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
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
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
802. The metal is removed in drilling operation by
A.Work hardening of metal
B.Compression
C.Shearing
D.Shearing and Extrusion
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°
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
805. Quill in connection with drilling machine refers to
A.Drill holding mechanism
B.Rack
C.Keyway
D.Pinion
Page 115 of 139