Drilling And Blasting - Study Mode
[#231] A place is considered to be dangerous due to gas if it is . . . . . . . . or more.
Correct Answer
(C) 1.25%
[#232] The main disadvantage of run-round arrangement is . . . . . . . .
Correct Answer
(B) Large space needed
[#233] Calculate the w.g produced by a 3.2 m diameter fan running at 280 rpm and delivering 7500 m 3 /min. of air, if the blades are radial, density of air 1.2 kg/m 3 .
Correct Answer
(B) 270
[#234] The value of natural ventilation pressure is not considerably affected by
Correct Answer
(D) Chemical composition of mine air
[#235] Sealed canisters have shelf life in gas mask is . . . . . . . . years.
Correct Answer
(B) 2 - 4