Introduction To Mining Engineering - Study Mode

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[#351] Which of the following type of SDB is placed outbye of the face?

(A) heavy barriers

(B) light barriers

(C) intermediate barriers

(D) any kind of barriers

Correct Answer

(A) heavy barriers

[#352] If the value of ore is Rs. 600 per tonne, production cost Rs. 400 per tonne, and cost of overburden removal Rs. 50 per m 3 , the break-even stripping ratio in m 3 /tonne is

(A) 4 : 1

(B) 3 : 1

(C) 1 : 3

(D) 1 : 4

Correct Answer

(A) 4 : 1

[#353] A dragline is required to remove 3,00,000 m 3 of rock per month on the bank volume basis. Consider the following data for the dragline operation. Effective working hours per month = 450 Bucket fill factor = 0.8 Cycle time = 65 s Swell factor of the rock = 1.25 The minimum bucket capacity of the dragline in m 3 is

(A) 7.70

(B) 9.63

(C) 12.04

(D) 18.80

Correct Answer

(D) 18.80

[#354] A shearer is deployed in a mine where the specific energy consumption for cutting coal is 800 kJ/m 3 . The specific gravity of coal is 1.2. If the machine produces 700 te/h, the electrical power consumption in kW of the shearer at 65% motor efficiency is

(A) 149.4

(B) 199.4

(C) 219.4

(D) 239.4

Correct Answer

(B) 199.4

[#355] In an underground coal mine, a freshly exposed roof can be supported by a temporary support in the form of

(A) Triangular chocks

(B) Screw props

(C) Safari supports

(D) Hydraulic props

Correct Answer

(C) Safari supports