For which of the following permanent adjustments of theodolite, the spire test is used?

Levelling across a river is done by

Chain surveying is well adopted for

An imaginary line joining the points of equal elevation on the surface of the earth represents

The total length of the curve is equal to

One mile equals to

Right face and left reading are taken to

Number of subdivision per meter length of a levelling staff is

The most reliable method of plotting a theodolite traverse is