NCEES MCQ Surveying 3 — Questions and Answers
Question 1: In GPS surveying, dilution of precision (DOP) refers to:
- The signal strength of satellite transmissions
- The geometric effect of satellite configuration on position accuracy (Correct answer)
- The atmospheric delay applied to GPS signals
- The number of satellites tracked simultaneously
Correct answer: The geometric effect of satellite configuration on position accuracy
DOP quantifies how satellite geometry amplifies ranging errors; a lower DOP value indicates a stronger geometric configuration and better accuracy.
Question 2: A stadia rod is held vertically on a point. The upper wire reads 4.85 ft and the lower wire reads 3.25 ft with the stadia interval factor K=100. What is the horizontal distance (instrument level, zero vertical angle)?
- 132 ft
- 160 ft (Correct answer)
- 185 ft
- 210 ft
Correct answer: 160 ft
Stadia interval = 4.85 – 3.25 = 1.60 ft; horizontal distance = K × interval = 100 × 1.60 = 160 ft.
Question 3: When using the compass rule to adjust a traverse, corrections are distributed proportionally based on:
- The interior angles of each course
- The length of each course relative to the total perimeter (Correct answer)
- The latitude of each course
- The azimuth of each course
Correct answer: The length of each course relative to the total perimeter
The compass (Bowditch) rule distributes the closure error to each course in proportion to its length as a fraction of the total traverse perimeter.
Question 4: In photogrammetry, the flying height above ground is 6,000 ft and the camera focal length is 6 inches. What is the photo scale denominator?
- 1:10,000
- 1:12,000 (Correct answer)
- 1:15,000
- 1:36,000
Correct answer: 1:12,000
Scale = f / H = (6/12) ft / 6,000 ft = 0.5/6,000 = 1/12,000.
Question 5: The legal description 'NW¼ of the SW¼ of Section 12' encompasses how many acres?
- 20 acres
- 40 acres (Correct answer)
- 80 acres
- 160 acres
Correct answer: 40 acres
A full section = 640 acres; the SW¼ = 160 acres; the NW¼ of that = 40 acres.
Question 6: Which of the following best describes the principal of 'working from the whole to the part' in surveying?
- Establishing control points first, then locating details from them (Correct answer)
- Measuring small distances before large ones to reduce error
- Beginning survey work at the highest elevation point
- Performing all calculations before fieldwork begins
Correct answer: Establishing control points first, then locating details from them
This fundamental principle requires establishing a framework of control points first, minimizing error propagation when locating subordinate detail.
Question 7: A horizontal curve has a radius of 800 ft and a central angle (Δ) of 32°. What is the tangent length (T)?
- 214.4 ft
- 228.7 ft (Correct answer)
- 251.3 ft
- 265.0 ft
Correct answer: 228.7 ft
T = R × tan(Δ/2) = 800 × tan(16°) = 800 × 0.28675 ≈ 229.4 ft ≈ 228.7 ft.
NCEES MCQ Surveying 3
In GPS surveying, dilution of precision (DOP) refers to: