The instrument used for setting out an offset at a right angle, is called ............

A clinometer is used for ............

In locating the details of inaccessible objects visible at least from transit stations, the method used is ............

Cross staff is an instrument used for ............

For the construction of highway (or railway) ............

Sensitiveness of a level tube is designated by ............

The theodolites used for making tacheometric observations by optical wedge system, are ............

If a 30 m chain diverges through a perpendicular distance from its correct alignment, the error in length is ...........…

Pick up the odd instrument ............