51. In the Draeger Self-contained Breathing Apparatus, used for mine rescue and safety operations, the CO2 gas is absorbed by:

(a) Anhydrous Sodium Hydroxide

(b) Anhydrous Calcium Chloride

(c) Potassium Hydroxide

(d) Potassium Permanganate

Answer: (a)


Answer: (a)

53. The resistance of a mine airway is expressed in terms of the area of an equivalent orifice. If the area of the equivalent orifice is 0.07 square meter, the resistance of the mine airways, to the nearest 10 units, is:

Answer: (a)

54. In shallow mines, the major contributing factor to the direction of natural ventilation is:

(a) Underground temperature

(b) Surface temperature

(c) Underground temperature as well as by surface temperature

(d) No definable dependence on the underground temperature and/or the surface temperature

Answer: (b)

55. For underground mine ventilation, a fan has to be selected basically to cope with the demand of:

1. Pressure of the air to be maintained in the mine ventilation

2. Quantity of air through-put by the ventilation

Which of the above choices is/ are relevant?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c)

56. Which one of the following statements is correct?

(a) Diffusers are fitted to exhaust fans

(b) Evasees are fitted to forcing fans

(c) Diffusers as well as Evasees are fitted to forcing fans

(d) Evasees are fitted to exhaust fans

Answer: (d)

57. In an airway, given that the pressure drop is ΔP and that the quantity of airflow is Q, the resistance of the airway is of:

Answer: (b)

58. Shrinkage stoping operations are not suitable for the following conditions:

1. Mildly sloping deposits

2. Fairly high ore grade

3. Oxidizing characteristics of ore

4. Depths less than 800 𝑚

(a) 1 and 3 only

(b) 1, 2 and 3 only

(c) 1 and 4 only

(d) 1, 2 and 4 only

Answer: (a)

59. Vertical Crater Retreat (VCR) method of mine production requires:

(a) Large parallel downhole drilling

(b) Small diameter upward drilling

(c) Ring pattern drilling

(d) Horizontal and angle drilling

Answer: (a)

60. Shrinkage stoping is suitable for:

1. Thin ore body

2. Thick ore body

Which of the above is/are are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c)