1. What is Surveying?
Surveying is a scientific method of measuring distances, directions, angles, and elevations between different points on the earth’s surface to obtain accurate data for construction works, mapping, and land development.
2. What are the objectives of Surveying?
The main objective of surveying is to determine the shape, area, boundaries, levels, slopes, and position of land so that the design of roads, buildings, canals, bridges, or any engineering project can be set with accuracy.
3. Define Plane Surveying.
Plane surveying refers to the technique where the earth is assumed to be a flat surface. It is suitable for small areas where the effect of curvature is negligible and ordinary construction work is carried out.
4. Define Geodetic Surveying.
Geodetic surveying is performed over large areas with high precision while considering the curvature of the earth. It is used for national boundaries, major engineering projects, and scientific measurements.
5. What is Reconnaissance?
Reconnaissance is the preliminary inspection of the site where the surveyor examines obstacles, slopes, water sources, access routes, and possible survey lines to plan the detailed survey effectively.
6. Explain “Working from Whole to Part.”
This principle states that a large, strong, and accurate control framework must be established first, and the detailed survey should proceed into smaller parts to minimize error propagation.
7. What is a Benchmark?
A benchmark is a fixed reference point whose elevation (RL) is accurately known. GTS benchmarks or permanent marks are used to determine the elevations of other points.
8. What is Datum?
Datum is a reference surface, such as the Mean Sea Level (MSL), from which all heights and depths are measured. It serves as the base for leveling and contour mapping.
9. Difference between Accuracy and Precision.
Accuracy refers to how close a measured value is to the actual value, whereas precision refers to how consistently repeated measurements produce similar results. Both are essential in surveying.
10. What is a Map?
A map is a scaled representation of the earth’s surface that includes significant natural and man-made features. It helps in planning, navigation, and analysis of an area.
11. What is a Plan?
A plan is a detailed drawing of a small area such as a plot or building, showing only horizontal details. It is drawn to a larger scale compared to maps.
12. Write types of errors in surveying.
There are three types of errors in surveying: Gross errors, Systematic errors, and Random errors. These are minimized through repetition, calibration, and correction techniques.
13. What is a True Meridian?
The true meridian is the direction that passes through the true north, based on earth’s rotational axis. It is used as a reference for correcting compass bearings.
14. What is a Magnetic Meridian?
Magnetic meridian is the direction in which a magnetic compass needle aligns. Since magnetic north varies with time and location, declination correction is required.
15. What is Magnetic Declination?
Magnetic declination is the angle between magnetic north and true north. It changes due to variations in the earth’s magnetic field and must be corrected in compass surveys.
16. What is Local Attraction?
Local attraction occurs when nearby metallic objects or magnetic materials disturb the compass needle, causing incorrect bearings. It is corrected by comparing FB and BB readings.
17. What is GIS?
A Geographic Information System (GIS) is a computer-based tool for collecting, managing, analyzing, and displaying geographical data. It is widely used in urban planning and resource management.
18. What is GPS?
The Global Positioning System (GPS) uses satellites to determine precise position, elevation, and time of any point on earth. It is highly useful in surveying and mapping.
19. Define Scale.
Scale is a ratio representing the relationship between a distance on a map and the corresponding distance on the ground. Large scales show more details than small scales.
20. Explain the need of Surveying.
Surveying is essential to determine correct position, level, direction, and dimensions for construction works such as roads, bridges, buildings, and canals. Without it, no project can be safely designed.
Unit–2: Linear Measurement (20 Questions)
21. What is Chain Surveying?
Chain surveying uses only linear measurements and is best suited for small, clear, and level areas. It is mainly used for determining boundaries and simple site mapping.
22. Instruments used in Chain Surveying.
Chain, tape, ranging rods, arrows, cross-staff, pegs, and plumb bob are commonly used. Each instrument helps in alignment and accurate measurement of survey lines.
23. What is Ranging?
Ranging is the process of establishing a straight line between two survey points to ensure accurate tape or chain measurement. Proper ranging reduces measurement errors.
24. Types of Ranging.
Ranging is of two types: Direct ranging, used in open straight lines, and Indirect ranging, used in obstructed areas using intermediate signals.
25. What is an Offset?
An offset is the perpendicular or oblique distance taken from a survey line to locate details such as trees, walls, or roads for accurate plotting.
26. Types of Offsets.
Offsets are of two types: Perpendicular offsets taken at 90°, and Oblique offsets taken at any angle. Both are useful for detailed mapping.
27. What is a Baseline?
A baseline is the main survey line that controls the overall survey. All tie lines and offsets originate from it, forming the basis for plotting.
28. What is a Check Line?
A check line is used to verify the accuracy of the survey. If the measured and calculated lengths closely match, the survey is considered reliable.
29. What is a Tie Line?
A tie line connects two main survey lines and helps improve the detailing of the plot. It increases the accuracy of closed traverses.
30. What is a Well-Conditioned Triangle?
A well-conditioned triangle has angles between 30° and 120°. Such triangles reduce error propagation and improve plotting accuracy.
31. Errors in Chain Survey.
Errors in chain surveying occur due to temperature, tension, sagging, personal mistakes, and incorrect ranging. Corrections and careful handling minimize these errors.
32. What is Sag Error?
Sag error occurs when the chain sags due to its weight instead of remaining straight. It always gives a negative error and must be corrected.
33. What is Tape Correction?
Tape correction is applied when the actual length of a tape differs from its standard length. Temperature, pull, and sag corrections are added for true length.
34. Difference between Tape and Chain.
A tape is lighter, more accurate, and made of steel or fiber, while a chain is heavier, stronger, and less accurate, making it suitable for rough areas.
35. What is Direct Measurement?
Direct measurement means measuring distance directly using a tape or chain. It is simple, quick, and suitable for small areas.
36. What is Indirect Measurement?
Indirect measurement uses trigonometric formulas, angles, and leveling when direct measurement is not possible, such as across rivers or valleys.
37. What is Personal Error?
Personal error occurs due to mistakes by the surveyor, such as incorrect readings, improper alignment, or wrong arrow counting. Training helps reduce it.
38. What is Systematic Error?
Systematic errors occur consistently in one direction, such as due to incorrect tape length, temperature effects, or constant sag. These can be corrected mathematically.
39. What is Random Error?
Random errors occur due to unpredictable causes like wind, vibration, or poor visibility. Statistical averaging is used to reduce them.
40. What is Chaining on Slope?
Chaining on a slope requires stepping or applying slope correction to obtain true horizontal distance. It ensures accuracy on uneven ground.
Unit–3: Compass Surveying (15 Questions)
41. What is Compass Surveying?
Compass surveying involves measuring directions using a compass and distances using a tape. It is useful for large, irregular, and forested areas.
42. Types of Compass.
Two main types are: Prismatic Compass, where readings are taken directly, and Surveyor’s Compass, which uses quadrant bearings. Both differ in least count.
43. What is Bearing?
Bearing is the direction of a survey line measured as a clockwise angle from north or south. It helps plot and analyze traverse lines.
44. Types of Bearings.
There are two types: Whole Circle Bearing (0–360°) and Quadrantal Bearing (N/S to E/W). Conversion between them is often required.
45. What is Fore Bearing (FB)?
Fore bearing is the direction of the line measured from the starting point to the ending point. It is important for plotting and correction.
46. What is Back Bearing (BB)?
Back bearing is taken in the reverse direction of the line and usually equals FB ± 180°. It is used to check local attraction.
47. What is Dip?
Dip is the angle at which the magnetic needle is inclined downward due to the earth’s magnetic field. In the northern hemisphere, the needle dips downward.
48. Explain Local Attraction Correction.
Local attraction correction is done by selecting lines where FB and BB differ by exactly 180°. Deviations in other lines are corrected accordingly.
49. What is a Traverse?
A traverse is a series of connected survey lines whose bearings and distances are measured to prepare a plot. It can be open or closed.
50. What is a Closed Traverse?
A closed traverse forms a closed polygon where the start and end points meet. It is best for area calculation and mapping.
51. What is an Open Traverse?
An open traverse does not return to the starting point and is used for roads, canals, and pipelines where only direction matters.
52. Errors in Compass Survey.
Instrumental errors (needle, pivot), personal errors (wrong readings), and natural errors (declination, magnetic attraction) commonly occur and must be corrected.
53. What is a Magnetic Needle?
A magnetic needle is a slender steel strip that aligns itself with magnetic north. Bearings are based on its alignment inside the compass.
54. What is a Prismatic Compass?
A prismatic compass allows readings to be viewed and taken simultaneously through a prism. Its least count is 30 minutes, making it ideal for field work.
55. What is Surveyor’s Compass?
Surveyor’s compass uses the quadrantal bearing system and has reduced needle oscillations. It is mainly used for small surveys and rough work.
Unit–4: Levelling (20 Questions)
56. What is Levelling?
Levelling is the process of determining the elevation of various points. It is essential for roads, canals, drainage, dams, and foundation levels.
57. What is Level Surface?
A level surface is equidistant from the earth’s center and is therefore curved. Its tangent is known as the horizontal line.
58. What is a Horizontal Line?
A horizontal line is a straight line tangential to the level surface. All elevation measurements are taken using this line as reference.
59. What is Vertical Line?
A vertical line follows the direction of gravity. It is indicated by a plumb bob and is perpendicular to the horizontal line in leveling.
60. What is Back Sight (B.S.)?
Back sight is the first reading taken on a known RL point after setting up the instrument. It helps determine the height of instrument (HI).
61. What is Fore Sight (F.S.)?
Fore sight is the last reading taken before shifting the instrument. It is taken on an unknown point to determine its RL.
62. What is Intermediate Sight (I.S.)?
Intermediate sights are readings taken between BS and FS to determine elevations of multiple intermediate ground points.
63. What is a Change Point?
A change point is the point where an FS is taken and then becomes the next BS after repositioning the instrument. It helps transfer HI.
64. What is Height of Instrument (HI)?
The height of instrument is obtained by adding BS to the benchmark RL. It is used to calculate RLs of all other points.
65. Define Reduced Level (RL).
Reduced level is the height of any point measured from a datum such as MSL. It is essential for comparing elevations.
66. What is a Contour?
A contour is a curve connecting points of equal elevation. It shows the shape of land, such as hills, slopes, and valleys.
67. Characteristics of Contours.
Contours never intersect, are closely spaced in steep slopes, widely spaced in gentle slopes, and closed loops represent hills or depressions.
68. What is Contour Interval?
Contour interval is the vertical distance between consecutive contour lines. It depends on terrain nature and map scale.
69. What is Temporary Adjustment?
Temporary adjustment includes centering, leveling, and focusing the instrument at every setup to ensure accurate readings.
70. What is Permanent Adjustment?
Permanent adjustment aligns internal parts of the instrument, ensuring proper collimation and bubble alignment through calibration.
71. What is a Staff?
A leveling staff is a graduated rod used to take readings through the telescope. It usually ranges from 3 to 5 meters.
72. Types of Staff.
The main types are self-reading staff, target staff, and invar staff. Each offers different accuracy and visibility advantages.
73. What is Differential Levelling?
It is used to determine the elevation difference between two points using successive BS and FS readings, suitable for long distances.
74. What is Fly Levelling?
Fly leveling is used to quickly transfer a benchmark to another location using only BS and FS readings for accuracy.
75. Errors in Levelling.
Errors may arise due to instrument defects, personal mistakes, natural effects, and collimation errors. Proper adjustment minimizes them.
76. What is Curvature Correction?
Curvature correction is applied because the earth is curved. Over long distances, the line of sight appears higher, requiring correction.
77. What is Refraction Correction?
Refraction bends light rays, making objects appear higher. Refraction correction is opposite to curvature correction and both together give true reading.
78. What is Collimation Error?
Collimation error arises when the line of sight is not truly horizontal due to instrument misalignment. Permanent adjustments remove it.
79. What is Reciprocal Levelling?
Reciprocal leveling is used when equal visibility from both ends is not possible. Taking BS and FS from both ends removes errors.
80. What is Profile Levelling?
Profile leveling involves taking ground levels along the alignment of a road, canal, or pipeline for preparing a longitudinal section.
Unit–5: Theodolite Surveying (15 Questions)
81. What is a Theodolite?
A theodolite is a precision instrument used to measure horizontal and vertical angles with high accuracy. It is used in triangulation and alignment.
82. Types of Theodolite.
Two main types are Transit theodolite, whose telescope can rotate 180°, and Non-transit theodolite with limited telescope movement.
83. What is Transiting?
Transiting is rotating the telescope vertically by 180°, resulting in face left and face right positions for error elimination.
84. What is Swinging?
Swinging is rotating the telescope in the horizontal plane to measure angles at different stations using the horizontal circle.
85. What is Face Left Observation?
When the vertical circle is on the left side of the observer, the position is called face left. Both faces are used for accuracy.
86. What is Face Right Observation?
When the vertical circle lies on the right side of the observer, it is face right. Averaging both faces reduces errors.
87. What is Reiteration Method?
Reiteration involves measuring several angles repeatedly and averaging them. It is suitable for polygonal surveys and closed traverses.
88. What is Repetition Method?
Repetition method measures the same angle multiple times and divides the accumulated reading to eliminate minor errors.
89. What is Vertical Angle?
A vertical angle is formed between the line of sight and horizontal plane. It indicates elevation or depression of objects.
90. What is a Line of Sight?
Line of sight is an imaginary straight line from the telescope’s optical center to the crosshair. Its correct adjustment ensures accuracy.
Unit–6: Area & Volume (10 Questions)
91. What is Trapezoidal Rule?
Trapezoidal rule calculates area by taking the average of adjacent ordinates multiplied by the base length. It is suitable for uneven surfaces.
92. Explain Simpson’s Rule.
Simpson’s rule is applied when the number of ordinates is odd. The area is calculated using the formula involving 1st, last, 4×odd, and 2×even ordinates.
93. What is a Prismoid?
A prismoid is a solid whose top and bottom surfaces are parallel. Its volume is computed using the prismoidal formula in earthwork.
94. What is Earthwork?
Earthwork includes calculating cutting and filling quantities required for roads, canals, embankments, and foundations, ensuring proper soil management.
95. What is Cross-Sectioning?
Cross-sectioning involves taking perpendicular sections along an alignment to determine cutting and filling quantities for roadway construction.
96. What is Longitudinal Section?
A longitudinal section is a profile taken along the centerline of a road, railway, or canal showing slopes, depressions, and gradients.
97. What is a Spot Level?
A spot level is the elevation of any specific ground point. It is essential in grid leveling and contouring to understand terrain height.
98. What is Grid Levelling?
Grid leveling divides the ground into square grids and records levels at each grid corner. It helps create contour maps easily.
99. What is Mass Haul Diagram?
A mass haul diagram shows the balance between cutting and filling in earthwork. It indicates where soil is available and where it needs to be transported.
100. What is Interpolation of Contours?
Interpolation is the process of determining unknown contour points between known elevations using equal spacing and proportional division.
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