71. Kermesite is the oxysulphide of:

(a) Nickel mineral

(b) Arsenic mineral

(c) Antimony mineral

(d) Bismuth mineral

Answer: (c)

72. Dacite is a:

(a) Calc-alkaline plutonic rock

(b) Calc-alkaline volcanic rock

(c) Oceanic-alkaline rock

(d) Oceanic-tholeiitic basaltic rock

Answer: (b)

73. Bornite is sulphide ore of:

(a) Silver

(b) Copper

(c) Barium

(d) Strontium

Answer: (b)

74. A reservoir of 30 million cubic meters capacity is having provision of 6 million dead storage. The average volume of sediment deposited is 0.15 million cubic meters per year. The estimated time at which the reservoir will be completely filled by the sediment is:

(a) 400 years

(b) 300 years

(c) 200 years

(d) 100 years

Answer: (c)

75. Grouting may be described as:

(a) Injection of suitable material into the rocks to seal the openings

(b) A process of determining the coefficient of water saturation of a material

(c) A process of lining of tunnels to support the pressure exerted by the material in which the tunnel is excavated

(d) It is the process of rock bolting to prevent rock fall

Answer: (a)

76. The rock which is mainly used for roofing and paving in buildings is:

(a) Basalts

(b) Granites

(c) Limestone

(d) Slate

Answer: (d)

77. The method in which the electrical energy produced by the ore body is directly measured and no outside energizing force is required is:

(a) Equipotential method

(b) Gravity method

(c) Self potential method

(d) Magnetic method

Answer: (c)

78. The electrical resistivity method in which the spacing between the electrodes are kept equal is:

(a) Schlumberger method

(b) Wenner method

(c) Equipotential method

(d) Gravity method

Answer: (b)

79. The horizontal openings which are dug in mountainous terrain to explore ore bodies are called:

(a) Pits

(b) Trenches

(c) Adits

(d) Channels

Answer: (c)

80. The water removed from unit volume of aquifer by pumping or drainage and is expressed as percentage volume of aquifer is:

(a) Porosity

(b) Permeability

(c) Specific yield

(d) Specific retention

Answer: (c)