If the barometric pressure at a place is 'h' mm of mercury, convert into SI units.
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Mining Engineering · all questionsMine Ventilation
Mine Ventilation
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Four psychrometric processes P, Q, R and S are shown in the psychrometric chart below. These processes respectively represent
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Effective temperature is estimated from
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Bypass valve in a compressed oxygen type self-contained breathing apparatus is meant to
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In the Coward flammability diagram, the respective percentages of methane and oxygen at the nose limit are
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The total pressure and the static pressure measured at a point in a ventilation duct are 20 mm and 10 mm of water gauge respectively. If density of air is 1.2 kg/m3, the velocity of the air in m/s is
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20 m3/s of air flow through a long wall panel having 1000 tpd of production. Between the intake and return of the panel, the firedamp increases from 0 to 0.2%. The rate of firedamp emission is
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A fan running at 200 rpm develops a pressure of 50 mm water gauge; the fan speed is increased to 300 rpm. the water gauge developed will be
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If the deficiency ratio in a mine is 2%, it indicates
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A main fan of a mine circulates 40 m3/s of air at a pressure of 500 Pa. the mine has two splits of equal resistance. The trunk airways have a total resistance of 0.2 Ns2/m8. When a booster fan is installed in one split, the flow of air in the other splits stops. Assuming that the pressure remains unchanged, the new air quantity flowing through the mine in m3/s is
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Which one of the following is used as a reviving apparatus in u/g coal mine?
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When CO reacts with haemoglobin it changes in to . . . . . . . .
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A mine ventilation system consists of two splits A and B with resistances of 0.8 Ns2m-8 and 3.2 Ns2m-8, respectively as shown in figure. Trunk airways have resistance of 0.2 Ns2m-8. The main mine fan is generating pressure of 500 Pa.
The air quantities in m3/s circulated in the splits A and B respectively are
The air quantities in m3/s circulated in the splits A and B respectively are
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A sealed area known to have black damp has 18% O2, 2% CO2, and 78% N2. If fresh air has 21% O2, 0.03% CO2 and 78.97% N2, the percentage of black damp in the are is
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Explosibility of H2 by volume is . . . . . . . .
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Which one of the following composition of methane in air is most explosive in nature?
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The wet kata for light manual workers is
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Air samples collected from the intake and the return gates of a retreating longwall face show methane concentration values of 0.1% and 0.8% respectively. The production from the longwall face is 2000 tonne/day and the air quantity circulating the face is 15 m3/s. The rate of methane emission in m3 per tonne of coal produced is
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In order to estimate the NVP in a mine, measurements are made at the main fan as shown below.
The NVP in Pa is
| Fan speed (RPM) | Fan drift pressure (Pa) | Fan quantity (m3/s) |
| 800 | 655 | 82.2 |
| 950 | 730 | 85.5 |
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Q100
Open questionMatch the following in the context of underground mine environment
| Instrument | Measuring parameter |
| P. Haldane apparatus | I. Humidity |
| Q. Godbert-Greenwald apparatus | II. Air velocity |
| R. Hygrometer | III. Mine air composition |
| S. Anemometer | IV. Ignition point temperature |
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