Drilling And Blasting - Study Mode
[#326] BCF fire extinguishers use for quenching . . . . . . . . fires.
Correct Answer
(C) Electronic equipment
[#327] The freezing point of nitroglycerin.
Correct Answer
(D) 13°C
[#328] In the coward flammability diagram, the respective percentages of methane and oxygen at the nose limit are
Correct Answer
(C) 5.8, 12.1
[#329] Methods commonly employed for drivage of gallens of coal are . . . . . . . .
Correct Answer
(D) All of these
Explanation
Solution: Definition: Drivage of galleries in coal mining refers to the process of making underground roadways or passages to provide access to coal seams for extraction and transportation. Common methods: Coal cutting machines and drills: Used to cut and break the coal in preparation for loading and transport. Heading machines, continuous miners, augers, and road headers: Mechanized equipment that simultaneously cuts, loads, and transports coal, increasing efficiency. Coal drills and tubs: Traditional methods involving drilling holes for blasting and using tubs for transporting the broken coal. Reason: Different mining conditions, seam thicknesses, and production requirements may call for any of these methods, and all are recognized as standard practices in coal gallery drivage. Conclusion: Since all the listed methods are commonly employed, the correct answer is All of these .
[#330] The reversal of ventilation may be advantages if fire is in . . . . . . . . shaft.
Correct Answer
(A) DC