Q16. Contour interval on a map sheet denotes:
Difficulty: Easy
A. Vertical distance of contour lines above the datum plane
B. Vertical distance between two successive contour lines
C. Slope distance between two successive contour lines
D. Horizontal distance between two successive contour lines
Correct Answer: B. Vertical distance between two successive contour linesSolution:The contour interval (CI) is the constant vertical elevation difference between any two consecutive contour lines on a map. Option A describes RL (absolute elevation), Option C includes slope components, Option D describes the horizontal equivalent (HE) which is variable — none of these is the CI.
Q17. The representation of general topography of a very flat terrain is possible only by:
Difficulty: Medium
A. Drawing contours at large interval
B. Drawing contours at small interval
C. Giving spot levels at large interval
D. Giving spot levels to salient features at close interval
Correct Answer: D. Giving spot levels to salient features at close intervalSolution:On very flat ground, even a small CI produces contours hundreds of metres apart — conveying almost no useful information. Instead, spot levels at salient features (road crowns, drain lips, low bunds) at close intervals capture the subtle micro-relief that contours cannot represent on flat terrain.
Q18. A series of closed contour lines on the map with lower to higher value inside them, represents a:
Difficulty: Easy
A. Hill
B. Ridge
C. Depression
D. Steep slope
Correct Answer: A. HillSolution:Closed contour loops with values increasing inward (lower outside, higher inside) indicate a hill or peak — elevation rises toward the centre. The opposite (values decreasing inward) would represent a depression or pond.
Q19. In a section AA of the map, closely spaced contour lines represent:
Difficulty: Easy
A. Steep slope
B. Flat slope
C. Uniform slope
D. Ridge
Correct Answer: A. Steep slopeSolution:Closely spaced contours mean a large elevation change (fixed CI) occurs over a short horizontal distance — this is by definition a steep slope. HE = CI / tan(slope): small HE means large slope angle. Flat terrain has widely-spaced contours; uniform slope means parallel (not necessarily close) contours.
Q20. The vertical distance between any two consecutive contours is called:
Difficulty: Easy
A. Vertical equivalent
B. Horizontal equivalent
C. Contour interval
D. Contour gradient
Correct Answer: C. Contour intervalSolution:The contour interval is the constant vertical (elevation) difference between consecutive contour lines. Horizontal equivalent is the plan distance between contours (variable with slope). Contour gradient is the slope of the ground along a contour. “Vertical equivalent” is not a standard surveying term.
Q21. The contour lines can cross one another on map only in the case of:
Difficulty: Medium
A. A vertical cliff
B. A valley
C. A ridge
D. An overhanging cliff
Correct Answer: D. An overhanging cliffSolution:At an overhanging cliff the rock face leans beyond the vertical, so the same plan (x, y) position corresponds to two different elevations. Contours of those two elevations therefore cross on the map. At a vertical cliff, contours merge (coincide) but do not cross. Ridges and valleys produce no contour crossing at all.
Q22. The best method of interpolation of contour is by:
Difficulty: Medium
A. Estimation
B. Graphical mean
C. Computation
D. All of these
Correct Answer: C. ComputationSolution:Arithmetical computation gives the most accurate contour position between two spot levels by proportional calculation: distance from lower point = (contour RL − lower RL) × total distance ÷ total RL difference. Estimation relies on judgment; graphical is less precise than calculation; they are not equally good.
Q23. A series of closely spaced contour lines represents:
Difficulty: Easy
A. Steep slope
B. Gentle slope
C. Uniform slope
D. Plane surface
Correct Answer: A. Steep slopeSolution:Closely spaced contours mean the fixed CI is achieved over a small horizontal distance (small HE) — indicating a large slope angle, i.e. a steep slope. Gentle slope has widely spaced contours; uniform slope has parallel (not necessarily close) contours; plane surface has widely spaced or absent contours.
Q24. Which method of contouring is most suitable for hilly terrains?
Difficulty: Easy
A. Cross section method
B. Direct method
C. Square method
D. Tacheometric method
Correct Answer: D. Tacheometric methodSolution:The tacheometric method allows the surveyor to measure distances and elevations optically from one instrument station using radial sights, covering a wide hilly area without physically traversing the steep terrain. Cross-section and square methods require regular traverses; direct method is slow on hills.
Q25. Which of the following contour represents either hills or ponds?
Difficulty: Easy
A. Contour having concentric circles
B. Closely placed contour
C. Distant contour
D. Parallel contour
Correct Answer: A. Contour having concentric circlesSolution:Concentric closed loops (circles) indicate an isolated point feature — a hill if values increase inward (toward a summit), or a pond/depression if values decrease inward (toward a lowest point). Closely-placed contours = steep slope; distant contours = gentle slope; parallel contours = uniform slope.
Q26. Which of the following statements are CORRECT for contour map?
1. Parallel contour shows uniform slope.
2. Very closed contour shows steep slope.
3. Very closed contour shows flat area.
4. Two contours at different elevation cut at right angle.
Difficulty: Hard
A. 1, 2 and 4
B. 1 and 2
C. 1, 3 and 4
D. 2 and 4
Correct Answer: B. 1 and 2Solution:Statements 1 (parallel = uniform slope) and 2 (closely-spaced = steep slope) are both correct. Statement 3 is false — closely-spaced means steep, not flat. Statement 4 is false — two contours of different elevations never cut at right angles; they only cross at overhanging cliffs, not at 90°.
Q27. Which of the following statement is TRUE for the linear reservoir?
Difficulty: Hard
A. Storage is proportional to inflow discharge
B. Storage is proportional to outflow discharge
C. Storage is proportional to square of inflow discharge
D. Storage is proportional to square of outflow discharge
Correct Answer: B. Storage is proportional to outflow dischargeSolution:A linear reservoir is defined by S = k × Q, where S is storage and Q is outflow discharge. Storage is directly (linearly) proportional to outflow — not inflow, and not Q². The constant k has units of time and represents the mean residence time of water in the reservoir.
Q28. In which of the following condition two contour lines intersect each other?
Difficulty: Medium
A. Hills
B. Overhanging cliff
C. Steep slope
D. Uniform slope
Correct Answer: B. Overhanging cliffSolution:Two contour lines can only cross where one plan position corresponds to two different ground elevations. This occurs at an overhanging cliff (and caves), where the overhang extends beyond the vertical. Hills, steep slopes, and uniform slopes all have one elevation per plan position — no crossing possible.
Q29. For more precise representation of the terrain relief, the contour interval should:
Difficulty: Easy
A. Decrease continuously
B. Increase continuously
C. Be larger
D. Be smaller
Correct Answer: D. Be smallerSolution:A smaller contour interval means more contour lines are drawn for the same terrain, capturing finer elevation variations and subtle features that a large CI would miss. More lines = more information = more precise representation. A large CI skips minor undulations and gives a coarser picture.
Q30. The direction of steepest slope on a contour is:
Difficulty: Easy
A. Along the contour
B. At an angle of 45° to the contour
C. At right angles to the contour
D. None of these
Correct Answer: C. At right angles to the contourSolution:Moving along a contour incurs zero elevation change (zero slope). Maximum elevation gain per unit horizontal distance occurs when moving perpendicular to the contour — the full CI is gained over the minimum HE. This direction (90° to the contour) is the steepest slope direction at every point.
