512. Electro-discharge machining uses the following dielectric fluid
A.Water
B.Acqueous salt solution
C.Sodium hydroxide
D.Kerosene
513. Best coolant and lubricant for brass, copper, bronze and monel metal is
A.Water, soluble Oils or sulphur-based mineral oils
B.Mineral and fatty oils
C.Soluble oil
D.Dry
514. In ion beam machining process, the metal is removed by
A.Sputtering process
B.Pulsed magnetic field
C.Thermoelectric process
D.All of the above
515. The type of the chip produced when cutting cast iron is
A.Continuous
B.Discontinuous
C.With built up edge
D.Any one of above depending on other factors
516. Best coolant and lubricant for steel and wrought iron is
A.Water soluble oils or sulphur-based and mineral oils
B.Mineral an fatty oils
C.Soluble oils
D.Dry
517. Crater wear occurs mainly due to following phenomena
A.Abrasion
B.Diffusion
C.Oxidation
D.Adhesion
518. Chips with built up edge can be expected when machining
A.Hard material
B.Brittle material
C.Tough material
D.Ductile material
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