799. The most suitable machine for drilling holes in rifle barrels is
A.Ultrasonic machining
B.Laser machining
C.Radial drilling machine
D.Deep hole drilling machine

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800. Time taken to drill a hole through a 25 mm thick plate at 300 r.p.m. at a feed rate of 0.25 mm/revolution will be
A.10 sec
B.20 sec
C.25 sec
D.40 sec

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801. A twist drill is specified by
A.An alphabet specifying hole size
B.A number specifying hole size
C.The size of hole it can drill
D.Any one of the above

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802. The metal is removed in drilling operation by
A.Work hardening of metal
B.Compression
C.Shearing
D.Shearing and Extrusion

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803. The optimum lip angle of the twist arill for the work material of mild steel should be
A.108°
B.110°
C.118°
D.120°

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804. The best way to check the sharpness of a drill of tungsten carbide-tipped bit is to
A.Inspect it physically
B.Test hardness
C.Drill a test hole
D.Judge its finish

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805. Quill in connection with drilling machine refers to
A.Drill holding mechanism
B.Rack
C.Keyway
D.Pinion

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