ETC ETC Surveying & Site Measurement 2 — Questions and Answers
Question 1: What is the purpose of a topographic survey?
- To map the elevations and contours of the land surface (Correct answer)
- To determine legal property boundaries
- To locate underground utilities
- To verify as-built dimensions
Correct answer: To map the elevations and contours of the land surface
A topographic survey measures and maps the elevation, slope, and surface features of the terrain using contour lines and spot elevations.
Question 2: In differential leveling, what does backsight (BS) refer to?
- A rod reading taken on a point of known elevation to establish the instrument height (Correct answer)
- A reading taken looking back toward the previous traverse station
- The final rod reading at the project endpoint
- A correction applied after instrument error is detected
Correct answer: A rod reading taken on a point of known elevation to establish the instrument height
A backsight is the first rod reading taken after setting up the level, placed on a benchmark to calculate the height of instrument.
Question 3: What instrument measures both horizontal and vertical angles and is commonly used for triangulation surveys?
- Theodolite (Correct answer)
- Auto level
- Hand level
- Planimeter
Correct answer: Theodolite
A theodolite precisely measures horizontal and vertical angles, making it essential for triangulation and traversing in engineering surveys.
Question 4: What is a rod reading in differential leveling?
- The graduated staff measurement read through the level to determine elevation difference (Correct answer)
- The iron pin driven to mark a survey corner
- The distance measured with a measuring tape
- The height of the instrument above the ground
Correct answer: The graduated staff measurement read through the level to determine elevation difference
A rod reading is the numeric value read on a graduated leveling rod through the telescope to compute elevation differences.
Question 5: What does cut and fill mean in site grading work?
- Excavating high areas and using that material to build up low areas (Correct answer)
- Cutting formwork and filling it with concrete
- Trimming survey stakes and filling in survey notes
- Removing topsoil and replacing it with compacted subbase
Correct answer: Excavating high areas and using that material to build up low areas
Cut and fill balances earthwork by excavating elevated areas and using the soil to raise lower areas to the design grade.
Question 6: Which coordinate system is commonly used on US construction drawings for specifying grid layout?
- State Plane Coordinate System (Correct answer)
- UTM (Universal Transverse Mercator)
- Geographic decimal degrees
- Local assumed coordinates only
Correct answer: State Plane Coordinate System
The State Plane Coordinate System is widely used in US construction and land surveying because it provides high accuracy within individual state zones.
ETC ETC Surveying & Site Measurement 2
What is the purpose of a topographic survey?