The multiplying constant for the tacheometer is, generally, kept as ............

A check line in a chain surveying ............

An example for instrument error in leveling is ............

The apparent error on reversal is ............

Indirect ranging is adopted when the two ends of chain line are ............

The tacheometric method of contouring is particularly suitable ............

An ideal vertical curve to join two gradients, is ............

For a closed traverse the omitted measurements may be calculated ............

The error in measured length due to sag of chain or tape is known as ............