For preparation of contour plan for a route survey ............

The angle between two plane mirrors of optical square is ............

The line of sight is kept as high above ground surface as possible to minimize the error in the observed angles due to .…

The amount of correction due to local attraction at a place ............

Let the angular value of one graduation of a tube of length x be \theta seconds and R be the radius of its internal curv…

In leveling, the correction for combined curvature and refraction (in metres) is equal to ............

The following sights are taken on the turning point ............

A staff reading taken on a point whose elevation is to be determined as on a change point is called ............

Handles of chains are made up of ............