Introduction To Mining Engineering - Study Mode
[#391] When does the first caving in long wall working starts?
Correct Answer
(A) it usually starts when the tensile stress in a certain point of the roof over the gob exceeds its tensile strength
[#392] A longwall face cut by double back shuffle method can be only worked with
Correct Answer
(C) double ended ranging drum shearer
[#393] What is the relationship between break-even stripping ratio (BESR) and ordinary stripping ratio (OSR)?
Correct Answer
(C) BESR > OSR
[#394] Which of the following unique mining method is known as novel method?
Correct Answer
(B) methane drainage
[#395] Which of the following factor is considered for calculation of cycle time of excavating machine such as shovel, drag line etc?
Correct Answer
(C) swing factor