Maximum supports are required within 10 m of freshly-exposed roof-why?
A. concentration of maximum person are there in the face
B. that portion generally remain unsupported due to violence of blasting & incumbent strata pressure is shifted towards pillar edge
C. this is the only place of working in the district in a mine
D. it is easy to install supports at the face
Answer: Option B
This Question Belongs to Mining Engineering >> Introduction To Mining Engineering
A. Normal distribution
B. Skewed distribution
C. Lognormal distribution
D. Poisson distribution
A. 3 level heading district
B. 4 level heading district
C. 5 level heading district
D. 6 level heading district
It is very difficult to control shaley roof if coal is not left with the shale why?
A. It is weak in nature
B. It has weathering effect
C. It has great affinity to absorb moisture and get departed from immediate roof
D. It reacts with coaly surface
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