Permissable errors in surface, under ground, precise and trigonometric levelling respectively.
A. 40 cm/km ; 4 cm/km, 1 mm/km ; 2 cm/km
B. 4 cm/km ; 2 cm/km, 1 mm/km ; 40 cm/km
C. 2 cm/km ; 4 cm/km, 1 mm/km ; 40 cm/km
D. 2 cm/km ; 40 cm/km, 1 mm/km ; 4 cm/km
Answer: Option C
This Question Belongs to Mining Engineering >> Mine Surveying
The stations choosed by main survey lines called . . . . . . . .
A. Temporary stations
B. Main stations
C. Subsidary station
D. None
The 90° corners of a building are set out on the ground by, easily . . . . . . . .
A. Cross staff
B. Mason's square
C. Theodolite
D. Optical square
The arithmetical check for levelling is . . . . . . . .
A. $$\sum {BS} + \sum {FS = {\text{First RL + Last RL}}} $$
B. $$\sum {FS} - \sum {BS} = {\text{Last RL + First RL}}$$
C. $$\sum {BS} - \sum {FS} = {\text{Last RL}} - {\text{ First RL}}$$
D. All
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