The walk step of a man is considered equal to:

When the bubble of the level tube of a level, remains central

The vertical distance above or below the datum is called

Planimeter is used for measuring

In a theodolite the line of collimation is

A 'level line' is a

"Cross-section" and "Longitudinal sectioning" is

Pick up the odd instrument

Negative errors are causes in chain, when its length is