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WorksheetsDAY 48 WORKSHEET LSGD (Levelling , Contouring)
Total questions: 15
Worksheet time: 11mins
Mean Sea Level used for GTS Benchmarks is obtained by analyzing tidal data over —
10 years
16 years
19 years
50 years
Which condition ensures that the line of collimation remains horizontal during sighting?
Vertical axis ⟂ Bubble axis
Bubble axis ∥ Line of collimation
Plumb line ∥ Level line
Line of collimation ⟂ Telescope axis
Which sight reading can NEVER be taken on a point of known elevation?
Back sight
Intermediate sight
Fore sight
Check sight
Which levelling instrument allows precise bubble centering before each reading using a tilting screw?
Dumpy level
Y-Level
Tilting level
Auto level
If contour lines cross a valley, their V-shape will always point —
Upstream
Downstream
To the right
To the left
TRUE/FALSE
The horizontal line is always perpendicular to the plumb line at the point of observation (a)
TRUE/FALSE
Least count of self-reading levelling staff is 0.50 m (a)
Assertion (A): Dumpy levels have very stable permanent adjustments. Reason (R): The telescope is rigidly fixed to the spindle and cannot be rotated in the vertical plane.
A and R true; R explains A
A and R true; R does NOT explain A
A true; R false
A false; R true
A line that represents the direction of gravity at a point is called the (a) line.
The first staff reading taken after the instrument is set up is called (a) .
The plane tangential to the level surface at a point is known as the (a) plane.
The level surface is always (a) to the earth’s curvature.
A contour line joining points of equal elevation is plotted at a constant (a) interval.
MATCH THE FOLLOWING
Self-reading staff
Three-piece telescopic staff
Target/Philadelphia staff
Contains sliding target & vernier
Invar staff
Used in precise levelling
Folding staff
Folding type for short works
MATCH THE FOLLOWING
Datum
Reference for GTS network
Change point
Indicates shifting of instrument
Back sight
Plus sight
Permanent Bench Mark
Arbitrarily assumed elevation
