Mining Engineering Interview Questions and Answers
1. Which cut is used for solid blasting in Indian coal Mines
Wedge cut
2. Permitted explosives are safe to use because
Special chemical are used to extinguish the spark produced during blasting.
3. Burden is the distance between
Distance between first row of blast holes and bench
4. Which of the following explosive have maximum strength
RDX
5. To measure the performance of blasting which factor is calculated
Powder factor
6. What is the formula for blast ability?
B = c / t
Where B = Blast ability c = compressive strength t = tensile strength of a rock
7. As per provision of regulation 170 (1a)(of CMR 1957 danger zone is an area falling a radius of ——–
300m
8. While blasting in hot strata the temperature of hole should not exceed
80 c
9. Fly rocks during opencast blasting is controlled by
muffled blasting
10. While dealing with Misfire shot the relieving hole is drilled at a distance not less than
10 m
11. As per CMR the recapping of rope is done once at least in every
6 months
12. what is the maximum angle of fleet is permissible in winding as per CMR
1.5
13. a coal seam is said to be of degree III if rate of emission of gas in m3 /te of coal raised is
more than 10
14. reportable injury means any injury other than serious bodily injury, which involves the enforced absence of injured person from work for a period of
72 hours or more
15. When the air and mineral flow is in same direction the ventilation is known as
Homotropal ventilation
16. Roof falls are more common if the face is at
Parallel to the main cleat
17. A seam is worked at a depth of 70 mtrs . from surface and the width of the galleries is 3.2 mtr the dimension of the pillar should not exceed
16.5 mtrs
18. in board and pillar panel worked in conjuction with hydraulic stowing extraction line preferred is
step diagonal
19. emulsion explosive is mixtur
ammonium nitrate, water, hollow microballons
20. Coalfication has taken place in order of
peat . lignite, bituminous, anthracite
21. coal seams are normally found in
Sedimentary rocks
22. In India a coal seam is defined as a thick coal seam if its thickness is
More than 4.8m
23. black damp is a mixture of
CO2 + N2
24. When working approaches waterlogged areas apparatus used as precautionary measure is
Burn side boring
25. keps are used in
Drum winding
26. Chasnala mine disaster is due to
Explosion
27. permissible dust concentration in Indian mines is
5mg/m2 of air
28. Factor of safety for winding rope is
10
29. Life of winding rope is
4.5 years
30. Runaway switch is used in
Rope haulage
31. The purpose of wire gauge in flame safety lamp is
to prevent the passage of flame from inside to the outside of the lamp
32. the hopkalite used in CO detector is a mixture of MnO2 and
Silica gel
33. Self-rescuer can be used upto ________ % of CO
3
34. According to CMR 1957 CH4 % in return airway should not exceed
0.75%
35. the wet bulb temperature in development faces should not exceed
33 C
36. In contiguous seams means the parting between two seams is within
9m
37. which of the following instruments is used to measure the cooling power of the air
Katathermometer
38. Joining of two ropes is called as
Splicing
39. Clifton pulley is used in
Endless rope haulage
40. when shot hole is blasted at a uarry face, fracture of rock takes place by
Both by compression and tensile
41. The minimum accuracy of colliery triangulation survey is aimed at
1 in 5000
42. fast and accurate extension of centerlines in long tunnels can be done by
Laser beam ranger
43. Mechanized opencast mining in India is economically feasible at present if the overburden to coal ratio is approximately up to
1in 8
44. for overburden removal with shovel dumper combination the optimum size of the dumper depends on
Size of the shovel and the distance of haul
45. In an underground coal mine the place where explosive is stored in underground is called as
Reserve station
46. for heavy duty crushing on hard material the type of jaw crusher normally selected is
Blake type double toggle
47. To separate two finely divided solids from one another the process to be selected is
Floating
48. A Zn deposit is formed by a geological process is called
Hydrothermal
49. cut and fill stoping can be operated
Both underhand and overhand
50. If the RD of the ore and wall rock are low the method of stoping selected will be
Block caving
51. the stoping method in which maximum cost is incurred is
Suare set stoping
52. In the panel caving system of block caving the contact between the ore and capping is kept
Inclined
53. The ventilation plan of a mine should be on a reference scale o
2000:1
54. In any working below ground there should be provided at least two shafts or incline which should be away from each other by a minimum distance
13.5 mtrs
55. Poisson ratio is a relationship between
Longitudinal strain and lateral strain
56. RD is a uantitative index based on core recovery procedure, which is determined by incorporation of only those pieces of core that is
Greater than or eual to 100mm
57. In a contoured Map if there are higher values in side the loop it indicates
Ridge
58. The intersection of a vertical line through the observer’s station with the upper portion of the celestrial sphere is called
Nadir
59. the effect of curvature in leveling is an error, which is
Subtractive
60. The minimum accuracy of colliery triangulation survey is aimed at
1in 5000
61. The earliest indication of the spontaneous heating of coal can be given by
Sweating of strata
62. In an underground coal mine ventilated by 100 HP fan (Air HP) it is reuired to double the uantity ofair for the purpose of air HP reuired will be
800 H.P.
63. Ore for metal lead is
Galena
64. DGMS comes under
Labour Ministry
65. lily controller is used for the protection in winder
Over wind
66. balance rope is used on Koepe friction winder
To balance cage winding rope and to reduce power consumption
67. Factor of safety (FOS) in connection with winding
applicable to static loading
68. LHD is a
Loading, hauling and dumping machine
69. the shape of the casting in a centrifugal pump is
involute
70. Magnetic separation is
A dry method
71. Notice to regional inspector of mines about occurrence of serious accident is given in form
IV A
72. Blasting Gallery method is not suitable for working seam thickness
Less than 7 m
73. The size and speed of rotation being the same the head developed is max in case of
A forward bladed centrifugal fan
74. In water gas explosion the two highly explosive gases that are involved are
H2 and CO
75. In an underground working area CH4 and CO2 are normally expected to be found respectively
Near the roof and near the floor
76. The most important parameter of a dust that governs its physiological effect is
Size of dust
77. In a mine a big roof fall has taken place in the mine intake place in main intake airway. The fan drift water gauge
Will register an increase
78. Stone dust barriers are installed in underground
to prevent the imitation of coal dust explosion
79. 60 dB + 60dB
63 dB
80. In ventilation network analysis, kirchhoff’s first law is used which states
the algebraic sum of uantitities flowing at a junction is zero
81. Atkinson’s euation P = R2 is applicable for
Laminar flow only
82. NVP in a mine is more in
Winter as the air going in is cold
83. Reynolds number varies
Directly with flow velocity
84. Resistance of a mine airway does not depend upon
uantity of air flowing in it
85. An electric cap lamp as used in mine has a fuse of capacity
4 amp
86. A 10% increase in cross sectional area of a roadway will reduce the resistance approximately by
10%
87. The recommended instrument for the air borne respirable dust sampling in the Indian mines is
NCB/MRE-113A
88. The oxygen concentration in underground mine should not be less than
19%
89. the thickness of ventilation stopping should not be less than
38 cms
90. A cap lamp must be able to produce an illumination of
0.25 lumans
91. Gravimetric dust samplers works on the principals of
filtration
92. carbon monoxide detector tubes uses
Potassium palladium sulphate
93. Installation of booster fan in one district
Reduces the flow of air in other district
94. Pitot tube is generally used for
Measurement of air velocity in ducts
95. Gas chromatography utilizes the principal of
Solid gas absorption
96. Explosibility of coal dust generally does not depends on
d)Colour of dust
97. For measuring relative humidity we use
Psychrometer
98. Geothermal gradient in Indian coalfields is about
1 0 C / 38m
99. A drum Shearer is mounted on
Its own skid
100. Dust generation may be reduced by drilling
Sharp bit