compass ring can be read from vertical position  ii) Lifting pin: When the instrument not in use the sight vane passes against the lifting pin which lift ... piece of hard glass provided on top of pivoted point, to reduce wear and tear of the point

Draw a neat sketch of prismatic compass and label its component parts

Description : Draw a neat sketch of prismatic compass and label its component parts

Last Answer : Sketch of prismatic compass and label its component parts

Draw labeled sketch of prismatic compass.

Description : Draw labeled sketch of prismatic compass.

Last Answer : Sketch of prismatic compass :

State and explain temporary adjustments of dumpy level.

Description : State and explain temporary adjustments of dumpy level.

Last Answer : 1. Setting up the level. a. The level fixed on tripod. b. The legs of tripod stand are well spread so that the level will remain stable on tripod. c. Bring all the three foot screws ... screw till the image is distinct and clear. The cross hair on the diaphragm should also be seen clearly. 

State any four sources of errors in compass survey

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. 

State different methods of plotting compass traverse.

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.

State the functions of needle, glass cover, pivot and adjustable mirror of a compass.

Description : State the functions of needle, glass cover, pivot and adjustable mirror of a compass.

Last Answer : Needle: To direct north-south direction or to give magnetic meridian. Glass cover: To prevent entry of dust in box and movement of needle due to air or wind. Pivot: To support and balance the ... it is in use. Adjustable mirror: For sighting object at high or below level of observer's eye.

State the principle of compass survey.

Description : State the principle of compass survey. 

Last Answer : The principle of compass survey is traversing, which involves a series of connected survey lines (may be open or closed) whose lengths and bearing are measured by linear and angular measuring instruments.

Explain Procedure for chain and compass traversing.

Description : Explain Procedure for chain and compass traversing.

Last Answer : Chain and compass traversing : 1) Reconnaissance of the area to be surveyed is done. 2) Traverse stations are fixed. 3) The F.B and B.B of the traverse are measured by prismatic compass and ... occur when the traverse is plotted. 6) This error is adjusted graphically by using Bowditch Rule'. 

Enlist different errors in compass surveying.

Description : Enlist different errors in compass surveying.

Last Answer : Various errors in compass surveying are classified asi) Instrumental errors. ii) Personal errors or observational errors iii) Errors caused due to external errors (natural errors) i) ... magnetic declination. c) Local attraction due to proximity of magnetic substances or magnetic field.

With neat sketch, explain the included angle method of plotting compass traverse.

Description : With neat sketch, explain the included angle method of plotting compass traverse. 

Last Answer : 1. Calculate all included angles of the traverse from observed bearings of the lines. e.g. <A, <B, <C, <D, <E  2. Check sum of included angles as equal to ( ... coincide with starting station (in case of closed traverse). If there is closing error, it needs to be corrected. 

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

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

Describe in brief errors in compass survey.

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.

Explain temporary adjustment.

Description : Explain temporary adjustment.

Last Answer : 1) Place the telescope parallel to foot screw (fig. a) 2) Bring the bubble at Centre by moving foot screw inward or outward simultaneously. 3) Then turn the telescope through 900 so that it ... 6) Once both positions give centered bubble, leveling of instrument is said to be completed.

Explain temporary adjustment of plane table survey.

Description : Explain temporary adjustment of plane table survey.

Last Answer : 1. Setting over the station: The plane table is fixed on tripod and adjust the table in such a way that table is approximately level. 2. Leveling the table: The tubular or spirit level is placed in two ... . The table can be oriented in two ways. i. Using trough compass. ii. By back sighting.

The zero of the graduated circle of a prismatic compass is located at (A) North end (B) East end (C) South end (D) West end

Description : The zero of the graduated circle of a prismatic compass is located at  (A) North end  (B) East end  (C) South end  (D) West end 

Last Answer : (C) South end

Prismatic compass is considered more accurate than a surveyor's compass, because (A) It is provided with a better magnetic needle (B) It is provided with a sliding glass in the object vane (C) Its graduations are in whole circle bearings (D) It is provided with a prism to facilitate reading of its graduated circle

Description : Prismatic compass is considered more accurate than a surveyor's compass, because (A) It is provided with a better magnetic needle (B) It is provided with a sliding glass in the object vane ( ... whole circle bearings (D) It is provided with a prism to facilitate reading of its graduated circle

Last Answer : (D) It is provided with a prism to facilitate reading of its graduated circle

In chain surveying, perpendiculars to the chain line are set out by (A) A theodolite (B) A prismatic compass (C) A level (D) An optical square

Description : In chain surveying, perpendiculars to the chain line are set out by (A) A theodolite (B) A prismatic compass (C) A level (D) An optical square

Last Answer : (D) An optical square

In a perfect prismatic compass (A) Magnetic axis and geometric axis of the needle coincide (B) Ends of the needle and pivot are in same vertical and horizontal planes (C) Pivot is vertically over the centre of the graduated circle (D) All the above

Description : In a perfect prismatic compass (A) Magnetic axis and geometric axis of the needle coincide (B) Ends of the needle and pivot are in same vertical and horizontal planes (C) Pivot is vertically over the centre of the graduated circle (D) All the above

Last Answer : (D) All the above

Which one of the following statements is not correct ? (a) A surveyor’s compass has two sight vanes (b) A prismatic compass has an object vane and an eye vane (c) A trough compass is an accessory to a plane table (d) In a prismatic compass the graduations on the aluminimum disc rotate and the index remains stationary

Description : Which one of the following statements is not correct ? (a) A surveyor's compass has two sight vanes (b) A prismatic compass has an object vane and an eye vane (c) A trough compass ... table (d) In a prismatic compass the graduations on the aluminimum disc rotate and the index remains stationary

Last Answer : (a) A surveyor’s compass has two sight vanes

The survey instrument used for reconnaissance survey (a) Theodelite & Dumpty level (b) Prismatic compass & Aneriod barometer* (c) All the above (d) None of them

Description : The survey instrument used for reconnaissance survey (a) Theodelite & Dumpty level (b) Prismatic compass & Aneriod barometer* (c) All the above (d) None of them

Last Answer : (b) Prismatic compass & Aneriod barometer*

Which of the instruments is not used in Reconnaissance survey. (a) Prismatic compass (b) Dumpy level * (c) Aneroid Barometer (d) Pedometer

Description : Which of the instruments is not used in Reconnaissance survey. (a) Prismatic compass (b) Dumpy level * (c) Aneroid Barometer (d) Pedometer

Last Answer : (b) Dumpy level *

List any eight component parts of prismatic compass with their function in brief.

Description : List any eight component parts of prismatic compass with their function in brief.

Last Answer : Component parts of compass with their function. Sr.No Component Function 1 Circular metal box  To protect needle and pivot. 2 Steel pivot To carry magnetic ... prism to eye sight of observer 14 Magnetic needle To obtain the north direction. 

Which one of the following statements is not correc t? (a) Parallax error is eliminated when there is no change in the staff reading when eye is moved up and down (b) The objective lens is to be focused towards a white or bright background for clear visibility of cross-hairs (c) Temporary adjustments of the dumpy level are to be performed at every set up (d) The eyepiece need not be adjusted after the first set up when the same surveyor is taking readings

Description : Which one of the following statements is not correc t? (a) Parallax error is eliminated when there is no change in the staff reading when eye is moved up and down (b) The objective lens is ... (d) The eyepiece need not be adjusted after the first set up when the same surveyor is taking readings

Last Answer : (b) The objective lens is to be focused towards a white or bright background for clear visibility of cross-hairs

State the fundamental axes and mention their relationship for a dumpy level.

Description : State the fundamental axes and mention their relationship for a dumpy level.

Last Answer : Fundamental axis of dumpy level are as follows; i) The vertical axis ii) The axis of bubble tube iii) The line of collimation iv) The axis of the telescope Relationship between ... iii) Axis of telescope and line of collimation should coincide when dumpy level is correctly leveled.

State the situation where plane table is suitable.

Description : State the situation where plane table is suitable. 

Last Answer : 1) It is most suitable for preparing small scale maps 2) It is suitable in magnetic are where compass survey is not reliable 3) It is most suitable for filling in details between stations fixed by triangulation 4) It is suitable where accuracy is not required.

State the two uses of survey based on geodetic surveying

Description : State the two uses of survey based on geodetic surveying

Last Answer : Two uses of survey based on geodetic surveying:- i) To determine the precise position s on the surface of the earth. ii) Preparation of maps of large area like map of a country, state ... ) Establishment of GTS bench Marks across the country. iv) Preparation of military maps for defense purposes.

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 the purposes of following methods of leveling. i)Profile leveling, ii)Fly leveling, iii)Check leveling iv)Reciprocal leveling

Description : State the purposes of following methods of leveling. i)Profile leveling, ii)Fly leveling, iii)Check leveling iv)Reciprocal leveling

Last Answer : 1. Profile leveling- To determine the undulation of ground surface along given line for alignment of road, canal or pipe, railway line 2. Fly leveling-It is used to for connecting B.M. to ... is used to find the difference in leveling between two points two point obstructed due to river or pond.

State fundamental lines and their relationships with each other of dumpy level.

Description : State fundamental lines and their relationships with each other of dumpy level.

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 ... to the axis of the bubble tube. iii) Axis of telescope and line of collimation should coincide.

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

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

Last Answer : Booking of observations: i) Field work and plotting work done simultaneously ii) ) Notes of measurement are seldom required and possibility of mistakes in booking is eliminated. Suitability of PT ... and work where great accuracy is not required. ii) Mostly suitable for survey in plain terrain

State two advantages of telescopic alidade over simple alidade.

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

Last Answer : Advantages of telescopic alidade : i) Telescopic alidade is more accurate in bisection than simple alidade ii) Telescopic alidade is useful in comparatively longer range objects. iii) It can be easily ... is not possible by simple alidade. iv) It gives quicker bisection which saves time ultimately.

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.

State four instruments used for setting offsets.

Description : State four instruments used for setting offsets.

Last Answer : i) Instruments used for setting offsets: 1)Chain 2)Tape 3) Open & French Cross Staff 4) Circular & Indian Optical Square  ii) Principle of optical square: The angle between the first incident ray and the last reflected ray is twice to that of angle between two mirrors in optical square.

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 

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

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

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

Last 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. ... lines in a closed traverse. 2. It is used to calculate back bearing for respective quadrants.

State and describe the types of offsets.

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.

State any two uses of survey.

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.

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

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

State fundamental axis of dumpy level and give their relationship

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. 

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

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

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.

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

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. 

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

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.