Q101
Open questionSpecific gravity of H2S
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Mining Engineering · all questionsMine Ventilation
Mine Ventilation
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Q102
Open questionFor a person working in an atmosphere containing 21% O2, the exhaled air contains 4.5% CO2 and 16% O2. The respiratory quotient of breathing is
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Q103
Open questionAn air sample taken from the return airway of a district contains the following gases. The Graham's ratio for the district is
| Gas | CO2 | H4 | O2 | N2 | CO |
| Concentration % | 0.4 | 1.17 | 19.92 | 78.49 | 0.02 |
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Q104
Open questionIn an underground working area, CH4 and CO2 are normally expected to be found respectively
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Q105
Open questionThe centrifugal fan types are . . . . . . . .
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Q106
Open questionThe maximum wet bulb temperature in u/g mines is
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Q107
Open questionA mixture of specially prepared manganese dioxide and copper oxide called
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Q108
Open questionA mine worker inhales normal air; whereas, the exhaled air contains 16.65% O2 and 3.83% CO2. The respiratory quotient of breathing for the worker is
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Q109
Open questionThe chemical Hopcalite used in
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Q110
Open questionAir at a density of 1.2 kg/m3 flows in a straight duct such that the velocity at the centre is 12.5m/s. the method factor for the velocity profile is known to be 0.80. The velocity pressure value in the duct in Pa is
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Q111
Open questionIn a mine between upcast shaft and downcast shaft, two airways are connected in parallel and their resistances are 100 and 120 Ns-2m-8 respectively. The resistance of upcast shaft, downcast shaft and the fan drifts are 10, 20, and 5 Ns-2m-8 respectively. The fan drift air pressure is 15 MN/m2. The rate of airflow through the mine in m3
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Q112
Open questionAir at a density of 1.2 kg/m3 flows in a straight duct such that the velocity at the centre is 12.5 m/s. the method factor for the velocity profile is known to be 0.80. The air flow encounters a symmetric expansion such that the cross- sectional are of the duct becomes double. The static pressure value at the inlet and outlet of the expansion are 60 Pa and 90 Pa respectively. Neglecting friction the shock pressure loss on account of expansion in Pa is
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Q113
Open questionGeothermic gradient is
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Q114
Open questionMean air temperature of a 450 m deep downcast shaft is 29°C and that of the upcast shaft is 37°C. The height of the motive column in m is
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Q115
Open questionAir of 20.8% O2, concentration enters a coal mine panel at 20 m3/s and exits with 20.6% O2. The oxygen depletion is due to oxidation of carbon in spontaneous heating process only, assuming the density of oxygen as 1.3 kg/m3 and the calorific value of carbon as 34 MJ/kg, the heat generated in kW from the panel due to spontaneous oxidation is
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Q116
Open questionThe main fan operating point of a ventilation system is shown in the figure below. If an NPV of 200 Pa assists the ventilation system, the resultant pressure (Pa) and quantity (m3) generated by the
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Q117
Open questionThe excess weight of air in D.C air column which gives rise to . . . . . . . .
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Q118
Open questionInterferometers called as
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Q119
Open questionHigh methane liberation is associated with coal having high.
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Q120
Open questionThe smell of nitrous fumes
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