MINING ENGINEERING GATE PREVIOUS QUESTIONS - 4

1. out of support categories given for an underground coal mine, identify the active support

1. wire mesh
2. shotcrete
3. fully grounted roof bolt
4. hydraulic prop

2. messive sandstone in immediate roof delays the local fall in goaf of a coql mine. under this condition, crushing of the pillas at outbye side is called

1. coal bump
2. overriding of pillars
3. stiffening of pillars
4. spalling of pillars

3. the angle in degrees at which a ridge line intersect contours is

1. 0
2. 30
3. 45
4. 90

4. in a drum hoisting system through a vertical shaft, overwinding is prevented by

1. Lily controller
2. detaching hook
3. caliper brake
4. safety catch

5. the excess pore pressure in backfill material in a cut-and-fill stope leads to

1. reduction in the strength of the wall rock
2. enhancement of bearing strength of fill
3. loss of shear resistance of fill
4. prevention of progressive failure of crown pillar

6. the primary purpose of cut holes for blasting in underground drivage is to

1. additional additional fee face
2. have smooth surface after blasting
3. prevent over breakage
4. reduce noise

7. Dilatancy of rock is associated with

1. increase in surface area after fragmentation
2. decrease in volume due to compression of rock
3. increase in shear strain due to cracking of rock
4. increase in volume due to cracking of rock

8. low shock and high gas pressure explosive is generally used for the blasting of

1. hard and brittle Rock mass
2. soft and joint rock mass
3. hard and massive intact Rock mass
4. soft and massive intact rock mass

9. in a fully mechanised bord and pillar mining system winning of coal and its transportation from the face is commonly carried out with the combination of

1. continuous miner, shuttle car, feeder breaker and belt conveyor
2. continuous miner, LHD, feeder breaker and chain conveyor
3. continuous miner, SDL, feeder breaker and belt conveyor
4. continuous miner, shuttle car, feeder breaker and chain conveyor

10. in self-contained chemical oxygen self rescuer, oxygen is produced by

1. hopcalite
2. potassium peroxide
3. sodium hydroxide
4. protosorb