Home/Volume-1/Longwall and Other Methods of Working Volume-1 Longwall and Other Methods of Working Admin02/08/20240 197 Less than a minute Report a question What's wrong with this question? You cannot submit an empty report. Please add some details. 0% Longwall and Other Methods of Working Longwall and Other Methods of Working 1 / 20 1. The longwall retreating method of UK is called as? Breton system Anderton system Butten system Blaning system 2 / 20 2. The longwall advancing in UK is called as? British system Breton system Butten system Blaning system 3 / 20 3. The C.M. cut coal, load and transfers it on a built in chain conveyor on to a car at the end of each cut and the car? takes away the coal transports to a belt conveyor transports to a trunk belt none of the above 4 / 20 4. The roof fall takes place during caving in the span of ? 6 to 8 hrs 6 to 24 hrs 24 to 36 hrs 48 to 60 hrs 5 / 20 5. When the size of the goaf formed exceeds the span of ....times the thickness of the seam the roof tends to break into pieces? 8 to 10 10 to 12 12 to 15 15 to 18 6 / 20 6. In unit face the face is extracted in one go without any interruption with the face length varies from? 50 to 80m 50 to 100m 50 to 120m 50 to 150m 7 / 20 7. The power supports widely used in longwall mining in India are? chocks friction props hydraulic supports hydraulic props 8 / 20 8. In longwall advancing the gate roads extend slightly beyond the face and the extended portion of the gate is called? Buttock Tail gate Stable Canch 9 / 20 9. In longwall retreating the size of the panel normally does not exceed in area? 30 ha 50 ha 100 ha 150 ha 10 / 20 10. The line of extraction in bord and pillar method of depillaring if the seam is gassy thick with strong roof and liable to spontaneous heating? Diagonal line Step diagonal Parallel to the line of strike Arrow head 11 / 20 11. The types of coal extraction in longwall face are? Unit and semi unit Unit and half unit Full unit and semi unit Full unit and half unit 12 / 20 12. In advanced countries continuous miner is the combination of? drill and loader drill, loader and prop setter drill, loader and coal cutter drill and coal cutter 13 / 20 13. The length of the longwall face depends on? Machinery used Gradient Geological disturbances All of the above 14 / 20 14. The overall productivity from longwall workings is generally ....times higher compared to bord and pillar working? 3 to 4 4 to 5 1 to 2 2 to 3 15 / 20 15. The limiting gradient for longwall method is? 0 to 20 deg 10 to 30 deg 20 to 40 deg 30 to 40 deg 16 / 20 16. In longwall advancing the line of extraction is always parallel to? face line line of strike line of dip line of cross cut 17 / 20 17. In longwall method of working the percentage of extraction in depillaring and extraction stage is about ? 20 to 40 40 to 50 50 to 60 80 to 100 18 / 20 18. In semi unit face the face is divided into 2 units of ....lengths each? 50m 60m 75m 100m 19 / 20 19. Which method of longwall is adopted in India? advancing retreating sublevel top slicing 20 / 20 20. With regular fracturing roof the normal range of periodicity of main falls is ? 20 - 30m 20 - 40m 30 - 50m 40 - 60m Your score is The average score is 39% LinkedIn Facebook Twitter 0% Admin02/08/20240 197 Less than a minute
