# Chain Surveying Viva Questions

Chain Survey Viva Questions

1. Which line is baseline in the layout of survey?

The longest main survey line is the baseline in the layout of the chain survey

2. What is the length of long offsets in Chain surveying?

More than 15 meters

3. If a 20 m tape held 40mm out of the line, what is the resulting error per tape length?

4mm

4. What is a check line?

The Check line can be defined as the line joining the apex of a triangle to some fixed point on the opposite side.

5. What you know about Tie line?

The line joining some fixed points on the main survey line is known as Tie line. The Tie line in a chain survey enables the surveyor for locating the interior details far away from the main chain lines.

6. In Chain survey, which line fix up the directions of all other lines?

The baseline

7. What are the uses of a Plumb bob?

Main use of a plumb bob is the measuring distances along slopes in a hilly country. It is also used for testing the verticality of ranging poles and also used for activate centering of a theodolite over a station mark.

8. In which situations chain surveying is most suited?

Chain surveying is mostly used when the surveying area is small, the plans are required on a large scale and the ground is fairly level and open with simple details.

9. What is the minimum angle level in a well conditioned Triangle?

30 degrees

10. Which line checks the accuracy of the framework in a chain survey?

The check line

11. What is the limiting length open the upset when it's perpendicular direction is set out by an eye?

15 m

12. For locating a point by oblique offset, what is the  minimum number of  distances to be measured?

At least two distances

13. What are the factors on which the accuracy in laying down and measuring of the perpendicular offsets depends?

Scale of plotting, Length of offset and importance of the object.

14. What is the use of oblique offsets?

For accurately fixing the position of a point, it must be located by oblique offsets.

15. Which factor limit the field work in Chain surveying?

Linear measurements

16. Whether the general layout of the chain lines depend the accuracy of measurement in the chain surveying?

No

17.   Weather the limiting length often Oxford depends on the indefinite features to be surveyed?

No

18. How the baseline is measured?

By chain

19. The distance measured along a chain line is called?

Chainage

20. What are the factors depending the limiting length of an offset?

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

21. What is is the angle bye French cross staff?

45 or 90 degrees.

22. What is used for setting out of long offsets?

Open cross staff

23. In an optical square, what is the angle of intersection of horizon mirror and index mirror?

45 degrees

24. Compare optical square and Prism square?

The working principle of both the optical square and prism square are same. In a prism square, since the angle between the reflecting mirrors is fixed no adjustment  is required.

25. Which land feature is an obstacle to chaining and not in ranging?

Rivers

26.  Which land feature is an obstacle to ranging and not in chaining?

Hills and Buildings

27. What is is the first step taken in chain survey execution?

Reconnaissance

28. What is the basic principle of  optical square?

Double reflection

29. A field is measured with a 1.0 percent too long chain is 10,000 acres. What is the the correct area of the field?

10,201 acres

30. What instrument is used for the measurement of angles?

Sextant

31. Which instrument is used for setting out an offset at right angle?

Open cross staff

32. In which angle, the adjustable cross staff is used for setting out an offset?

At any angle

33. Half silvered and half un silvered glass in an optical square is?

The index glass

34. Which glass in an optical square is wholly silvered ?

The index glass

35. What are the instruments belongs to a class of reflecting instruments?

Line Ranger, box sextant and prismatic compass

36. What is the angle between the first incident ray and the last reflected ray in an optical square?

90°

37. What is the angle between the reflecting surfaces of a prism square?

45 degrees

38. Is it possible to set offset correctly on both sides, if the chain line run a noun north south direction is horizontal and the ground in east West direction is slopping?

Yes

39. What is an equilateral triangle?

It is the best shape Triangle to be used in triangulation so that the distortion due to errors in measurement and potting is minimum.

40. What you know about Tie stations?

The main survey lines have subsidiary stations known as tie stations. Tie lines are lines which joins the tie stations. In the chain survey map these lines are mainly taken to fix the directions. In Chain surveying these lines are also taken to form chain angles where triangulation is impossible.