Drilling And Blasting - Study Mode

[#456] Samples of atmosphere from behind the stopping should be collected at intervals, 48 hours after sealing . . . . . . . . interval.
Correct Answer

(B) 8 hours

[#457] The formule for finding Air HP.
Correct Answer

(A) $$frac{{PQ}}{{75}}$$

[#458] Which drivage needs costly head gear structure.
Correct Answer

(D) Shaft

[#459] If return air way is common to two districts and one of the district to be regulated the . . . . . . . . must be placed in intake air way of the split should be regulated.
Correct Answer

(C) Regulator

[#460] Plugs are fixed on the grade line after every
Correct Answer

(C) 3 - 4.5 m