Cross staff is an instrument used for
Answer: setting out right angles
The correction for sag is
Answer: always subtractive
The permissible error in chaining for measurement with chain on rough or hilly ground is
Which of the following methods of offsets involves less measurement on the ground?
Answer: method of perpendicular offsets
Which of the following angles can be set out with the help of French cross staff?
Answer: either 45° or 90°
The allowable length of an offset depends upon the
The angle of intersection of the two plane mirrors of an optical square is
For a well-conditioned triangle, no angle should be less than
A metallic tape is made of
During chaining along a straight line, the . leader of the party has 4 arrows in his hand while the follower has 6. Distance of the follower from the starting point is
For a line AB
Answer: the forebearing of AB and back bearing of AB differ by 180°
In the prismatic compass
Answer: the magnetic needle and graduated circle do not move with the box
If the true bearing of a line AB is 269° 30′, then the azimuth of the line AB is
Select the incorrect statement.
Answer: The true meridians at different places are parallel to each other.
The length of a chain is measured from
Answer: outside of one handle to outside of other handle
For accurate work, the steel band should always be used in preference to chain because the steel band
Answer: is practically inextensible and is not liable to kinks when in use
The maximum tolerance in a 20 m chain is
If the length of a chain is found to be short on testing, it can be adjusted by
Answer: straightening the links
Which of the following is not used in measuring perpendicular offsets ?
Normal tension is that pull which
Answer: neutralizes the effect due to pull and sag