EOM_1 Bits paper-1

1, In percussive drilling the rock is broken by following action?, 

crushing, 

chipping, 

both, 

noneofabove, 2

2, The drilling rods are made of?, 

castiron, 

steel, 

Ni-cr, 

caststeel, 3

3, Which is used for raising and lowering the rods of square section?,

BUlldog,

sludger,

retainingkey,

none of the above,3

4, Which is used for raising and lowering the rods of circular section?,

Bulldog,

sludger,

corebarrel,

retainingkey,1

5, The sludge or cuttings in the borehole are removed with help of ?

corebarrel,

sludger,

retainingkey,

bulldog,2

6, The device used to catch broken rods under a joint in the borehole?, 

crow's foot or spiral worm,

sludger,

screwfeed,

bulldog,1

7, The operation of tracing the broken and lost parts in the hole and withdrawing them to the surface is known as ...?,

lining the borehole,

drilling,

borehole 

survey,

fishing the borehole,4

8, What is the purpose of lining the borehole?,

to prevent caving of sides,

to prevent water percolation,

to easy drilling operation,

none of the above,1

9, The percussive drilling is applicable upto max depth of ....m?,

200,

300,

500,

700,2

10,Diamond drilling is applicable upto a max depth of .....m?,

500,

1000,

3000,

5000,3

Answers: 1.(2)_2.(3)_3(3)_4.(1)_5.(2)_6.(1)_7.(4)_8.(1)_9.(2)_10.(3)