Introduction
Welcome to the ultimate guide on chain surveying interview questions, your passport to conquering the challenging terrain of surveyor job interviews. In this article, we’ll explore the top 100 questions, providing in-depth answers and valuable tips to ensure you’re well-prepared for success.
1. What is Chain Surveying?
- Answer: Chain surveying is a method of surveying in which a chain or tape is used for measuring distances on the field.
2. Why is Chain Surveying called so?
- Answer: It is called chain surveying because a chain or tape is used to measure distances during the survey.
3. What are the basic instruments used in chain surveying?
- Answer: The basic instruments used in chain surveying are a chain or tape, ranging rods, arrows, and pegs.
4. What is the purpose of a ranging rod in chain surveying?
- Answer: A ranging rod is used to mark the end points of the survey line and to ensure straight alignment during measurement.
5. Explain the term “chaining.”
- Answer: Chaining is the process of measuring distances using a chain or tape in chain surveying.
6. What are the different types of chains used in surveying?
- Answer: Common types of chains used are Metric chains, Engineer’s chains, and Revenue chains.
7. Explain the concept of a baseline in chain surveying.
- Answer: A baseline is a measured line in the survey area from which other survey lines are referenced and measured.
8. What is the purpose of a survey station in chain surveying?
- Answer: A survey station is a point where the survey line changes direction, and measurements are taken from this point.
9. How do you deal with obstacles like buildings or rivers in chain surveying?
- Answer: Obstacles are bypassed using offsets, and measurements are taken from a convenient point to the obstacle.
10. Define the term “offset.”
- Answer: An offset is a perpendicular line from a survey line to the location of an obstacle, such as a building or a river.
11. What is the purpose of arrows in chain surveying?
- Answer: Arrows are used to mark the points on the ground where measurements are to be taken.
12. Explain the term “booking” in chain surveying.
- Answer: Booking is the process of recording measurements and other relevant data during the survey.
13. What is the importance of a check line in chain surveying?
- Answer: A check line is used to verify the accuracy of the survey by comparing the measured lengths with calculated lengths.
14. Differentiate between a tie line and a tie line offset.
- Answer: A tie line is a line connecting two survey stations, while a tie line offset is a perpendicular measurement from a tie line to a particular point.
15. How is a chain taped measured and recorded?
- Answer: The chain or tape is stretched, aligned properly, and measurements are taken from the end of the chain. The readings are recorded in the booking.
16. What are the limitations of chain surveying?
- Answer: Limitations include errors due to sagging of the chain, temperature variations, and limitations in measuring irregular ground.
17. Explain the term “conventional signs” in chain surveying.
- Answer: Conventional signs are symbols used on a survey map to represent features like trees, buildings, and roads.
18. How do you calculate the area in chain surveying?
- Answer: The area is calculated using the principle of triangulation or by dividing the survey area into triangles and calculating their areas.
19. What is a survey traverse?
- Answer: A survey traverse is a series of connected survey lines forming a closed figure, commonly used for small surveys.
20. How do you deal with sloping ground in chain surveying?
- Answer: The slope is accounted for by taking slope corrections or inclined measurements.
21. Explain the concept of “cross staff” in chain surveying.
- Answer: A cross staff is an instrument used to set right angles in chain surveying.
22. What is the purpose of a surveyor’s compass in chain surveying?
- Answer: A surveyor’s compass is used to determine magnetic bearings and angles during the survey.
23. How do you deal with errors in chain surveying?
- Answer: Errors are minimized by careful measurement, proper equipment use, and systematic checks during the survey.
24. Explain the term “reduction factor” in chain surveying.
- Answer: The reduction factor is a correction factor applied to measured distances to account for temperature and tension variations in the chain.
25. What is the purpose of a prismatic compass in chain surveying?
- Answer: A prismatic compass is used to measure angles and bearings during the survey.
26. How do you measure a horizontal angle in chain surveying?
- Answer: Horizontal angles are measured using a theodolite or a prismatic compass.
27. Define the term “meridian” in chain surveying.
- Answer: The meridian is a north-south reference line used for measuring angles and bearings in surveying.
28. Explain the purpose of a traverse table in chain surveying.
- Answer: A traverse table is used to calculate the interior angles of a traverse.
29. How do you handle the chaining on steep slopes?
- Answer: Steep slopes are tackled by measuring the horizontal distances and then applying a slope correction.
30. Define the term “linear measurement” in chain surveying.
- Answer: Linear measurement refers to the measurement of distances along a straight line in surveying.
31. What are the advantages of chain surveying over other surveying methods?
- Answer: Chain surveying is simple, cost-effective, and suitable for small-scale surveys.
32. How do you establish a temporary benchmark in chain surveying?
- Answer: A temporary benchmark is established using a leveling instrument to determine a known elevation.
33. Explain the term “bearing” in chain surveying.
- Answer: Bearing is the direction of a line with respect to the meridian, usually expressed in degrees.
34. What is a subsidiary angle in chain surveying?
- Answer: A subsidiary angle is an angle measured in addition to the main angles in a traverse.
35. How do you measure the true bearing of a line?
- Answer: True bearing is obtained by combining the magnetic bearing with the magnetic declination.
36. Define the term “reciprocal bearing” in chain surveying.
- Answer: Reciprocal bearing is the bearing of a line measured in the opposite direction.
37. How is a chain or tape tested for accuracy?
- Answer: A chain or tape is tested by comparing its length with a standard, and corrections are applied if necessary.
38. What is the purpose of a surveyor’s level in chain surveying?
- Answer: A surveyor’s level is used to determine the difference in elevation between two points.
39. Explain the term “triangulation” in chain surveying.
- Answer: Triangulation is the method of surveying where the survey area is divided into a series of triangles for measurement.
40. How is a chain adjusted for temperature variations?
- Answer: A chain is adjusted by applying a correction factor based on the temperature at the time of measurement.
41. Define the term “back bearing” in chain surveying.
- Answer: Back bearing is the bearing of a line measured in the opposite direction to its original measurement.
42. What is the role of a compass in chain surveying?
- Answer: A compass is used to determine the magnetic bearing of a line.
43. Explain the term “transit theodolite” in chain surveying.
- Answer: A transit theodolite is an instrument used for measuring horizontal and vertical angles in surveying.
44. How do you deal with errors in chaining due to sag?
- Answer: Sag corrections are applied by measuring the horizontal distances at different tensions in the chain.
45. Define the term “contour line” in chain surveying.
- Answer: A contour line is a line connecting points of equal elevation on the ground.
46. What is the purpose of a surveyor’s chain in chain surveying?
- Answer: A surveyor’s chain is used for linear measurements in surveying.
47. How do you measure a slope distance in chain surveying?
- Answer: A slope distance is measured along the slope, and a correction is applied to obtain the horizontal distance.
48. Explain the concept of “subsidiary chain” in chain surveying.
- Answer: A subsidiary chain is a smaller chain used for detailed measurements within a survey.
49. What is the significance of a magnetic meridian in chain surveying?
- Answer: The magnetic meridian is used as a reference line for measuring magnetic bearings and angles in surveying.
50. How do you calculate the area of irregular plots in chain surveying?
- Answer: The area of irregular plots is calculated by dividing the plot into triangles and applying the principle of triangulation. The area of each triangle is then calculated and summed up.
51. What is a check line in a chain survey, and why is it important?
- Answer: A check line is an additional line used to verify the accuracy of the survey. It is important as it helps detect and correct errors in measurements.
52. Explain the term “meridian convergence” in chain surveying.
- Answer: Meridian convergence is the angular difference between the true meridian and the magnetic meridian, which needs to be considered when measuring angles.
53. How is the length of a chain or tape affected by temperature changes, and how is it corrected?
- Answer: Chains and tapes expand or contract with temperature changes. The correction is made using the temperature correction formula.
54. What are the common mistakes to avoid in chain surveying?
- Answer: Common mistakes include inaccurate chaining, misalignment, not compensating for obstacles, and inadequate record-keeping. Diligence and attention to detail can prevent these errors.
55. Explain the concept of “slope correction” in chain surveying.
- Answer: Slope correction is the adjustment made to the measured slope distance to obtain the horizontal distance. It accounts for the incline of the terrain.
56. How do you choose the type of chain for a specific surveying task?
- Answer: The choice depends on the accuracy required, the nature of the terrain, and the working conditions. Engineer’s chains are suitable for rough terrains, while metric chains provide greater precision.
57. What precautions should be taken during chain surveying in adverse weather conditions?
- Answer: In adverse weather, protect equipment from rain and wind. Avoid measurements during extreme temperatures, as these can affect the accuracy of the chain or tape.
58. Explain the purpose of a stadia rod in chain surveying.
- Answer: A stadia rod is used with a stadia diaphragm on a telescope to measure horizontal distances and elevations in chain surveying.
59. How do you establish a chain line on a ground with irregularities?
- Answer: In the presence of irregularities, the chain line is established by taking offsets or by using tie lines. The aim is to maintain accuracy despite the irregular terrain.
60. What is a magnetic declination, and how is it used in chain surveying?
- Answer: Magnetic declination is the angle between the magnetic meridian and the true meridian. It is considered when determining true bearings from magnetic bearings.
61. Explain the purpose of a hand level in chain surveying.
- Answer: A hand level is a simple instrument used to estimate the difference in elevation between two points. It aids in rough leveling during a survey.
62. How do you ensure the straightness of a chain or tape during measurement?
- Answer: Straightness is ensured by stretching the chain or tape properly and avoiding kinks or bends. Ranging rods are used at each end to maintain alignment.
63. What are the steps involved in setting up a survey station?
- Answer: Setting up a survey station involves selecting a stable point, leveling the instrument, and marking the station clearly. The point should offer good visibility to surrounding stations.
64. Explain the term “tangential angles” in chain surveying.
- Answer: Tangential angles are angles measured at a station between the lines to the next and the preceding stations. They help in closing a traverse.
65. How is the arithmetic mean of the latitudes and departures used in chain surveying?
- Answer: The arithmetic mean of latitudes and departures is used to check the closure error in a traverse. If the sums are equal, the traverse is closed.
66. What is the purpose of a surveyor’s chain tape in chain surveying?
- Answer: A surveyor’s chain tape is a flexible measuring tape used for irregular or curved measurements. It provides flexibility compared to a rigid chain.
67. Explain the term “field book” in chain surveying.
- Answer: A field book is a notebook used by surveyors to record measurements, sketches, and other relevant data during the survey.
68. How do you calculate the area of a field when only the lengths of sides are known?
- Answer: The area is calculated using the formula for the area of a polygon: Area = 0.5 * n * Perimeter * Apothem, where n is the number of sides.
69. What is the purpose of a prismatic compass in chain surveying?
- Answer: A prismatic compass is used to measure angles and bearings in chain surveying. It is particularly useful in rough terrains.
70. Explain the term “offset survey” in chain surveying.
- Answer: An offset survey involves measuring perpendicular distances from a survey line to specific points of interest, such as buildings or trees.
71. How do you handle chaining over a water body or river?
- Answer: Chaining over water bodies is done using offsets or by measuring along the banks. The measured distance is then corrected for slope if necessary.
72. What are the advantages and disadvantages of chain surveying compared to modern surveying methods?
- Answer: Advantages include simplicity and cost-effectiveness, while disadvantages include limitations in accuracy and efficiency for large-scale surveys.
73. Explain the term “interior angle” in chain surveying.
- Answer: An interior angle is the angle formed between two consecutive survey lines at a survey station.
74. How does a chain or tape correction affect the accuracy of the survey?
- Answer: Chain or tape corrections, such as temperature corrections, are crucial for maintaining accuracy in measurements and ensuring reliable survey results.
75. Define the term “subsidiary survey” in chain surveying.
- Answer: A subsidiary survey is a supplementary survey conducted to gather detailed information within a specific area covered by the main survey.
76. What is a compass survey in chain surveying, and when is it used?
- Answer: A compass survey involves measuring angles using a compass. It is used when accurate angular measurements are required, especially in areas with magnetic variations.
77. Explain the term “closed traverse” in chain surveying.
- Answer: A closed traverse is a series of connected survey lines forming a closed figure. The last point is connected to the first, and the traverse ends where it started.
78. How do you calculate the departure of a line in chain surveying?
- Answer: Departure is calculated by multiplying the length of the line by the sine of the included angle.
79. What is the purpose of a surveyor’s cross-staff in chain surveying?
- Answer: A surveyor’s cross-staff is used to set right angles and measure offsets in chain surveying.
80. Explain the concept of “alignment” in chain surveying.
- Answer: Alignment refers to the proper positioning and straightness of the chain or tape during measurements to ensure accurate results.
81. How do you calculate the area of a plot using the graphical method in chain surveying?
- Answer: The graphical method involves drawing the plot on graph paper and counting the number of squares. Each square represents a known area, and the total area is calculated accordingly.
82. Define the term “bearing of a line” in chain surveying.
- Answer: The bearing of a line is the direction of the line with respect to the meridian, usually expressed in degrees.
83. What is the purpose of a leveling instrument in chain surveying?
- Answer: A leveling instrument is used to determine the difference in elevation between two points. It is crucial for creating level profiles of the surveyed area.
84. How do you establish a temporary benchmark in the absence of known benchmarks?
- Answer: A temporary benchmark can be established by leveling from a known point or using a GPS device to determine the elevation.
85. Explain the term “compass traverse” in chain surveying.
- Answer: A compass traverse involves measuring angles with a compass and chaining distances. It is useful when magnetic bearings are more accurate than horizontal angles.
86. What precautions should be taken during night surveys in chain surveying?
- Answer: Adequate lighting should be used to ensure accurate measurements. Reflectors or markers may be employed for visibility, and instruments with illumination can be helpful.
87. Define the term “triangulation station” in chain surveying.
- Answer: A triangulation station is a point with known coordinates used as a reference for measuring angles and distances in triangulation surveys.
88. How is the curvature of the Earth considered in chain surveying?
- Answer: For long survey lines, the curvature of the Earth is considered by applying a correction factor to the measured distances.
89. Explain the term “distribution of errors” in chain surveying.
- Answer: Distribution of errors involves spreading errors equally throughout a traverse to minimize their impact on the final results.
90. What is the purpose of a chaining pin in chain surveying?
- Answer: A chaining pin is used to anchor the chain at the starting point of a measurement, ensuring accurate and consistent measurements.
91. How do you calculate the latitude and departure of a line in chain surveying?
- Answer: Latitude is calculated by multiplying the length of the line by the cosine of the included angle, and departure is calculated by multiplying the length by the sine of the included angle.
92. Explain the term “principle of chaining” in chain surveying.
- Answer: The principle of chaining involves measuring distances between points using a chain or tape, maintaining accuracy and precision in the process.
93. What is a check line offset, and how is it measured in chain surveying?
- Answer: A check line offset is a perpendicular measurement from a check line to a station point. It is measured using a chain or tape along the line.
94. How do you choose the appropriate type of chain for different terrains?
- Answer: For rough terrains, Engineer’s chains with rings are preferred for durability. Metric chains are suitable for precise measurements in flat or gentle terrains.
95. Explain the term “tacheometry” in chain surveying.
- Answer: Tacheometry is a method of surveying where horizontal and vertical distances are determined by measuring angles with a tacheometer.
96. What is the purpose of a plumb bob in chain surveying?
- Answer: A plumb bob is used to ensure that the surveying instrument is positioned vertically over a point, aiding in accurate measurements.
97. How do you handle chaining across a busy road or highway in chain surveying?
- Answer: Chaining across busy roads involves coordinating with traffic authorities, ensuring safety, and using signals or signs to manage traffic during measurements.
98. Define the term “gyrotheodolite” in chain surveying.
- Answer: A gyrotheodolite is a surveying instrument that uses a gyroscope to maintain a reference direction, providing accurate measurements even in motion.
99. What is the significance of a control point in chain surveying?
- Answer: A control point is a precisely measured and marked point used as a reference for the survey. It ensures consistency and accuracy in subsequent surveys.
100. How is chaining affected by the presence of magnetic objects in the survey area?
- Answer: Magnetic objects can interfere with compass measurements. It is crucial to avoid such objects or take magnetic corrections into account when measuring angles.