Mine Ventilation - Study Mode
[#141] Match the followings: Component of flame safety lamp Purpose of component P. Asbestos ring 1. Dissipation of heat of flue gas Q. Wire gauges 2. Formation of air-tight joints R. Outer glass 3. Arrest of explosion inside the lamp S. Combustion chimney 4. Separation of inlet air from flue gas
Correct Answer
(A) P-2, Q-1, R-3, S-4
[#142] Proximate analysis of 50 g of a coal sample shows the following: Moisture = 0.80 g Ash = 7.85 g Volatile matter = 15.90 g The fixed carbon in percentage on a dry, ash free basis is
Correct Answer
83
[#143] A pitot tube is inserted in a ventilation duct with the nose facing the air flow. A vertical U-tube manometer filled with alcohol (specific gravity 0.8) has been used for pressure measurements such that 10.2 mm is read as the total pressure and 8.8 mm as the static pressure. Given the density of air to be 1.2 kg/m 3 , the air velocity at the nose of the pitot tube in m/s is
Correct Answer
(A) 4.27
[#144] Oxygen flow rate in the self contained breathing apparatus Proto Mark IV is
Correct Answer
(C) 2 L/min
[#145] A toxic gas flows into a mine working place at the rate of 2.52 m 3 /min. The concentration of the gas in the intake air is 0.25%. The minimum quantity of intake air in m 3 /min required to dilute the gas to its threshold limit value of 1.0% is
Correct Answer
(D) 336