It's a coal mining extraction method where simultaneous development and extraction is done and parallel faces are separated by a series of fender block of coal. The mining is known as
A. widestall method
B. wongawilli
C. room and pillar
D. bord and pillar
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'Loop-take-up' arrangement is associated with
A. scraper chain conveyor
B. shaker conveyor
C. belt conveyor
D. cable belt conveyor
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The maximum voltage for handheld portable apparatus used in underground mines is
A. 30 V
B. 125 V
C. 220 V
D. 330 V
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Which of the following actually determines the periodic weighting length in long wall working?
A. thickness of immediate roof
B. physical properties of main roof
C. the stratigraphic sequence
D. compressive strength of immediate roof
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Side Discharge Loader (SDL) is a
A. crawler mounted machine
B. tyre mounted machine
C. both A and B
D. rail mounted machine
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Why fleet angle is limited to 1.5°?
A. to reduce the side travel on the pulley
B. to prevent excessive wear & tear of the winding rope
C. it allows maximum persons to travel at a time in a cage
D. it allows use of rope having lesser diameter
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The suitable method of mining a 2 m thick strong sulphide ore deposit within strong wall rocks dipping at 18° and occurring at 60 m below the surface is
A. overhand stoping
B. top slicing
C. underhand longwall stoping
D. breast stoping
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Which of the following is mainly considered for deciding size of panel in depillaring operation
A. volatile content of seam
B. geological considerations
C. support system approved
D. incubation period
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In any underground mining methods cut, drill and blast combined known as
A. face dressing operation
B. coal preparation operation
C. rock mining operation
D. blast mining operation
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Which types of detonators are recommended to use with Permitted explosives during blasting off the solid?
A. ordinary detonators
B. non-incendive alumina detonators
C. non-incendive copper short delay detonators
D. non-incendive iron capped delay detonators
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P-5 explosives are used for
A. pre-cut blasting
B. solid blasting
C. open cast blasting
D. over burden blasting
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Order the followings in decreasing stability of host rock:
A. 1, 2, 3, 4
B. 2, 3, 4, 1
C. 4, 3, 2, 1
D. 4, 2, 3, 1
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Which of the following controls the magnitude and direction of the front abutment pressure for immediate roof in long wall working?
A. Young's Modulus
B. stratigraphic sequence
C. periodic caving
D. strong main roof
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In a 3rd degree gassy mine the velocity of air measured at 7.5 m out bye of the discharge end of an air pipe should be
A. 25 m/min
B. 45 m/min
C. 60 m/min
D. 75 m/min
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In depillaring operation major coal losses are from
A. coal left in underground for unfavourable geological conditions
B. coal left to protect surface features
C. coal loss due to spon heating
D. coal left as ribs within the pillars
Select an option to see the answer and solution.
Continuous miner and shuttle car combination is NOT applicable in mining with
A. rib pillar extraction technique
B. wangawilli system
C. room and pillar method
D. longwall method
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The angle of draw in a trough subsidence helps in determining the
A. Maximum subsidence
B. Extent of surface subsidence
C. Plane of fracture
D. Critical width of the opening
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Which gas is synonymous with 'White damp'?
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Panel barrier is punctured for
A. district transport layout
B. district return
C. pumping water out of the panel
D. to take out miners
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Every man-hole shall be kept clean & clear of obstruction, white-washed for a distance of not less than
A. 0.3 m
B. 0.6 m
C. 0.9 m
D. 1.2 m
Select an option to see the answer and solution.
