Chain Surveying MCQ with answer and solution

Concept

Perpendicular and oblique offsets

Step-by-step solution

1. A perpendicular offset needs only one measurement (the offset length) after fixing the foot with a cross staff or optical square. 2. An oblique offset or tie needs additional measurements along the chain line.

Explanation

In the perpendicular offset method only the length of the offset has to be measured, so it involves the minimum measurement. Oblique offsets need two measurements from two points on the chain line.

Shortcut

Perpendicular offset = minimum measurement.

Common mistake

Choosing tie offset because it avoids setting out a right angle.