List of top Mining Methods and Machinery Questions on Fluid Mechanics asked in GATE MN

In a longwall panel, air flows at a velocity of 1.2 m/s through a 900 m long gate road of 2.5 m height and 3 m width. The coefficient of friction is 0.022 Ns$^2$m$^{-4}$. The frictional pressure drop, in Pa, between two ends of the gate road is _______ (rounded off to 3 decimal places).
A mine void of dimension 100.0 m x 2.0 m x 1.2 m is to be filled in 3 hours by hydraulic stowing. The sand to slurry ratio is 0.4. If the hydraulic fill factor is 0.9, the hourly consumption of water for the operation, in m\(^3\), is ________ (rounded off to 2 decimal places).
Hydraulic fracturing method is used to determine the major principal stress (\( \sigma_1 \)) in an underground rock strata having tensile strength of 6 MPa. The minor principal stress (\( \sigma_3 \)) in the strata is 8 MPa. If fluid pressure of 10 MPa is required to fracture the vertical borehole in that strata, the magnitude of \( \sigma_1 \), in MPa, is:
Hydraulic fracturing method is used to determine the major principal stress (\( \sigma_1 \)) in an underground rock strata having tensile strength of 6 MPa. The minor principal stress (\( \sigma_3 \)) in the strata is 8 MPa. If fluid pressure of 10 MPa is required to fracture the vertical borehole in that strata, the magnitude of \( \sigma_1 \), in MPa, is:
In a longwall panel, air flows at a velocity of 1.2 m/s through a 900 m long gate road of 2.5 m height and 3 m width. The coefficient of friction is 0.022 Ns$^2$m$^{-4}$. The frictional pressure drop, in Pa, between two ends of the gate road is _______ (rounded off to 3 decimal places).
A mine void of dimension 100.0 m x 2.0 m x 1.2 m is to be filled in 3 hours by hydraulic stowing. The sand to slurry ratio is 0.4. If the hydraulic fill factor is 0.9, the hourly consumption of water for the operation, in m\(^3\), is ________ (rounded off to 2 decimal places).
An intake shaft has resistance of 0.05 Ns$^2$/m$^8$ up to depth 400 m. Airflow rate = 100 m$^3$/s, air density = 1.2 kg/m$^3$. Barometer reads 99.375 kPa at surface. Find the barometer reading at 400 m depth (kPa), rounded to two decimals.
A pump lifts mine water (density 1020 kg/m$^3$) at 250 m$^3$/hr from 150 m depth. Head loss = 15 m, efficiency = 68%. Find motor input power (in kW), rounded to two decimals.
The cost of a screw compressor with an estimated life of 15 years is ₹21,00,000. If the depreciation charged using the ‘sum-of-the-years-digits’ (SOYD) method at the end of the 4th year is ₹2,00,000, the salvage value (rounded off to one decimal place) is __________.