Idaho Professional Land Surveyor
Examination Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. A closed traverse has a measured angular misclosure that exceeds the
allowable tolerance for the survey specification. What is the most
appropriate first action?
A. Distribute the error automatically by the compass rule
B. Investigate the observations and identify possible blunders before
adjustment
C. Increase all measured distances proportionally
D. Ignore the misclosure if the final coordinates appear reasonable
Rationale: A misclosure exceeding tolerance should be investigated before any
mathematical adjustment. Adjustment procedures are not intended to conceal
observational blunders.
2. In a least-squares adjustment, an observation with a smaller standard
deviation generally receives what relative weighting?
,A. Lower weight
B. Zero weight
C. Higher weight
D. The same weight as every observation
Rationale: In weighted least squares, observations considered more precise
receive greater weight, commonly proportional to the inverse of variance.
3. A surveyor occupies a point with known coordinates and observes a
backsight with known coordinates. The primary purpose of the backsight is
to establish:
A. Instrument height
B. Vertical datum
C. Orientation or direction reference
D. Atmospheric pressure
Rationale: A known backsight provides a reference direction from the occupied
control point, allowing observed horizontal angles to be related to the
coordinate system.
4. Two independent GPS observations of the same point produce horizontal
coordinates that differ significantly. Which issue should be investigated
first?
A. Whether the point has a new legal description
B. Observation quality, satellite geometry, reference frame, and processing
settings
C. Whether the plat uses a north arrow
D. Whether the property owner agrees with the coordinates
Rationale: GNSS discrepancies can result from multipath, poor satellite
geometry, reference-frame differences, antenna setup, or processing problems.
5. Which adjustment method is generally most appropriate when
observations have different estimated precisions and are statistically
independent?
,A. Bowditch adjustment
B. Transit adjustment
C. Weighted least-squares adjustment
D. Arbitrary coordinate averaging
Rationale: Weighted least squares allows observations to contribute according
to their estimated precision and provides statistical measures of the adjustment.
6. A total station measures slope distance and vertical angle. To obtain
horizontal distance, the surveyor must account for:
A. Only prism constant
B. Only atmospheric pressure
C. The vertical component represented by the measured vertical angle
D. Magnetic declination only
Rationale: Horizontal distance is obtained by resolving the slope distance into its
horizontal component using the appropriate zenith or vertical angle convention.
7. A line has an azimuth of 235°00′00″. What is its back azimuth?
A. 55°00′00″
B. 125°00′00″
C. 55°00′00″
D. 305°00′00″
Rationale: Because the forward azimuth exceeds 180°, subtract 180°: 235° −
180° = 55°.
8. A boundary survey discovers an original monument that conflicts with a
later mathematical subdivision calculation. Which evidence generally
deserves greater consideration?
A. The mathematical calculation
B. The newest survey
C. The original monument and evidence of the original survey
D. The shortest measured distance
, Rationale: Boundary retracement generally seeks to locate the original
boundaries rather than redesign them. Original monuments and reliable
evidence of the original survey can control over later calculations.
9. Which statement best describes a datum?
A. A property deed
B. A field-book notation
C. A reference framework from which measurements or positions are
determined
D. A surveyor's personal opinion
Rationale: A datum provides the reference framework for horizontal, vertical, or
geodetic positions.
10.A differential leveling loop begins and ends on the same benchmark. The
resulting elevation difference is not zero. This difference is called:
A. Index error
B. Collimation error
C. Leveling misclosure
D. Scale factor
Rationale: A closed leveling loop should return to the starting elevation. The
difference between computed and known closing elevation is the leveling
misclosure.
11.In differential leveling, why are balanced backsight and foresight distances
desirable?
A. They increase rod length
B. They eliminate all random errors
C. They help cancel systematic effects such as collimation error and some
curvature/refraction effects
D. They eliminate the need for benchmarks