939. To check the diameter of a twist drill with a micrometer, the measurement must be taken across the
A.Margins of The drill
B.Flutes of the drill
C.Cutting edges of the drill
D.Lips of the drill

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940. Commonly used units of feed in drilling operation are
A.Mm
B.Mm/rev.
C.Mm/sec.
D.Mm/min

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941. Annealing is done by cooling in
A.Air
B.Furnace
C.Water
D.Brine

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942. The helical groove in drill is used
A.To dispose chip
B.To admit cutting fluid
C.To save material
D.To present sharp cutting edges

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943. The quickest type of chuck for centering operation is
A.Three jaw
B.Four jaw
C.Pneumatic
D.Magnetic

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944. Metal in electro-chemical grinding operation is removed by
A.Abrasion and shear
B.Electro-chemical decomposition
C.Rusting and melting
D.Electro-chemical decomposition and abrasion

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945. The metal in electro-chemical machining process is removed by
A.Ionisation and shearing
B.Transfer of electrons
C.Chemical action and abrasion
D.Migration of ions towards the tool

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