Explanation:

When using a leveling staff that is inclined at a staff station, the reduced level calculated from observation will be less than the true R.L. This is because the inclination of the staff affects the reading taken by the surveyor.

Reasoning:

When a leveling staff is inclined at a staff station, it means that the staff is not held vertically but at an angle. This can happen due to various reasons such as uneven ground, obstacles, or other surveying conditions.

Effect on Reading:

The inclination of the staff affects the reading taken by the surveyor. When the staff is inclined, the distance between the staff and the surveyor's eye is different from the actual height of the staff. This causes an error in the readings and leads to an incorrect calculation of the reduced level.

Calculation of Reduced Level:

The reduced level is calculated based on the readings taken with the leveling instrument. The instrument measures the vertical distance between the instrument and the staff, and this distance is used to calculate the reduced level.

Inclined Staff:

When the staff is inclined, the distance between the instrument and the staff is not the actual height of the staff. This means that the calculations based on this distance will be incorrect, leading to a reduced level that is less than the true R.L.

Comparison with True R.L:

The true reduced level can be determined by correcting the error caused by the inclined staff. This can be done by using trigonometric calculations or by using a correction factor based on the angle of inclination. Once the correction is applied, the true reduced level can be obtained.

Conclusion:

In conclusion, when a leveling staff is held inclined at a staff station, the reduced level calculated from observation will be less than the true R.L. This is because the inclination of the staff affects the readings taken by the surveyor. It is important to apply the necessary corrections to obtain the accurate reduced level.