Identify the correct characteristic feature of scale chosen to draw profile of ground using profile leveling data.
- AVertical distances are exaggerated as compared to horizontal distances.Correct
- BBoth horizontal and vertical distances are always plotted to 1 : 1 scale.
- CHorizontal distances are exaggerated as compared to vertical distances.
- DBoth horizontal and vertical distances are plotted to the same scale.
Solution
Concept
In a profile drawing, the vertical scale is made larger than the horizontal scale so that small changes in ground level are clearly seen.
Step-by-step solution
1. Profile levelling gives reduced levels at chainages along a line. 2. Horizontal distances are large (hundreds of metres). Level differences are small (a few metres). 3. If both used the same scale, the ground would look almost flat. 4. So the vertical scale is exaggerated, usually about 10 times the horizontal scale. 5. Answer is A.
Explanation
Ground level changes are very small compared to horizontal lengths. To show these changes clearly, vertical distances are drawn to a larger (exaggerated) scale than horizontal distances. A common ratio is about 10:1.
Why the other options are wrong
B: A 1:1 (full size) scale is impossible for long profiles. C: Horizontal distances are not exaggerated. The vertical ones are. D: The same scale would make the profile look flat and level changes hard to see.
Shortcut
Profile = vertical exaggeration (vertical scale about 10 × horizontal).
Common mistake
Thinking that both directions must use the same scale like a normal map.
Correct answer: A) Vertical distances are exaggerated as compared to horizontal distances.