Q16. Level surface in terms of leveling is a:
Difficulty: Easy
A. vertical surface
B. horizontal surface
C. curved surface
D. datum surface
Correct Answer: C. curved surfaceSolution:A level surface is a curved surface concentric with the mean spheroidal surface of the Earth. Every point on it is perpendicular to the local plumb line. It is NOT flat (horizontal = tangent plane at one point) — the two surfaces diverge with increasing distance.
Q17. For which application in leveling is an inverted staff reading most suitable?
Difficulty: Easy
A. Levelling across a wall
B. Levelling across intervening high or low ground
C. Levelling across a steep slope
D. Levelling across a lake
Correct Answer: A. Levelling across a wallSolution:An inverted staff is used when the target (e.g., underside of a lintel, bridge soffit, ceiling) is above the instrument's line of sight. The staff is held upside down against the overhead surface and the reading is treated as negative. Across a wall means measuring the overhead lintel or slab underside.
Q18. Roof as BM: inverted staff = 3.500 m, RL of BM = 100 m, staff at P = 1.200 m. Find RL of P.
Difficulty: Medium
A. 102.3 m
B. 95.3 m
C. 97.7 m
D. 104.7 m
Correct Answer: B. 95.3 mSolution:Inverted BS = −3.500 m. HI = 100 + (−3.500) = 96.50 m. RL(P) = 96.50 − 1.200 = 95.3 m. The instrument line of sight is 3.5 m below the roof (ceiling). Point P is a further 1.2 m below the instrument, giving 95.3 m.
Q19. Which is INCORRECT about Height of Instrument (HI) in levelling?
Difficulty: Medium
A. HI never changes while recording fore sights
B. HI generally changes before recording back sights
C. HI never changes while recording intermediate sights
D. HI never changes after recording back sights
Correct Answer: D. HI never changes after recording back sightsSolution:Statement D is INCORRECT. HI is constant within a single instrument setup, but it changes every time the instrument is relocated and a new BS is taken. HI does NOT remain constant permanently after one BS — each new instrument setup establishes a completely new HI.
Q20. During levelling, backsight at A was greater than foresight at B. Which is correct?
Difficulty: Easy
A. Height of instrument is required to know which point is higher
B. Elevation of B is more than that of A
C. Elevation of A is more than that of B
D. Either A or B can have higher elevation
Correct Answer: B. Elevation of B is more than that of ASolution:RL(B) = RL(A) + BS − FS. If BS > FS, then RL(B) > RL(A). A large staff reading at A means A is low; a small staff reading at B means B is close to the line of sight, hence higher. So B has higher elevation.
Q21. Closed traverse: AB FB=10°20′, BB=190°20′; BC FB=155°30′, BB=336°30′; CA FB=290°00′, BB=112°00′. Total error is:
Difficulty: Hard
A. −1°0'
B. +1°0'
C. −3°0'
D. +3°0'
Correct Answer: D. +3°00'Solution:AB: BB − FB = 180°00' → A and B are free of local attraction. FB(BC) = 155°30' is correct. True BB(BC) = 335°30'; observed = 336°30'; error at C = +1°. Corrected FB(CA) = 290° − 1° = 289°; True BB(CA) = 109°; observed = 112°. Total error = +3°00'.
Q22. Which variations in magnetic declination are correctly paired? (1) Diurnal-Temperature (2) Secular-Earthquakes (3) Irregular-Magnetic storms
Difficulty: Medium
A. 1, 2 and 3
B. Only 1 and 2
C. Only 2 and 3
D. Only 1 and 3
Correct Answer: D. Only 1 and 3Solution:Pairing 2 is wrong: secular variation is caused by long-term changes in Earth's molten iron core (~250-year cycle), NOT earthquakes. Earthquakes cause irregular variation. Pairings 1 (diurnal ← solar/temperature) and 3 (irregular ← magnetic storms) are correct.
Q23. If R is horizontal distance and d is diameter of Earth, curvature correction is:
Difficulty: Medium
A. d²/2R
B. d³/2R
C. d&sup4;/R
D. d²/4R
Correct Answer: A. d²/2RSolution:Standard derivation: Cc = D²/(2R) where D = distance and R = Earth's radius. With the question's unusual notation (R = horizontal distance, d = Earth's diameter), the mathematical relationship D²/(2R) corresponds to option (a). The exam board officially accepted option A.
Q24. Levelling in which staff readings AND the distance between points is required is called:
Difficulty: Easy
A. fly levelling
B. profile levelling
C. auto levelling
D. trigonometric levelling
Correct Answer: B. profile levellingSolution:Profile (longitudinal) levelling plots the ground elevation along a route. It records both the elevation (staff readings) and the chainage (horizontal distance) at each station so the longitudinal section can be drawn. Fly levelling only needs staff readings; differential levelling needs only staff readings.
Q25. Pipe conveys 0.8 m³/s from source RL=92 m to reservoir RL=108 m. Static head required is:
Difficulty: Medium
A. 12 m
B. 14 m
C. 16 m
D. 18 m
Correct Answer: C. 16 mSolution:Static head = delivery RL − source RL = 108.00 − 92.00 = 16 m. Static head depends only on the vertical elevation difference. Pipe diameter, flow rate, pipe length, and friction factor are irrelevant to static head (they affect friction and velocity heads).
Q26. The dumpy level is most suitable for levelling survey:
Difficulty: Easy
A. in forest areas
B. on flat terrain
C. on a steep slope
D. in hilly areas
Correct Answer: B. on flat terrainSolution:The dumpy level's telescope is rigidly fixed to its levelling head — it cannot tilt. This makes it ideal for flat terrain where long sight distances are achievable without the instrument being pointed up or down. On steep or hilly ground, instrument moves must be frequent and a rigid telescope is impractical.
Q27. RL of A = 100 m, BS at A = 2.00 m, reading at change point = 1.5 m. Find RL of change point.
Difficulty: Easy
A. 98.5 m
B. 100.5 m
C. 102 m
D. 103.5 m
Correct Answer: B. 100.5 mSolution:HI = RL(A) + BS = 100 + 2.00 = 102 m. The reading at the change point before shifting = FS = 1.5 m. RL(CP) = HI − FS = 102 − 1.5 = 100.5 m. Note: 102 m is the HI, not the RL of the CP.
Q28. Which test makes the line of sight perpendicular to the horizontal axis?
Difficulty: Medium
A. Azimuth test
B. Cross hair ring test
C. Spire test
D. Vertical arc test
Correct Answer: A. Azimuth testSolution:The Azimuth test ensures the line of collimation (line of sight) is perpendicular to the horizontal (transit) axis. The Spire test makes the horizontal axis perpendicular to the vertical axis. The Cross hair ring test ensures the vertical crosshair is in a plane perpendicular to the horizontal axis.
Q29. Differential levelling: A to TP1 BS=2.024, FS=1.420; TP1 to TP2 BS=1.986, FS=2.100. RL(A)=240.000. Find RL of TP2.
Difficulty: Medium
A. 242.024 m
B. 241.202 m
C. 240.604 m
D. 240.490 m
Correct Answer: D. 240.490 mSolution:Arithmetic check: ΣBS = 2.024 + 1.986 = 4.010 m; ΣFS = 1.420 + 2.100 = 3.520 m. Last RL − First RL = ΣBS − ΣFS = 4.010 − 3.520 = 0.490 m. RL(TP2) = 240.000 + 0.490 = 240.490 m.
Q30. In a levelling survey, the first staff reading after shifting the instrument and the last reading before shifting are respectively:
Difficulty: Easy
A. back sight and intermediate sight
B. intermediate sight and back sight
C. back sight and fore sight
D. foresight and back sight
Correct Answer: C. back sight and fore sightSolution:First reading after instrument setup = Back Sight (BS) on a known/change point, to establish HI. Last reading before instrument is moved = Fore Sight (FS) on the next change point, to determine its RL. The traverse always starts with BS and closes with FS.
