Q1. Select the option that is correct regarding the following two statements, labelled as Assertion (A) and Reason (R), with respect to characteristic features of contour lines.
Assertion (A): A single contour cannot split into two lines.
Reason (R): A knife-edge ridge or depression does not occur in nature.
Difficulty: Hard
A. Both A and R are true, but R is not the correct explanation of A
B. A is true, but R is false
C. Both A and R are true and R is the correct explanation of A
D. A is false, but R is true
Correct Answer: C. Both A and R are true and R is the correct explanation of ASolution:A single contour cannot split into two because a perfect knife-edge ridge or depression does not exist in nature. Reason (R) correctly explains Assertion (A), making both true with R as the valid explanation.
Q2. Consider the following statements regarding horizontal equivalent and contour interval.
i. Horizontal equivalent between two contour lines is always constant.
ii. Horizontal equivalent may be zero for vertical cliff.
iii. Contour interval should be inversely proportional to the scale.
iv. For detailed design work, large contour interval is taken.
Which of the given statements are correct?
Difficulty: Hard
A. i and iv
B. i and iii
C. i and iii
D. ii and iii
Correct Answer: D. ii and iiiSolution:HE varies with slope (not constant), so statement i is false. HE = zero at a vertical cliff (ii is true). CI is inversely proportional to map scale (iii is true). Detailed design work requires a small, not large, CI (iv is false). Correct statements: ii and iii.
Q3. Which of the following statements regarding characteristics of contour lines is INCORRECT?
Difficulty: Medium
A. Contour lines of different elevation cannot cross each other.
B. Contour lines close to one another indicate a steep slope.
C. Contour lines of different elevations cannot intersect.
D. Contour lines of different elevations can unite to form one line only in the case of vertical cliff.
Correct Answer: C. Contour lines of different elevations cannot intersect.Solution:Statement C is incorrect because at an overhanging cliff or cave, contour lines of different elevations do cross each other. Options A and D are true (D distinguishes merging from crossing). Option B is also true. C is the incorrect statement.
Q4. Which of the following is a type of contouring method that can be effectively used in a hilly terrain by setting radial lines?
Difficulty: Easy
A. Vertical control method
B. Horizontal control method
C. Tacheometric method
D. Method of cross-section
Correct Answer: C. Tacheometric methodSolution:The tacheometric method uses radial lines of observation from a single instrument station, allowing the surveyor to locate many ground points by optical measurement without physical chaining. This is ideal for hilly terrain where traversing the ground is difficult.
Q5. Study the following statements with respect to characteristics of contour lines, and identify the correct option:
i. Contours do not pass through permanent structures such as buildings.
ii. Contours of different elevations cannot cross each other (caves and overhanging cliffs are the exceptions).
iii. A contour line must close upon itself, though not necessarily within the limits of the map.
Difficulty: Hard
A. ii and iii only
B. i, ii and iii
C. i and ii only
D. i and iii only
Correct Answer: B. i, ii and iiiSolution:All three are standard contour characteristics. Contours avoid permanent man-made structures (i); they only cross at caves/overhanging cliffs (ii); and every contour forms a closed loop, even if that loop extends beyond the map boundary (iii). All three statements are correct.
Q6. For locating contours by indirect method, two guide points A (Elevation 600 m) and B (Elevation 610 m) are established. The horizontal distance between the two points on the plan is 1 cm. Find the distance of the contour of 605 m from point A (on the plan).
Difficulty: Medium
A. 1 cm
B. 0.5 m
C. 1 m
D. 0.5 cm
Correct Answer: D. 0.5 cmSolution:Total elevation rise A to B = 10 m over 1 cm on plan. The 605 m contour is 5 m above A (half the total rise). By proportional interpolation: distance from A = (5/10) × 1 cm = 0.5 cm.
Q7. The RL of a point is 120 m and elevation of the instrument is 1 m. If a contour line of 119 m is to be plotted, the reading on the staff should be:
Difficulty: Medium
A. 1 m
B. 2 m
C. 0 m
D. 1.5 m
Correct Answer: B. 2 mSolution:Height of Instrument (HI) = point RL + instrument height = 120 + 1 = 121 m. Required staff reading = HI − contour elevation = 121 − 119 = 2 m.
Q8. Under which of the following circumstances can the contour lines of different elevations intersect each other?
Difficulty: Medium
A. Steep slope
B. Cave
C. River
D. Valley
Correct Answer: B. CaveSolution:Contour lines of different elevations can only cross where one plan (x, y) position corresponds to two different ground elevations. A cave or overhanging cliff creates this condition. A steep slope, river, and valley all have a single elevation at each plan position — so no crossing occurs.
Q9. While drawing a cross-section of a contour map, the following values were noted from point A to point B: 500 m, 400 m, 300 m, 200 m, 200 m, 300 m, 400 m, 500 m. Which cross-section would be drawn by using the above values?
Difficulty: Medium
A. Hill
B. Depression
C. Cliff
D. Steep slope
Correct Answer: B. DepressionSolution:The elevation profile decreases from 500 m at the edges to a minimum of 200 m at the centre, then rises again symmetrically. The lowest values are in the middle — this is the characteristic of a depression or valley, where the centre is lower than the surroundings.
Q10. Identify the correct statements:
i. Contour lines form sharp V-shaped curves across valley line, with the convex side of the curve towards the higher ground.
ii. Contour lines form U-shaped curves across valley line, with the convex side of the curve towards the higher ground.
iii. Contour lines form U-shaped curves across ridge line, with the concave side of the curve towards the higher ground.
iv. Contour lines form sharp U-shaped curves across ridge line, with the convex side of the curve towards the higher ground.
Difficulty: Hard
A. ii and iv
B. i and iii
C. ii and iii
D. i and iv
Correct Answer: B. i and iiiSolution:Valley contours form V-shapes with the convex (pointed) side facing upstream (i — true). Ridge contours form U-shapes with the concave (open) side facing the higher ground (iii — true). Statements ii and iv reverse the shapes and sides, making them false.
Q11. In case of uniform slope, the contour lines:
Difficulty: Easy
A. Widely space each other
B. Cross each other
C. Tend to parallel each other
D. Space very close to each other
Correct Answer: C. Tend to parallel each otherSolution:On a uniform slope the gradient is constant, so every pair of adjacent contours is separated by the same horizontal distance in the same direction. This produces equally-spaced, parallel contour lines. Wide/close spacing indicates gentle/steep slope, not uniformity; crossing is impossible on a normal slope.
Q12. Choose the INCORRECT characteristic of a contour from among the following.
Difficulty: Medium
A. Two contour lines touch in the case of a vertical cliff.
B. The direction of steepest slope is along the longest distance between the contours.
C. A watershed line crosses the contours at right angles.
D. In the direct method of contouring the contours are not interpolated.
Correct Answer: B. The direction of steepest slope is along the longest distance between the contours.Solution:Statement B is incorrect. The steepest slope is in the direction of the shortest horizontal distance between contours (perpendicular to them), not the longest. Options A, C, and D are all correct characteristics of contours.
Q13. Which shaped lines indicate the presence of a ridge?
Difficulty: Easy
A. S-shaped
B. L-shaped
C. U-shaped
D. Z-shaped
Correct Answer: C. U-shapedSolution:When contour lines cross a ridge they bend into U-shapes that open downslope, with the concave side facing the higher ground (the crest). Valley contours form V-shapes (convex toward high ground). A U-shape is the definitive visual signature of a ridge on a contour map.
Q14. Which of the following statements is/are true?
i. Contour lines cross valley line at 90°.
ii. Contour lines cross ridge line at 90°.
iii. Contour lines are widely spaced where ground has steep slope.
Difficulty: Hard
A. Both statements i and ii are true
B. Both statements i and iii are true
C. Both statements ii and iii are true
D. Only statement i is true
Correct Answer: A. Both statements i and ii are trueSolution:Both ridge lines and valley lines are lines of maximum slope and therefore perpendicular to contours at every crossing point (statements i and ii are true). Statement iii is false — closely (not widely) spaced contours indicate a steep slope. Widely spaced contours = gentle slope.
Q15. Which of the following features is shown by the parallel contour lines?
Difficulty: Easy
A. Flat plains
B. Hills
C. Steep slope
D. Uniform slope
Correct Answer: D. Uniform slopeSolution:A uniform slope has a constant gradient in one direction, giving every pair of adjacent contours the same horizontal separation and the same orientation — producing parallel, equally-spaced contour lines. Hills show concentric closed loops; steep slopes show close spacing; flat plains show very wide or absent contours.
