Mine Environment - Study Mode

[#31] Mine water flowing at 1.5 m 3 /s with 2 mg/l dissolved oxygen, joins river
water flowing at 7 m 3 /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
Correct Answer

(B) 4.0

[#32] Stink damp is synonymous with
Correct Answer

(A) H 2 S

[#33] When the effect of surface temperature on natural ventilation will be less or negligible?
Correct Answer

(B) in deeper mines

[#34] In ambient air of industrial area, the permissible concentration of particulate matter less than 2.5 μm size measured on 24 hours average in μg/m 3 is
Correct Answer

(C) 60

[#35] It is the ratio of the power actually absorbed by the impeller and converted into the head of the power applied to the shaf
Correct Answer

(D) mechanical efficiency