When the metal is removed by erosion caused by rapidly recurring spark discharges between the tool and work, the process is known as
Electrochemical machining
Electro-discharge machining
Ultrasonic machining
None of these
Correct Answer :
B. Electro-discharge machining
Related Questions
The effective number of lattice points in the unit cell of simple cubic, body centred cubic, and face centred cubic space lattices, respectively, are
1, 2, 2
1, 2, 4
2, 3, 4
2, 4, 4
A drill considered as a cutting tool having zero rake, is known as a
Flat drill
Straight fluted drill
Parallel shank twist drill
Tapered shank twist drill
The cutting speed for drilling __________ with high speed steel drills is 24 to 45 m/min.
Mild steel
Copper
Aluminium
Brass
Hardness of green sand mould increases with
Increase in moisture content beyond 6 percent
Increase in permeability
Decrease in permeability
Increase in both moisture content and permeability
A feed gear box for a screw cutting lathe is designed on the basis of
Geometric progression
Arithmetic progression
Harmonic progression
None of these
Crater wear is mainly due to the phenomenon known as
Adhesion of metals
Oxidation of metals
Diffusion of metals
All of these
Which of the following process is used for preparing parts having large curved surfaces and thin sections?
Hot machining
Ultrasonic machining
ECM process
Chemical milling
The relation between the tool life (T) in minutes and cutting speed (V) in m/min is (where n = An exponent, which depends upon the tool and workpiece, and C = A constant)
VnT = C
VTn = C
Vn/T = C
V/Tn = C
Which of the following statement is correct for orthogonal cutting system?
The cutting edge of the tool is perpendicular to the direction of tool travel.
The cutting edge clears the width of the workpiece on either ends.
The chip flows over the tool face and the direction of the chip flow velocity is normal to the cutting edge.
All of the above
In reaming process
Metal removal rate is high
High surface finish is obtained
High form accuracy is obtained
High dimensional accuracy is obtained
Which type of motor is not used in axis or spindle drives of CNC machine tools?
Induction motor
DC servo motor
Stepper motor
Linear servo motor
A coarse grained grinding wheel is used to grind
Hard and brittle materials
Soft and ductile materials
Hard and ductile materials
Soft and brittle materials
The vector sum of cutting velocity and chip velocity is __________ shear velocity.
Equal to
Less than
More than
None of these
Lapping is an operation of
Making a cone-shaped enlargement of the end of a hole
Smoothing and squaring the surface around a hole
Sizing and finishing a small diameter hole
Producing a hole by removing metal along the circumference of a hollow cutting tool
The angle between the shear plane and __________ is called shear angle.
Work surface
Tool face
Machine surface
None of these
The material property which depends only on the basic crystal structure is
Fatigue strength
Work hardening
Fracture strength
Elastic constant
Misrun is a casting defect which occurs due to
Very high pouring temperature of the metal
Insufficient fluidity of the molten metal
Absorption of gases by the liquid metal
Improper alignment of the mould flasks
In orthogonal turning of a low carbon steel bar of diameter 150 mm with uncoated carbide tool, the cutting velocity is 90 m/min. The feed is 0.24 mm/rev and the depth of cut is 2mm. The chip thickness obtained is 0.48 mm. If the orthogonal rake angle is zero and the principle cutting edge angle is 90⁰, the shear angle in degree is
20.56
26.56
30.56
36.56
Which one among the following welding processes uses nonconsumable electrode?
Gas metal arc welding
Submerged arc welding
Gas tungsten arc welding
Flux coated arc welding
In order to have interference fit, it is essential that the lower limit of the shaft should be
Greater than the upper limit of the hole
Lesser than the upper limit of the hole
Greater than the lower limit of the hole
Lesser than the lower limit of the hole
The tail stock set over method of taper turning is preferred for
Internal tapers
Small tapers
Long slender tapers
Steep tapers
It is desired to perform the operations like drilling, reaming, counter-boring etc. on a work piece. Which of the following machine will be used?
Sensitive drilling machine
Radial drilling machine
Gang drilling machine
Multiple spindle drilling machine
Shrinkage allowance on pattern is provided to compensate for shrinkage when
The temperature of liquid metal drops from pouring to freezing temperature
The metal changes from liquid to solid state at freezing temperature
The temperature of solid phase drops from freezing to room temperature
The temperature of metal drops from pouring to room temperature
Internal gear cutting operation can be performed by
Milling
Shaping with rack cutter
Shaping with pinion cutter
Hobbing
The parameter which completely defines the chip formation in a metal cutting process is
Shear angle
Chip-tool contact length
Both (A) and (B)
None of these
The size of abrasive grain required in a grinding wheel depends upon the
Amount of material to be removed
Hardness of material being ground
Finish desired
All of these
In abrasive jet machining, as the distance between the nozzle tip and the work surface increases, the material removal rate
Increases continuously
Decreases continuously
Decreases, becomes stable and then increases.
Increases, becomes stable and then decreases.
For turning small taper on long workpiece, the suitable method is
By a form tool
By setting over the tail stock
By a taper turning attachment
By swivelling the compound rest
Broaching is applied for machining
Internal and external surfaces
Round or irregular shaped holes
External flat and contoured surfaces
All of these
In a shaper, the metal is removed during
Forward stroke
Return stroke
Both the forward and return strokes
Neither the forward nor the return stroke