Question

A surveyor assumes P as difference in elevation between Points X and Y having slope S. What will be the expression to calculate slope correction?

1. P2/2S
2. P2/4S
3. S2/2S
4. P2/2S2

Answer 1

Correct Answer - Option 1 : P2/2S

Explanation:

Correction for slope: 

In a chain survey distance measured between two-point should always be a horizontal plane. But sometimes due to slope on-ground measurement taken on the sloping ground, slope correction is required.

Note:

The distance measured along the slope between two stations is always greater than the horizontal distance is known as slope correction.

This correction is always negative.

Slope correction = P2/2S

Similarly, Correction for slope if angle θ is given  

Slope correction = L(1 − Cosθ)