The horizontal glass in an optical square is ............

The strength of fix is poor when ............

The survey a small area which one of the most important operation for setting up the plane table is ............

Magnetic bearing of a survey line at any place ............

In the surveying telescope, diaphragm is held ............

Correction for curvature for a distance of 1 km = ............

The distance between steps for measuring downhill to obtain better accuracy ............

The representation of general topography of a very flat terrain is possible only ............

An 'are' is the unit of area of a square of side ............