Mine Environmental Engineering - I Mid - I, September - 2014

1.The most important parameter of a dust that governs its physiological effect is
  • Concentration of dust in air
  • Shape of dust
  • Time of exposure
  • Size of dust
Answer: D
2.Temperature rise per 100m depth due to auto compression in a dry shaft is
  • 0.5*c
  • 1.0*c
  • 0.75*c
  • 1.25*c
Answer: B
3.The mixture of extinctive gases carbon dioxide and excess nitrogen is
  • Fire damp
  • Black damp
  • White damp
  • Stink damp
Answer: B
4.the composition of oxygen in atmosphere is
  • 20.93
  • 21
  • 19.7
  • 18.3
Answer: A
5.In cross measure bore hole method of methane drainage ,the spacing between the holes is usually
  • 5-10m
  • 10-15m
  • 15-20m
  • 20-30m
Answer: D
6.The layering no.needed to prevent pronounced methane layering is
  • Lower for a roadway with a smooth surface
  • Lower for a roadway with a sleep inclined
  • Higher for ascensionally ventilated roadway
  • None of the above
Answer: C
7.A 10% increase in cross-sectional area of a roadway will reduce the resistance approximately by
  • 10%
  • 20%
  • 30%
  • 40%
Answer: A
8.Apsychrometer is used for measuring at a place its
  • Relative humidity
  • Temperature
  • Methane content
  • Noise level
Answer: A
9.The oxygen concentration in u/g working should not be less than
  • 20.93%
  • 20%
  • 19%
  • 18%
Answer: C
10.The thickness of ventilation stoppings should not be less than
  • 27cm
  • 38cm
  • 35cm
  • 47cm
Answer: B
11.methane content is more in coals that are ----------------
Answer: deeper
12.NVP in a mine is more in----------------------------------------
Answer: winter as the air going in is cold
13.resistance of a mine airways does not depend upon-------------------
Answer: quantity of air flowing in it
14.the positional efficiency of a surface air-conditioning plant in an u/g mine------------------with time
Answer: does not vary with time
15.phon is unit of------------
Answer: loudness
16.maximum quantity of air leaves in a coal mine .ventilation system at the --------------------
Answer: surface air lock
17.for measuring relative humidity we use --------------
Answer: psychrometer
18.carbon monoxide detector tubes uses-------------------
Answer: potassium palladium sulphate
19.To reduce the flow of air in other district---------------fan should be installed.
Answer: booster
20.konimeter measures the dust concentration in terms of--------------
Answer: PPcc