Q1)
The method suitable for workings seam under the surface containing valuable property water bodies for whose protection some coal is left unworked is ?
1) Longwall retreat
2) Bord and pillar
3) Hydraulic mining
4) Longwall advancing
Q2)
The width of the headings in bord and pillar method of working depends on?
1) depth of working
2) size of the pillars
3) face machinary used
4) ventilation required
Q3)
With strong roof and unyielding floor tends to?
1) Crush the roof
2) Heave the floor
3) Crush the sides of pillars
4) Spontaneous heating
Q4)
The shape of the pillar that gives maximum percentage of recovery with speed reduced amount of lift for loading is?
1) square
2) rectangle
3) rhombus
4) circular
Q5)
The shape of the pillar in steep seams for haulage and loading and in flat and inclined seam for adoption of high capacity machinery like shuttle cars and locomotive is ?
1) square
2) rectangle
3) rhombus
4) circular
Q6)
For given perimeter the greatest area of support is offered by ?
1) square
2) rectangle
3) rhombus
4) circular
Q7)
In deciding the size of the panel the important factor to be considered is?
1) thickness of the seam
2) output required
3) depth of the seam
4) incubation period
Q8)
The number of panels to be opened at a time is decided by ?
1) Capacity of the direct rope haulage
2) Output desired
3) Thickness of the seam
4) Incubation period
Q9)
In a seam with locomotive haulage system the junctions with main headings are staggered ?
1) For easy travelling of loco
2) to minimize roof exposure
3) to reduce ventilation air loss
4) none of the above
Q10)
Heavy roof fall and even premature collapse may taken place if line of goaf is?
1) parallel to strike
2) diagonal
3) right angle to fault
4) parallel to fault
ANSWERS FOR ABOVE QUESTIONS
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