Illinois Fundamentals of Surveying
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. Which surveying principle is most important when establishing a
network of control points?
A. Measure only angles because distances are secondary
B. Begin with the least accurate observations
C. Establish reliable control and make independent checks on
measurements
D. Avoid redundant observations to reduce field time
Answer: C
Rationale: A dependable surveying network should be based on
accurately established control and should contain sufficient
redundancy to detect blunders and evaluate measurement quality.
Independent checks are essential because a single unchecked
observation can introduce an error throughout the survey.
2. A horizontal distance is measured between two points, but the
measurement is taken along a sloping surface. What must be done
to obtain the horizontal distance?
A. Reduce the slope distance using the vertical angle or elevation
difference
B. Add the vertical difference to the slope distance
,C. Multiply the slope distance by the vertical angle
D. Divide the slope distance by the elevation difference
Answer: A
Rationale: A slope distance is longer than its horizontal projection
unless the line is level. The horizontal distance can be calculated from
the slope distance and zenith or vertical angle. Accurate reduction is
necessary whenever measured distances are to be used in horizontal
coordinate calculations.
3. Which instrument is primarily designed to measure horizontal and
vertical angles electronically?
A. Automatic level
B. Steel tape
C. Planimeter
D. Theodolite or total station
Answer: D
Rationale: A theodolite measures horizontal and vertical angles, while
a modern total station combines angular measurement with electronic
distance measurement and data collection. An automatic level is
primarily intended for determining differences in elevation rather than
measuring both horizontal and vertical angles.
4. In differential leveling, the line of sight is established by an
instrument that is approximately horizontal. What is the principal
purpose of the backsight?
A. To determine the azimuth of the survey
B. To establish the instrument height relative to a known elevation
C. To determine the horizontal distance between turning points
D. To measure the magnetic declination
,Answer: B
Rationale: In differential leveling, the backsight is normally taken on
a point of known elevation. Adding the backsight reading to the known
elevation gives the height of instrument. Subsequent foresights can
then be used to calculate elevations of unknown points.
5. Which type of error is generally caused by a mistake such as
recording 72.15 ft as 27.15 ft?
A. Random error
B. Systematic error
C. Atmospheric error
D. Blunder
Answer: D
Rationale: A blunder is a gross mistake resulting from human or
procedural error. Examples include incorrect transcription,
misreading a rod, occupying the wrong point, or entering an incorrect
instrument value. Blunders should be detected through independent
checks and rejected or corrected rather than statistically distributed as
ordinary measurement error.
6. What is the primary function of a benchmark in surveying?
A. To provide a point of known elevation
B. To provide a known magnetic bearing
C. To establish the property owner's name
D. To provide a known scale factor only
Answer: A
Rationale: A benchmark is a permanent or semi-permanent reference
point whose elevation has been established relative to a specified
, vertical datum. Benchmarks provide the starting or checking
elevations for leveling and other elevation-related surveying work.
7. If a horizontal angle is measured repeatedly under similar
conditions and the observations differ slightly, the differences are
most likely due to:
A. A legal description error
B. A boundary monument
C. Random measurement error
D. A datum transformation
Answer: C
Rationale: Random errors vary in magnitude and sometimes in sign
from one observation to another. They arise from small unavoidable
variations in instrument setup, pointing, environmental conditions,
and observer judgment. Repeated observations can help estimate and
reduce their effect.
8. Which coordinate system uses a pair of perpendicular axes to
describe the position of a point?
A. Polar-only system
B. Cartesian coordinate system
C. Astronomical coordinate system
D. Magnetic coordinate system
Answer: B
Rationale: The Cartesian system locates a point by its coordinates
relative to perpendicular axes. In surveying, northing and easting
coordinates are commonly used in a rectangular coordinate
framework, allowing distances, directions, areas, and other spatial
relationships to be computed mathematically.
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which surveying principle is most important when establishing a
network of control points?
A. Measure only angles because distances are secondary
B. Begin with the least accurate observations
C. Establish reliable control and make independent checks on
measurements
D. Avoid redundant observations to reduce field time
Answer: C
Rationale: A dependable surveying network should be based on
accurately established control and should contain sufficient
redundancy to detect blunders and evaluate measurement quality.
Independent checks are essential because a single unchecked
observation can introduce an error throughout the survey.
2. A horizontal distance is measured between two points, but the
measurement is taken along a sloping surface. What must be done
to obtain the horizontal distance?
A. Reduce the slope distance using the vertical angle or elevation
difference
B. Add the vertical difference to the slope distance
,C. Multiply the slope distance by the vertical angle
D. Divide the slope distance by the elevation difference
Answer: A
Rationale: A slope distance is longer than its horizontal projection
unless the line is level. The horizontal distance can be calculated from
the slope distance and zenith or vertical angle. Accurate reduction is
necessary whenever measured distances are to be used in horizontal
coordinate calculations.
3. Which instrument is primarily designed to measure horizontal and
vertical angles electronically?
A. Automatic level
B. Steel tape
C. Planimeter
D. Theodolite or total station
Answer: D
Rationale: A theodolite measures horizontal and vertical angles, while
a modern total station combines angular measurement with electronic
distance measurement and data collection. An automatic level is
primarily intended for determining differences in elevation rather than
measuring both horizontal and vertical angles.
4. In differential leveling, the line of sight is established by an
instrument that is approximately horizontal. What is the principal
purpose of the backsight?
A. To determine the azimuth of the survey
B. To establish the instrument height relative to a known elevation
C. To determine the horizontal distance between turning points
D. To measure the magnetic declination
,Answer: B
Rationale: In differential leveling, the backsight is normally taken on
a point of known elevation. Adding the backsight reading to the known
elevation gives the height of instrument. Subsequent foresights can
then be used to calculate elevations of unknown points.
5. Which type of error is generally caused by a mistake such as
recording 72.15 ft as 27.15 ft?
A. Random error
B. Systematic error
C. Atmospheric error
D. Blunder
Answer: D
Rationale: A blunder is a gross mistake resulting from human or
procedural error. Examples include incorrect transcription,
misreading a rod, occupying the wrong point, or entering an incorrect
instrument value. Blunders should be detected through independent
checks and rejected or corrected rather than statistically distributed as
ordinary measurement error.
6. What is the primary function of a benchmark in surveying?
A. To provide a point of known elevation
B. To provide a known magnetic bearing
C. To establish the property owner's name
D. To provide a known scale factor only
Answer: A
Rationale: A benchmark is a permanent or semi-permanent reference
point whose elevation has been established relative to a specified
, vertical datum. Benchmarks provide the starting or checking
elevations for leveling and other elevation-related surveying work.
7. If a horizontal angle is measured repeatedly under similar
conditions and the observations differ slightly, the differences are
most likely due to:
A. A legal description error
B. A boundary monument
C. Random measurement error
D. A datum transformation
Answer: C
Rationale: Random errors vary in magnitude and sometimes in sign
from one observation to another. They arise from small unavoidable
variations in instrument setup, pointing, environmental conditions,
and observer judgment. Repeated observations can help estimate and
reduce their effect.
8. Which coordinate system uses a pair of perpendicular axes to
describe the position of a point?
A. Polar-only system
B. Cartesian coordinate system
C. Astronomical coordinate system
D. Magnetic coordinate system
Answer: B
Rationale: The Cartesian system locates a point by its coordinates
relative to perpendicular axes. In surveying, northing and easting
coordinates are commonly used in a rectangular coordinate
framework, allowing distances, directions, areas, and other spatial
relationships to be computed mathematically.
