In the prismatic compass
Local attraction in compass surveying may exist due to
Local attraction is a term used to denote any influence, which prevents the needle from pointing to the magnetic north in a given locality. Difference of fore bearing and back bearing = 0 ⇒ No local attraction.
The horizontal angle between the true meridian and magnetic meridian at a place is called
A negative declination shows that the magnetic meridian is to the
If the lower clamp screw is tightened and upper clamp screw is loosened, the theodolite may be rotated
The error due to eccentricity of inner and outer axes can be eliminated by
Error due to eccentricity of inner and outer axes means that the centre of graduated horizontal circle does not coincide with the centre of vernier plate.
While measuring horizontal angles by the method of repetition with a theodolite, readings are taken on both the verniers. Which one of the following errors will be eliminated by reading both the verniers?
if the quadrantal bearing of a line is N25°W, then the whole circle bearing of the line is
The following bearings were observed while traversing with a compass:
Which stations were affected by local attraction?
As the difference between F.B and B.B of line AB is exactly 180°, stations A and B are free from local attraction which is not the case with line CD.
Hence stations C and D are affected by local attraction.
The coordinates of two end-points A and B of a traverse line AB are
The bearing of the line AB will be
Correct Answer :- c
Explanation : Bearing of line AB=tan-1 (Xb-Xa/Yb-ya).
= tan-1(infinity Or not define).
Now by use of trigonometric table find the angle which tan value should be infinity or not define
So the value is 90°.