Surveying MCQ Quiz - Objective Question with Answer for Surveying - Download Free PDF

Concept:

Combined correction for curvature and refraction is given by:

C = C_c + C_R

C = - 0.0785 d² + 0.01122 d²

C = - 0.06735 d²

Calculation:

d = 100 m = 0.1 km

C = -0.06735 d²

where d is in km, C is in m

C = - 0.06735 x 0.1² = - 0.000673 m

Explanation:

Given:

• Three consecutive readings:

  • 1.325 m (Backsight, BS)

  • 0.985 m (Foresight, FS — before instrument shifting)

  • 2.546 m (Foresight after shifting — becomes a new BS for next setup)

• The instrument is shifted after the first reading (1.325 m), so:

Classification of Readings:

1. 1st Reading (1.325 m) → BS1

2. 2nd Reading (0.985 m) → FS1

3. 3rd Reading (2.546 m) → BS2

Now, to determine rise or fall, we compare the FS1 and BS2 (as they are from two different instrument stations).

Calculation:

Rise or Fall = BS2 − FS1 = 2.546 − 0.985 = 1.561m rise​

Explanation:

Levelling – First

• The plane table must first be levelled using a spirit level so that all angles and directions can be plotted correctly.

• Levelling ensures the drawing sheet lies in a horizontal plane, which is essential for accurate measurement.

• It is the first and foundational step before proceeding with any plotting.

Centering – Second

• After levelling, the table is centered over the station point using a plumb bob or plumbing fork.

• This ensures that the plotted station point on the drawing sheet lies exactly over the corresponding ground station.

• Proper centering avoids positional errors in the fieldwork and plotting.

Orientation – Third

• Once levelled and centered, the table is oriented using a backsight or compass, aligning it with the previous station or magnetic north.

• Orientation ensures that the direction of the lines drawn corresponds correctly to ground directions.

• Without correct orientation, angular measurements will be inconsistent.

Additional Information

• Plane table survey is a graphical method of surveying where field observations and plotting are done simultaneously on a drawing sheet.

• It operates on the principle of intersection and radiation, allowing direct plotting of angles and distances from a fixed station.

• It eliminates the need for field notes and is ideal for small-scale, moderately accurate surveys.

• The main instruments include a plane table, alidade, spirit level, plumb bob, tripod, and drawing accessories.

• The alidade is used for sighting and drawing rays, while the plumb bob helps in centering the table.

• A spirit level ensures proper levelling, and the tripod provides stability during observations.

Explanation:

Topographical Survey

• This survey aims to represent the natural and man-made features of a region, such as rivers, hills, roads, lakes, and bridges.

• It records elevations and contours, allowing creation of maps that reflect the terrain accurately.

• Used in mapping, land development, route planning, and environmental studies.

• Tools include total stations, theodolites, GPS, and drones for aerial photogrammetry.

Geodetic Survey

• Conducted over large areas, this survey accounts for the earth’s curvature and is used for establishing global and national control points.

• It helps in determining the precise shape and size of the Earth, using triangulation and satellite data.

• Utilized in creating reference frameworks for all other types of surveys.

• Instruments include GNSS receivers, satellite imagery, and high-precision theodolites.

 Additional InformationEngineering Survey

• Performed to collect data necessary for planning, designing, and executing engineering projects like highways, railways, dams, and canals.

• It involves reconnaissance, preliminary, and detailed surveys depending on project stage.

• Provides information on horizontal and vertical alignment, ground profiles, and structures.

• Key tools: levels, total stations, GPS, and surveying software like AutoCAD Civil 3D.

Cadastral Survey

• This survey deals with property boundaries, land ownership, and legal documentation for land registration and taxation.

• Produces maps showing individual plots, field boundaries, buildings, and other fixed features.

• Essential for resolving property disputes, creating land records, and issuing land titles.

• Techniques involve chain surveying, plane table, and now digital cadastral mapping using GIS.

Explanation:

• The principle of "working from whole to part" is followed in surveying to ensure that errors do not accumulate as the survey progresses.
• By first establishing a precise control framework (the "whole"), and then working within that framework for smaller details (the "parts"), the overall accuracy of the survey is maintained and localized errors do not affect the entire survey.

 Additional Information

Principle of "Working from Whole to Part":

• This principle involves first establishing a network of highly accurate control points over the entire survey area. These points serve as a reference framework.

• Once the main framework is established, detailed measurements (such as small features, internal details, and secondary points) are conducted within these control points.

• The method ensures that any small errors in detailed work remain localized and do not affect the entire survey. This prevents the accumulation of errors over large distances or areas.

• It also allows for efficient quality control because the accuracy of local measurements can always be checked against the already established high-precision framework.

The different types of area measuring devices are as follows:

1. Clinometer or Inclinometer: It is used to measure angles of slopes either elevation or depression of an object with respect to gravity direction as reference.

2. Planimeter: It is the mechanical device used to measure area of plane. This measurement consists of dragging along boundary region.

It is semi-circular surveying instrument used to measure angles.

Explanation:

Cadastral survey: Cadastral survey are made incident to the fixing of property lines, the calculation of land area, or the transfer of land property from one owner to another. They are also made to fix the boundaries of municipalities and of state and federal jurisdictions.

Topographical survey: This consist of horizontal and vertical location of certain points by linear and angular measurements and is made to determine the natural features of a country such as rivers, streams, lakes, woods, hills etc and such artificial features like roads, railways etc.

City survey: They are made in connection with the construction of streets, water supply systems, sewers and other works.

Topographical, cadastral and city survey are the parts of Land surveying.

Concept:

The correction due to the wrong alignment of the chain is given by

d - Difference in elevation due to the wrong alignment

L - The sloping length

l - True length

Correction due to the wrong alignment of the chain is always negative

 True length = Measured length - Correction

Calculation:

Given: d = 2 m, L = 50 m

⇒ C = 0.04

True length (l) = 50 - 0.04 = 49.96 m​.

Concept:

The precision of leveling is ascertained according to the error of closure. The permissible limit of closing error depends upon the nature of the work for which the leveling is to be done. The permissible closing error may be expressed as, 

Where,

E = the error in metres,

C = the constant, the value of which depends upon the type of instrument, nature of the country, atmospheric conditions and care and judgement of the level man  

D = distance in kilometre

• Rough levelling: 
• Ordinary levelling: 
• Accurate levelling: 
• Precise levelling: 

Explanation:

Given Link length =  ft

Chain has 16 Links ⇒ Total Length = 16 ×  = 33 ft

Revenue Chain:

The revenue chain is 33 ft long and consists of 16 links. 

Additional InformationThese chains are mainly used for measuring field in cadastral survey.

Concept:

Dip:

• It is the inclination of the magnetic needle with the horizontal. The dip is zero at the equator and the needle will remain horizontal.
• At a place near 70° north latitude and 96° west longitude, the dip will be 90°. This area is called the magnetic north pole. Similarly, near the south magnetic pole, the dip is 90°.

​
Declination: 

• It is the angle between the magnetic and geographic meridians or the angle in the horizontal plane between magnetic north and true north.

Explanation:

Explanation:

The difference (degree) in the magnitude of the fore bearing and back bearing of any line is 180° or if the difference is exactly 180°, the two stations may be considered as not affected by local attraction.

For regular hexagon, Sum of interior angles = (n - 2)180° 

Sum of interior angles = (6 - 2)180° = 720° 

Each interior angle =  = 120° 

Back bearing = 180° + Fore bearing = 180° + 36°45' = 216°45'

∴ Fore bearing of BC = 216°45' - 120° = 96°45'

Explanation:

Leveling staff:

• It is a self-reading graduated wooden rod having a rectangular cross-section. The lower end of the rod is shod with metal to protect it from wear and usually point of zero measurements from which the graduations are numbered.
• Staff are either solid (having a single piece of 3-meter height)  or folding staff (of 4-meter height into two or three pieces)
• The least count of a leveling staff is 5 mm.
• Leveling used with a leveling instrument to determine the difference in height between points or heights of points above a vertical datum.

Important Points

Due earth refraction, line of sight bends towards the earth, therefore we noted less value of staff of reading i.e. Decrease in staff reading. To understand this refers the following figure:

Instrument

SR₁ = Staff reading without refraction

SR₂ = staff reading with refraction (Noted value)

It is clear from above that: SR₂ 1

∴ Staff reading reduces due to refraction.

Important Point:

Concept:

Vernier Scale is used to measure the fractional part of the least division marked on the main scale.

Types of Vernier Scale

• Direct Vernier:
  • N divisions of the direct vernier = (N - 1) division of the main scale
• Retrograde Vernier:
  • N divisions of the retrograde vernier = (N + 1) division of the main scale
• Extended Vernier:
  • N divisions of the extended vernier = (2 N - 1) division of the main scale

Calculation:

N divisions of the extended vernier = (2 N - 1) division of the main scale

8 divisions of the extended vernier = (2 × 8 - 1) division of the main scale

8 divisions of the extended vernier = 15 division of the main scale