Surveying
Cross staff is an instrument used for

measuring bearings of the lines
setting out right angles
None of these
measuring approximate horizontal angles

ANSWER DOWNLOAD EXAMIANS APP

Surveying
For mapping any country

Secondary triangles are further broken into third and fourth order triangles, the points of which are used for detail surveys
Primary triangles are broken down into secondary triangles of somewhat lesser accuracy
Geodetic triangulation of greatest possible sides and accuracy is carried out
All listed here

ANSWER DOWNLOAD EXAMIANS APP

Surveying
The error due to eccentricity of inner and outer axes can be eliminated by

taking both face observations and taking the mean of the two
reading both verniers and taking the mean of the two
double sighting
taking mean of several readings distributed over different portions of the graduated circle

ANSWER DOWNLOAD EXAMIANS APP