UKPSC A.E. Paper III 2013 / UPWRNL AE 2014
⭕ A. Orientation
⭕ B. Parallalism
⭕ C. Levelling
⭕ D. Three Point
📚 Explanation:
The **principle of plane tabling** is based on the concept of **parallelism**.
In plane table surveying, **plotting and field observations are done simultaneously**. For the plotting to represent the ground accurately, the **lines drawn on the sheet must remain parallel to the actual directions on the ground**.
This means that the line joining plotted points on the drawing sheet must be kept **parallel to the line joining the corresponding ground stations**. This condition is known as the **Principle of Parallelism**.
The **principle of plane tabling** is based on the concept of **parallelism**.
In plane table surveying, **plotting and field observations are done simultaneously**. For the plotting to represent the ground accurately, the **lines drawn on the sheet must remain parallel to the actual directions on the ground**.
This means that the line joining plotted points on the drawing sheet must be kept **parallel to the line joining the corresponding ground stations**. This condition is known as the **Principle of Parallelism**.
👉 Therefore, the correct answer is: B. Parallelism
Key Points:
- Parallelism: The plotted lines on the sheet must be parallel to the corresponding ground lines.
- Simultaneous plotting: Unique feature of plane tabling.
- Accuracy depends on perfect orientation & levelling, but the principle is parallelism.
