505. The machining action in ultrasonic machining method is achieved by
A.Impact of tool on workpiece
B.Impact of tool on abrasive particles
C.Impact of tool on coolant
D.Abrasive

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506. For mild steel work-piece and carbide tool, maximum material is removed at temperature of
A.Room temperature
B.100°C
C.280°C
D.400°C

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507. Which is false statement about plasma arc machining
A.It is almost equally effective on any metal irrespective of hardness
B.Simple work supports required
C.Metal removal rate can be increased by increasing the gas flow rate
D.Metal properties remain even without shielding

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508. In electro-chemical machining, best surface finish is obtained
A.With low current density
B.With high current density
C.With slow rate of metal removal
D.With high rate of metal removal

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509. Chemical milling operation is carried out on
A.Grinder
B.Milling machine
C.Tank containing etching solution
D.Surface table

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510. Following electrolyte is used in electrochemical machining process
A.Brine solution
B.Kerosene
C.Transformer oil
D.Water

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511. For the machining of tungsten carbide by ultrasonic machining which abrasive is used for maximum machining rate?
A.Silicon carbide
B.Boron carbide
C.Aluminium oxide
D.Glass

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