Question

Plumb bob lines at two different places in plane surveying are

• A. Inclined
• B. Perpendicular too each other
• C. Parallel to each other
• D. Cut at the center of the earth

Answer 1

The correct option is C Parallel to each other

Since in plane surveying, it's assumed that the earth's surface is flat and does not take into account the spheroidal shape of the earth so the level line is considered straight and all plumb lines are considered parallel.

A level line is a line lying on a level surface whose each point is perpendicular to the direction of gravity whereas a plumb bob line runs along the direction of gravity and therefore, perpendicular to the plumb line at all points.