61. While adopting the Bord and Pillar method, the prime consideration in respect of the panel sizing is:

(a) Incubation period of the coal seam

(b) Depth of coal seam

(c) Thickness of the coal seam

(d) Layout of the face

Answer: (a)

62. Rill stoping method is a form of:

(a) Underhand stoping

(b) Block caving

(c) Artificially supported stoping

(d) Overhand stoping

Answer: (d)

63. Consider the following data related to a dragline:

 Scheduled shift hours = 5000

 Maintenance hours = 1000

 Breakdown hours = 150

What is the percentage availability of dragline?

(a) 85 %

(b) 83 %

(c) 80 %

(d) 77 %

Answer: (d)

64. In opencast mining operation, selective mining is possible with:

(a) Shovel and dumper combination

(b) Dragline

(c) Payloader

(d) Continuous surface miner

Answer: (d)


Answer: (a)

66. In surface mining bucket wheel excavator can give:

(a) Frontal cut

(b) Parallel cut

(c) Terrace cut

(d) Perpendicular cut

Answer: (c)


(a) 3.12 cm

(b) 6.24 cm

(c) 12.4 cm

(d) 31.2 cm

Answer: (a)

68. A rock sample has bulk density of 2.90 𝑔/𝑐𝑐. When its moisture content is 1.40 %, its dry density will be nearly:

(a) 2.59 𝑔/𝑐𝑐

(b) 2.69 𝑔/𝑐𝑐

(c) 2.86 𝑔/𝑐𝑐

(d) 2.96 𝑔/𝑐𝑐

Answer: (c)

69. Increase in moisture content of rock:

(a) Increases its bearing capacity

(b) Decreases its bearing capacity

(c) Has no effect on its bearing capacity

(d) First increases and then decreases its bearing capacity

Answer: (b)

70. Permitted explosives used in blasting off the solid in underground coal mine of degree-1 Gassy seam is:

(a) 𝑃𝑃-1

(b) 𝑃𝑃-3

(c) 𝑃𝑃-5

(d) 𝑃𝑃-4

Answer: (c)