Apr 5, 20202 min
Updated: Apr 8, 2020
21. The main object of running a tie line is to take details of nearby objects
22. Which of the following is an obstacle to chaining but not to ranging ? river
23.A building is an obstacle to both chaining and ranging
24. The main difference between an optical square and a prism square is
that no adjustment is required in a prism square since the angle between
the reflecting surfaces cannot be changed
25.The angle of intersection of the two plane mirrors of an optical square is 45°
26.The allowable length of an offset depends upon the
degree of accuracy required,method of setting out the perpendiculars and nature of ground,scale of plotting
27. Which of the following angles can be set out with the help of French cross staff? either 45° or 90°
28.Which of the following methods of offsets involves less measurement on the ground? method of perpendicular offsets
29.The permissible error in chaining for measurement with chain on rough or hilly
ground is 1 in 250
30.The correction for sag is always subtractive
31.Cross staff is an instrument used for setting out right angles
32.Normal tension is that pull which neutralizes the effect due to pull and
sag
33. Which of the following is not used in measuring perpendicular offsets ?
line ranger
34. If the length of a chain is found to be short on testing, it can be adjusted by
straightening the links
35. The maximum tolerance in a 20 m chain is ±5 mm
36.For accurate work, the steel band should always be used in preference to chain
because the steel band is practically inextensible and is not liable to kinks when in use
37. The length of a chain is measured from outside of one handle to outside of
other handle
38.The true meridian at any place is not variable,The true meridians converge to a
point in northern and southern hemispheres,The maps prepared by national survey departments of any country are based on true meridians.
39. If the true bearing of a line AB is 269° 30', then the azimuth of the line AB is 90° 30'
40. In the prismatic compass the magnetic needle and graduated circle do not move with the box