Mine Environment MCQ

Test your knowledge with important Mine Environment MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Mine Environment MCQs at Bissoy

• This is a British instrument that works on tyndall effect and comprises of a collimated beam of near-infra red light passing through a dust chamber. Identify the instrument
  ক

  tyndalloscope

  খ

  simslin

  গ

  holographic counter

  ঘ

  royco particle counter
• In ambient air of an School locality, the permissible concentration of PM₁₀ measured on 24 hours average in μg/m³ is
  ক

  50

  খ

  150

  গ

  75

  ঘ

  100
• What are the composition of the solution in which the plates of the Oldham cap lamp battery remain immersed?
  ক

  HNO₃ + HCL

  খ

  HCL + H₂O

  গ

  H₂SO₄ + distilled water

  ঘ

  Lead solution
• As per Indian law the methane concentration should not exceed "A%" in any part of the mine. A is given by
  ক

  0.5%

  খ

  0.75%

  গ

  1%

  ঘ

  1.25%
• Noise in fans is a function of A. Where A is given by
  ক

  rotational speed

  খ

  fan blade number

  গ

  quality of air velocity

  ঘ

  fan stator
• Electrostatic precipitator works on the principle of
  ক

  Capacitance change

  খ

  Ionisation of the particles

  গ

  Electro heating of gases

  ঘ

  Centrifuging the gaseous molecules
• What do you mean by head co-efficient?
  ক

  It is the ratio of the head at the operating point to Euler's head at zero capacity

  খ

  It is the ratio of the square of the impeller speed to power input

  গ

  it is the ratio of the head developed to the square of the speed

  ঘ

  it is the ratio of the speed to the Euler's head at maximum efficiency
• What is the acoustical power of a 100 hp air compressor whose rated sound power level is 130 dB
  ক

  13 W

  খ

  9 W

  গ

  10 W

  ঘ

  12 W
• The method factor for anemometer reading in duct varies with the
  ক

  roughness of the sides of the airway and the Reynold's number

  খ

  length of the duct

  গ

  velocity of air flowing through the duct

  ঘ

  quantity of air flowing through the duct
• Find the percentage of blackdamp from the mine air sample (pressure by volume) shown below: O₂ = 19.11; N₂ = 79.04; CO₂ = 0.25; CO =0.02; CH₄ =1.58
  ক

  6.1

  খ

  7.1

  গ

  8.1

  ঘ

  9.1
• A fan ventilating a heading through a duct of 750mm diameter circulates 5m³s^-1 of air at the face. Calculate the heat added to the air by the fan, if the input power of the fan is equal to 3kW.
  ক

  1667 J

  খ

  2617 J

  গ

  2917 J

  ঘ

  3317 J
• A filament bulb produces 30 lux illumination at point A as shown in the figure. Assuming that no other source of lighting present in the roadway, the illumination level in lux at point B will be<br><img src="/images/question-image/mining-engineering/mine-environment/1682429398-M2-4-60-20.PNG" title="Mine Environment mcq question image" alt="Mine Environment mcq question image">
  ক

  4.88

  খ

  1.63

  গ

  0.35

  ঘ

  7.00
• At a surface mine office the independent Sound Pressure Level (SPL) measured in dB(A) on account of 3 drill machines are 85,88 and 85. If all the three machines work simultaneously, the combined SPL, in dB (A) is
  ক

  91

  খ

  90

  গ

  92

  ঘ

  94
• A single lamp placed centrally at the roof provides 40 lux illumination vertically below, at the floor of an underground workshop. The workshop of dimensions 20 m × 20 m with height 4m. Assuming uniform spherical dispersion of luminous intensity, the floor level illumination in lux at any corner of the workshop is
  ক

  23.2

  খ

  10.9

  গ

  3.0

  ঘ

  0.8
• A spherical droplet of water, with density 1000 kg/m³ and diameter of 1 μrn, is falling in air. The viscosity of air is 1.85 × 10^-5 kg/m.s. Neglecting air density and assuming that the settling of droplet in air follows Stokes' Law, the settling velocity in m/s is
  ক

  0.98 × 10^-5

  খ

  2.95 × 10^-5

  গ

  8.04 × 10^-5

  ঘ

  53.03 × 10^-5
• A miner when doing hard work at 307 K may sweat at the rate of
  ক

  120 cm³ per hr

  খ

  350 cm³ per hr

  গ

  550 cm³ per hr

  ঘ

  850 cm³ per hr
• If velocity of air in a settling chamber is 0.3 m/s, terminal velocity of the particle is 0.19 m/s then find out h/I ratio of the chamber assuming eddy factor 0.5
  ক

  0.316

  খ

  0.416

  গ

  0.516

  ঘ

  0.616
• In a surface mine, sound pressure level at a location generated by operation of a dozer and a drill respectively are 80 dBA and 60 dBA, when operated independently. The sound pressure generated by the dozer compared to the drill is higher by a factor of
  ক

  10

  খ

  20

  গ

  100

  ঘ

  200
• A worker is exposed to 86 dB for six hours and 92 dB for three hours, giving a nine hour working day. Determine the dose % and TWA.
  ক

  92.3%, 89.4

  খ

  89.4% 69.4

  গ

  89.4%, 86.4

  ঘ

  92.3%, 88.4
• A mine airway 2m wide, 2.5m high and 500m long. The airway passes a quantity of 8m³ per second. Calculate its pressure loss? Assume k = 0.0098 NS²m^-4
  ক

  11 Pa

  খ

  21 Pa

  গ

  31 Pa

  ঘ

  50 Pa
• The noise level at 10 m from a long conveyor belt was 95 dBA. What is the noise level at 100 m?
  ক

  85 dBA

  খ

  90 dBA

  গ

  95 dBA

  ঘ

  80 dBA
• Mine water flowing at 1.5 m³/s with 2 mg/l dissolved oxygen, joins riverwater flowing at 7 m³/s containing 6 mg/l dissolved oxygen. The saturated value of the dissolved oxygen in the mixture is given to be 9.3 mg/l. On the basis, the initial oxygen deficit of the mixture in mg/l is
  ক

  2.4

  খ

  4.0

  গ

  6.8

  ঘ

  14.6
• Precipitation of metallic ions in mine water drainage is carried out by
  ক

  CaSO₄ and MgSO₄

  খ

  CaCO₃ and MgCO₃

  গ

  Ca(OH)₂ and NaOH

  ঘ

  CaCO₃ and MgSO₄
• A waste water effluent has BOD₅ of 80 mg/L and the reaction rate constant is 0.16 per day. The ultimate BOD in mg/L is
  ক

  85

  খ

  100

  গ

  120

  ঘ

  145
• The BOD₅ of an effluent from a coke oven plant is 25 mg/L, and the effluent discharge is 4 ML/d. The receiving stream has a BOD₅ of 2 mg/L and the stream flow is 40 ML/d. What will be the BOD₅ in the stream just below the mixing zone?
  ক

  4.5

  খ

  5.2

  গ

  4.1

  ঘ

  4.8
• Which of the following test is better to carry out before cap test?
  ক

  ignition test

  খ

  accumulation test

  গ

  loop test

  ঘ

  sensitivity test
• What do you mean by gauge pressure?
  ক

  difference between absolute pressure and atmospheric pressure

  খ

  static pressure plus velocity pressure

  গ

  barometric pressure

  ঘ

  absolute pressure only
• In blasting operation, generally 1 Kg of explosive liberates how much litre of CO at STP?
  ক

  10

  খ

  15

  গ

  20

  ঘ

  40
• The permissible value of BOD in the effluent discharge from a coal mines is
  ক

  120 mg/L

  খ

  240 mg/L

  গ

  150 mg/L

  ঘ

  250 mg/L
• What do you mean by vane efficiency?
  ক

  the ratio of actual head to the theoretical head

  খ

  the ratio of the input head to Euler's head

  গ

  the ratio of total head to input head

  ঘ

  the ratio of total head developed to the velocity head