The mechanism of material removal in EDM process is
Melting and Evaporation
Melting and Corrosion
Erosion and Cavitations
Cavitations and Evaporation
Correct Answer :
A. Melting and Evaporation
Related Questions
When the cutting edge of the tool is dull, then during machining
Continuous chips are formed
Discontinuous chips are formed
Continuous chips with built-up edge are formed
No chips are formed
The type of reamer used for reaming operation in a blind hole, is
Straight fluted reamer
Left hand spiral fluted reamer
Right hand spiral fluted reamer
Any one of these
A drill mainly used in drilling brass, copper or softer materials, is
Flat drill
Straight fluted drill
Parallel shank twist drill
Tapered shank twist drill
Segmental chips are formed during machining
Mild steel
Cast iron
High speed steel
High carbon steel
Glazing in grinding wheels takes place when the
Wheel is too hard or wheel revolves at a very high speed
Wheel is too soft or wheel revolves at a very slow speed
Wheel is too hard and wheel revolves at very slow speed
Wheel is too soft and wheel revolves at a very high speed
Gears can be best produced on mass production by
Shaping
Casting
Forming
Hobbing
In an interchangeable assembly, shafts of size 25.000 -0.0100⁺⁰⁰⁴⁰ mm mate with holes of size 25.000 -0.010⁺⁰⁰²⁰ mm. The maximum possible clearance in the assembly will be
10 microns
20 microns
30 microns
60 microns
Surface grinding is done to produce
Tapered surface
Flat surface
Internal cylindrical holes
All of these
Jigs are used
For holding and guiding the tool in drilling, reaming or tapping operations
For holding the work in milling, grinding, planing or turning operations
To check the accuracy of workpiece
None of the above
A __________ grinding wheel is used to grind soft materials.
Course grained
Medium grained
Fine grained
None of these
The tool may fail due to
Cracking at the cutting edge due to thermal stresses
Chipping of the cutting edge
Plastic deformation of the cutting edge
All of these
The lip angle of a single point tool is usually
20° to 40°
40° to 60°
60° to 80°
None of these
In oblique cutting system, the cutting edge of the tool
May clear the width of the workpiece
May or may not clear the width of the workpiece
May not clear the width of the workpiece
Should always clear the width of the workpiece
The point angle of a drill, for drilling stainless steel, is
90°
118°
135°
150°
Work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles on and 2 cycles off Power supply is at 50 Hz. Calculate R.P.M. and energy requirement of the above circular electrodes assuming effective resistance between electrodes as 100 ohm.
2.17 rpm, 600 joules
6.8 rpm, 6 joules
5.03 rpm, 600 joules
22 rpm, 600 joules
Internal gears can be made by
Hobbing
Shaping with pinion cutter
Shaping with rack cutter
Milling
In order to obtain a surface finish in the range of 0.75 μm to 1.25 μm , the operation used is called.
Grinding
Lapping
Honing
Buffing
The object of caulking in a riveted joint is to make the joint
Free from corrosion
Stronger in tension
Free from stresses
Leak-proof
In a metal arc welding process, a gas metal arc welding with magnetized flux is used and can be done in all the positions i.e. flat position, vertical position or inclined position.
Globular transfer
Spray transfer
GMAW practice
Dip transfer
In metal cutting operations, the shear angle is the angle made by the shear plane with the
Direction of the tool axis
Direction of tool travel
Perpendicular to the direction of the tool axis
Central plane of the workpiece
Which of the following statement is correct for oblique cutting system?
The cutting edge is inclined at an angle less than 90° with the normal to the velocity of the tool.
Frequently, more than one cutting edges are in action.
The chip flows on the tool face at an angle less than 90° with the normal on the cutting edge.
All of the above
The tool life is said to be over if
Poor surface finish is obtained
There is sudden increase in cutting forces and power consumption
Overheating and fuming due to heat of friction starts
All of the above
In _________ operation, the cutting force is maximum when the tooth begins its cut and reduces it to minimum when the tooth leaves the work.
Up milling
Down milling
Face milling
End milling
Cast iron during machining produces
Continuous chips
Discontinuous chips
Continuous chips with built-up edge
None of these
The height of each tooth of a broach is
Same throughout
In progressively decreasing order
In progressively increasing order
None of these
The maximum possible draft in cold rolling of sheet increases with the
Increase in coefficient of friction
Decrease in coefficient of friction
Decrease in roll radius
Decrease in roll velocity
Crater wear occurs mainly on the
Nose part, front relief face and side relief face of the cutting tool
Face of the cutting tool at a short distance from the cutting edge only
Cutting edge only
Front face only
When the temperature of a solid metal increases,
Strength of the metal decreases but ductility increases
Both strength and ductility of the metal decreases
Both strength and ductility of the metal increases
Strength of the metal increases but ductility decreases
The angle between the shear plane and __________ is called shear angle.
Work surface
Tool face
Machine surface
None of these
In a plain milling machine, the table can be moved
Longitudinally
Crosswise
Vertically
All of these