SSC JE Civil Engineering 30-Oct-2020 Shift 2 Paper

Concept:
Height of instrument (HI) = Benchmark (BM) + Backsight
Reduced Level of forwarding station = HI – Foresight Reading
Calculations:Given,
Back sight-reading = 0.865 m
Height of instrument (HI) = 561.365 m
We know that,
Height of instrument (HI) = Benchmark (BM) + Back sight
Reduced Level of station A = HI – Back sight Reading
R.L of A = 561.365 – 0.865
∴ R.L of A = 560.500 m