The intersection of curved surface with a plane passing through the centre of the earth will form a line continuous around the earth, and that portion of line is called as_______ line.
level
A horizontal line is a line tangent to a level surface at a particular point. A level surface is a curved surface that is everywhere perpendicular to the direction of gravity (the plumb line). A line lying within a level surface is called a level line.
Important Questions from Levelling
Calculate the true reduced level (m) of a point A after correcting the refraction and curvature. The staff reading at the point taken from an instrument set at a distance of 2 km from the point A is 2.56 m. The staff reading from the same station on a bench mark of reduced level is 100 m is 1.34 m.
The dumpy level is most suitable for levelling survey:
Levelling in which staff and readings and the distance between the points is required is called:
In permanent adjustment of levels, two peg test is done to correct:
In a levelling work, seven readings were taken with a level as - 1.42, 1.57, 0.765, 1.11, 1.95, 2.9, and 1.825 m. If the instrument was shifted after the third and fifth readings, the readings recorded under the fore sight column will be:
