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.
Correct Answer :
D. Increases, becomes stable and then decreases.
Related Questions
Two streams of liquid metal which are not hot enough to fuse properly result into a casting defect known as
Cold shut
Swell
Sand wash
Scab
In hot machining, the work is heated by
Simple heating
Flame heating
Induction heating
Any one of these
A CNC vertical milling machine has to cut a straight slot of 10 mm width and 2mm depth by a cutter of 10 mm diameter between points (0,0) and (100,100) on the XY plane (dimensions in mm). The feed rate used for milling is 50 mm/min, milling time for the slot (in seconds) is
120
170
180
240
The purpose of jigs and fixtures is to
Increase machining accuracy
Facilitate interchangeability
Decrease expenditure on quality control
All of these
The floating position of the holding fixture in a rotary transfer device is used to
Improve the accuracy of location
Reduce the tendency to over-index
Improve upon the acceleration and deceleration characteristics
Reduce the cycle time
The mechanism of material removal in EDM process is
Melting and Evaporation
Melting and Corrosion
Erosion and Cavitations
Cavitations and Evaporation
Crater wear leads to
Increase in cutting temperature
Weakening of tool
Friction and cutting forces
All of these
The main purpose of a boring operation, as compared to drilling, is to
Drill a hole
Finish the drilled hole
Correct the hole
Enlarge the existing hole
In metal cutting, use of low feeds and high cutting speeds is desired when the objective is
High metal removal rate
Dry machining
Use of soft cutting tool
Surface finish
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
In metal machining, the work-tool contact zone is a zone where heat is generated due to
Plastic deformation of metal
Burnishing friction
Friction between the moving chip and the tool face
None of the above
Which of the following statement is incorrect with reference of lathe cutting tools?
The flank of the tool is the surface or surfaces below and adjacent to the cutting edges
The nose is the corner, arc or chamfer joining the side cutting and the end cutting edges
The heel is that part of the tool which is shaped to produce the cutting edges and face
The base is that surface of the shank which bears against the support and takes tangent pressure of the cut
What is the type of shielding gas for GTAW (Gas Tungsten Arc Welding) used for carbon steels only called?
Argon H₂
Argon CO₂
Argon Helium
Helium
A fine grained grinding wheel is used to grind
Hard and brittle materials
Soft and ductile materials
Hard and ductile materials
Soft and brittle materials
What is the type of welding defect caused due to poor deposition of weld rod is called?
Porosity
Undercut
Under fill
Crack
A process of removing metal by pushing or pulling a cutting tool is called
Up milling
Down milling
Forming
Broaching
As tool and work are not in contact in EDM process
No relative motion occurs between them
No wear of tool occurs
No power is consumed during metal cutting
No force between tool and work occurs
Which of the following engineering materials is the most suitable candidate for hot chamber die casting?
Low carbon steel
Titanium
Copper
Tin
In a single point turning operation with a cemented carbide and steel combination having a Taylor exponent of 0.25, if the cutting speed is halved, then tool life will become
Half
Two times
Eight times
Sixteen times
The abrasive recommended for grinding materials of low tensile strength is
Silicon carbide
Aluminium oxide
Sand stone
Diamond
For generating a Coons surface we require
A set of grid points on the surface
A set of grid control points
Four bounding curves defining the surface
Two bounding curves and a set of grid control points
The angle between the shear plane and __________ is called shear angle.
Work surface
Tool face
Machine surface
None of these
In metal machining, the zone where the maximum heat is generated due to the plastic deformation of metal, is called
Friction zone
Work-tool contact zone
Shear zone
None of these
The primary purpose of a sprue in a casting mould is to
Feed the casting at a rate consistent with the rate of solidification.
Act as a reservoir for molten metal
Feed molten metal from the pouring basin to the gate
Help feed the casting until all solidification takes place
In transverse grinding
The work is reciprocated as the wheel feeds to produce cylinders longer than the width of wheel face
The work rotates in a fixed position as the wheel feeds to produce cylinders equal to or shorter than the width of wheel face
The work is reciprocated as the wheel feeds to produce cylinders shorter than the width of wheel face
The work rotates in a fixed position as the wheel feeds to produce cylinders longer than the width of wheel face
The process of improving the cutting action of the grinding wheel is called
Truing
Dressing
Facing
Clearing
Soft materials can not be economically ground due to
High temperature involved
Frequent wheel clogging
Rapid wheel wear
Low work piece stiffness
Larger than 15° side cutting edge angle
Increases tool life
Decreases tool life
Produces chipping and decreases tool life
Results in excessive stress concentration and greater heat generation
The swing diameter over the bed is ________ the height of the centre measured from the bed of the lathe.
Equal to
Twice
Thrice
One-half
Friction at the tool-chip interface can be reduced by
Decreasing the rake angle
Increasing the depth of cut
Decreasing the cutting speed
Increasing the cutting speed