51. Sectionalization of work in Bord and Pillar method has been stipulated in which of the following statutes?
52. To open a mine for deep seated, the cut used is
53. SIVAD unit is mainly used at Indian long wall face to operate
54. What should be the minimum insulation resistance of high power cable?
55. If the RQD of the ore and wall rock are low, the stoping method suitable is
56. In respect of every medical examination under rule 29B, the manager of the mine concerned shall give at least N days prior notice in writing to the persons to be examined. N is given by
57. Dumper arrives at a shovel at a constant rate of 10 per hour. The service rate is constant at 15 per hour. At a time, the expected number of dumpers in the queue is
58. In solid blasting system the maximum charge in a shot hole should not exceed
59. For a shrinkage stope the following data values are given
Insitu tonnage
9000 tonne
Insitu grade
5.2 g/tonne
Average grade of waste
1.4 g/tonne
Loss of ore in the stope
10%
Dilution
20%
The grade at the mill-head in g/tonne is
| Insitu tonnage | 9000 tonne |
| Insitu grade | 5.2 g/tonne |
| Average grade of waste | 1.4 g/tonne |
| Loss of ore in the stope | 10% |
| Dilution | 20% |
The grade at the mill-head in g/tonne is