An instrument used for ranging is

To orient a plane table at a point with two inaccessible points, the method generally adopted is

The curvature of the earth is taken into consideration if the limit of survey is

The collimation method for obtaining the reduced levels of points does not provide a check on

If the back sight and fore sight distance are kept equal during levelling observations, then the effect of both refracti…

A surface which is normal to the direction of gravity at all points, as indicated by a plumb line, is known as

The height of instrument is equal to

Reading of the metric levelling staff can be taken accurately up to

Radiation plane table survey is the best suited when