**1.**If W is the weight of the chain, L is the span and P is the tension or pull, then sag correction for chain line will be

**(W^2L)/(24.P^2).**

**2.**Normal tension is that pull which

**neutralizes the effect due to pull and sag in chain/tape.**

**3.**If O is the angle of slope, L is the length of the slope and H is the difference in elevation between two ends of the line, then slope correction will be

**2.L.sin^2(O/2).**

**4.**Limiting length of offset depends upon the

*accuracy desired, scale of plotting and nature of the ground.*

**5.**Sag correction for chain or tape is always

**negative.**

**6.**Plane tabling is a graphical method of surveying.

7. Chaining or tape is the best method for the linear measurements.

8. Curves are necessary to change the direction and vertical alignments of the routes.