421. A power saw which employs a continuous looped blade driven by two wheels is known as
A.A power hacksaw machine
B.A circular/saw machine
C.A filing Machine
D.A band saw machine

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422. Average cutting speed in machining mild steel by single point tool of H.S.S
A.10 m/min
B.20 m/min
C.30 m/min
D.40 m/min

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423. Tool life is said to be over if
A.A poor surface finish is obtained
B.Sudden increase in power and cutting force with chattering take place
C.Overheating and fuming due to friction start
D.All of the above

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424. Tool life is most affected by machine
A.Cutting speed
B.Tool geometry
C.Feed and depth
D.Microstructure of material being cut

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425. The spindle speeds of machine tools are usually designed to follow
A.Arithmetical progression
B.Geometrical progression
C.Harmonical progression
D.Logarithmic progression

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426. The best machine for mass production of watch components machined from bar will be
A.Turret lathe
B.Multi spindle automatic lathe
C.Tool room lathe
D.Numerically controlled lathe

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427. The common ratio Φ for spindle speeds in geometrical progression is taken between
A.0.2 to 0.6
B.0.6 to 1.0
C.1.0 to 2.0
D.2.0 to 5.6

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