A. the instrument is to be shifted frequently
B. fly levelling is being done over long distance
C. many readings are to be taken from a single setting of the instrument
D. all of the above
A. radius of level tube
B. length of level tube
C. length of bubble of level tube
D. none of the above
A. equidistant from A and B
B. closer to the higher station
C. closer to the lower station
D. as far as possible from the line AB
A. contour line
B. horizontal equivalent
C. contour interval
D. contour gradient
A. A contour is not necessarily a closed curve
B. A contour represents a ridge line if the concave side of lower value con¬tour lies towards the higher value contour
C. Two contours of different elevations do not cross each other except in case of an overhanging cliff
D. All of the above statements are correct
A. ranging
B. centring
C. horizontal control
D. vertical control
A. direct method
B. square method
C. cross-sections method
D. tacheometric method
A. a quick method
B. adopted for large surveys only
C. most accurate method
D. suitable for hilly terrains
A. depression
B. hillock
C. plain surface
D. none of the above