Drilling And Blasting - Study Mode

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[#201] The percentage of extraction of the depth of seam is 300 m and gallery width 4.2 m

(A) 11

(B) 15

(C) 18

(D) 20

Correct Answer

(D) 20

[#202] The thickest coal seam in found in . . . . . . . .

(A) WCL

(B) BCCL

(C) ECL

(D) SECL

Correct Answer

WCL

[#203] It is estimated that in coal mine nearly . . . . . . . . te of air to a sent down in a mine for every te of coal raise.

(A) 5

(B) 2.5

(C) 10

(D) 8

Correct Answer

(A) 5

[#204] A place in a mine is not considered to be adequately ventilated if the fire damp percentage exceed . . . . . . . .

(A) 0.75

(B) 1.25

(C) 1.75

(D) 0.57

Correct Answer

(B) 1.25

[#205] The synchronus induction motor has an advance of improving . . . . . . . .

(A) Speed

(B) Power factor

(C) Quantity

(D) Rotation

Correct Answer

(B) Power factor