Question

Given the following staff readings at two levels, determine the Reduced Level (RL) of B. 

Given: - RL of A = 150 m - Find RL of B

• A. 150.35 m
• B. 149.90 m
• C. 151.25 m
• D. 148.50 m

Hint:

In leveling calculations using the HI method, always add the backsight (BS) to the RL of the known point to get HI and then subtract the foresight (FS) to get the RL of the next point.

Answer 1

The Correct Option is A

Step 1: Compute the Height of Instrument (HI)
The HI (Height of Instrument) is calculated as:
\[ HI = RL_A + BS \]
Substituting values:
\[ HI = 150 + 1.80 = 151.80 \text{ m} \]
Step 2: Compute RL of B
\[ RL_B = HI - FS \]
Substituting the foresight (FS) at B = 1.45 m: \[ RL_B = 151.80 - 1.45 = 150.35 \text{ m} \]
Thus, the Reduced Level of B is \( \mathbf{150.35} \) m.