Q1)
Working coal in the pillars formed in the operation in bord and pillar mining is ?
1) Working in the broken
2) Working in the whole
3) Longwall retreat
4) Slicing
Q2)
The galleries driven through the pillar for forming stooks are called?
1) stooks
2) splits
3) slices
40 judd
Q3)
The pillars formed during development are split into small pillars are called?
1) stooks
2) splits
3) slices
4) judd
Q4)
The pillar is splitted into 2 or more stooks if the pillar size is more than?
1) 15 X 15 sq.m
2) 18 X 18 sq.m
3) 20 X 20 sq.m
4) 25 X 25 sq.m
Q5)
Once the pillar extraction is commenced the splitting is of pillars may be done upto.....pillars ahead of the pillar
is under extraction?
1) 1
2) 2
3) 3
4) 4
Q6)
During development the height of the gallery should not exceed?
1) 2m
2) 3m
3) 4m
4) 5m
Q7)
During extraction of coal the minimum thickness of the coal(rib) is left against the goaf is?
1) 1 m
2) 2 m
3) 3 m
4) 4 m
Q8)
With a good sandstone roof the area exposed may not more than .....sq.m at one stook extraction and ......sq.m if 3-4 stooks under extraciton?
1) 20 ; 400
2) 30 ; 600
3) 40 ; 900
4) 50 ; 900
Q9)
The fall which takes place soon after whithdrawal of supports is called ?
1) Local fall
2) Main fall
3) Air blast
4) Rock burst
Q10)
During depillaring if the roof is laminated local fall occurs ....hours after the props are withdrawn?
1) 1-3
2) 3-6
3) 4-10
4) 10-14
ANSWERS FOR ABOVE QUESTIONS
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