SMQT Introduction to Surveying 3 — Questions and Answers
Question 1: What is 'differential leveling' used to determine?
- Horizontal distances between two points
- Elevation differences between two or more points (Correct answer)
- Deflection angles along a traverse
- Magnetic declination at a site
Correct answer: Elevation differences between two or more points
Differential leveling uses a level instrument and rod to determine the difference in elevation between points.
Question 2: In a survey traverse, 'closure error' refers to:
- The difference between measured and record distances
- The failure of a traverse to return exactly to its starting point (Correct answer)
- An error in reading a compass bearing
- The gap between two property monuments
Correct answer: The failure of a traverse to return exactly to its starting point
Closure error is the discrepancy between the computed and actual end point of a closed traverse, indicating accumulated measurement errors.
Question 3: What is the magnetic declination?
- The angle between true north and magnetic north at a given location (Correct answer)
- The dip angle of the Earth's magnetic field
- The variation in compass readings due to local iron deposits
- The difference between grid north and true north
Correct answer: The angle between true north and magnetic north at a given location
Magnetic declination is the horizontal angle between geographic (true) north and magnetic north, which varies by location and changes over time.
Question 4: Which of the following best describes a 'benchmark' in surveying?
- A reference line used to measure horizontal distances
- A permanent point of known elevation used as a vertical reference (Correct answer)
- A monument marking a property corner
- A standard measurement used to calibrate instruments
Correct answer: A permanent point of known elevation used as a vertical reference
A benchmark is a stable, permanent marker of precisely known elevation that serves as a reference for leveling surveys.
Question 5: The 'rod reading' in differential leveling is the value observed on the:
- Horizontal circle of the level instrument
- Stadia rod held vertically at a survey point (Correct answer)
- Tape stretched between two monuments
- Vertical circle of the theodolite
Correct answer: Stadia rod held vertically at a survey point
The rod (or level rod) is a graduated staff held vertically at a point, and its reading through the level telescope gives the height of the instrument above that point.
Question 6: What is 'photogrammetry' in the context of surveying?
- Measuring distances using light pulses
- Extracting measurements and maps from photographs (Correct answer)
- Surveying using radio signal triangulation
- Determining depths using sonar imagery
Correct answer: Extracting measurements and maps from photographs
Photogrammetry is the science of obtaining reliable measurements and maps from photographs, commonly using aerial or drone imagery.
Question 7: In surveying, 'staking out' a building refers to:
- Placing boundary monuments around a property
- Marking the planned position of a structure on the ground (Correct answer)
- Setting elevation benchmarks for a construction project
- Flagging existing utilities before excavation
Correct answer: Marking the planned position of a structure on the ground
Staking out (or layout surveying) translates the designed positions from plans to physical marks on the ground for construction guidance.
SMQT Introduction to Surveying 3
What is 'differential leveling' used to determine?