Removal of parallax, may be achieved by focusing

Line of collimation

The angle by which the forward tangent deflects from the back tangent of a curve is called

The combined correction due to refraction and earth's curvature is

When a chain encounters a river

If the whole circle bearing of a line is 180°, its reduced bearing is

At magnetic poles, the dip of magnetic needle is

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

A chain may get elongated due to