Mine Ventilation - Study Mode

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[#256] The fan drift pressure readings and fan quantities are measured to be 500 Pa and 65 m 3 /s respectively at the time when NVP aids fan pressure. On reversal, the fan delivers a quantity of 50 m 3 /s while acting against NVP with fan drift pressure of 600 Pa. Assuming that the NVP remains constant in both cases the total resistance of the mine in Ns 2 /m 8 will be

(A) 0.9487

(B) 0.2750

(C) 0.4105

(D) 0.1635

Correct Answer

(D) 0.1635

[#257] Samples of air collected in the intake and return gate roads of an advancing long wall face show 0.25% and 0.75% CH 4 , respectively. The panel has a production of 400t in an 8 hour shift when an air quantity of 18 m 3 /s passes through it. Then the methane emission in m 3 /te of coal mined is

(A) 0.02

(B) 0.81

(C) 2.25

(D) 6.48

Correct Answer

(D) 6.48

[#258] The type of fire extinguisher that must NOT be used in case of fire in an electric substation located in an underground metal mine is

(A) Multi-purpose dry chemical extinguisher

(B) CO 2 snow extinguisher

(C) Dry chemical powder extinguisher

(D) Foam extinguisher

Correct Answer

(D) Foam extinguisher

[#259] The S.I. unit of barometric pressure is

(A) Pa

(B) Mpa

(C) Kpa

(D) K

Correct Answer

(C) Kpa

[#260] Barometric pressure is expressed in

(A) mm of kg

(B) mm of Hg

(C) mm of Hg 2

(D) mm of cm

Correct Answer

(B) mm of Hg