In centreless grinding, the surface speed of regulating wheel is
5 to 15 m/min
15 to 60 m/min
60 to 90 m/min
90 to 120 m/min
Correct Answer :
B. 15 to 60 m/min
Related Questions
Lathe bed is made of
Mild steel
Alloy steel
Pig iron
Chilled cast iron
Broaching is applied for machining
Internal and external surfaces
Round or irregular shaped holes
External flat and contoured surfaces
All of these
The structure of a grinding wheel depends upon
Hardness of the material being ground
Nature of the grinding operation
Finish required
All of these
The maximum production of small and slender parts is done by
Watch maker's lathe
Sliding head stock automatic lathe
Multi-spindle automatic lathe
Capstan lathe
The cutting tool in a milling machine is mounted on
Spindle
Arbor
Column
Knee
Volume of a cube of side l and volume of a sphere of radius r are equal. Both the cube and the sphere are solid and of same material. They are being cast. The ratio of the solidification time of the cube to the same of the sphere is
(4π/6)³ × (r/l)⁶
(4π/6) × (r/l)²
(4π/6)² × (r/l)³
(4π/6)² × (r/l)⁴
Cast iron during machining produces
Continuous chips
Discontinuous chips
Continuous chips with built-up edge
None of these
The operation of making a cone-shaped enlargement of the end of a hole is known as
Counter-sinking
Counter-boring
Trepanning
Spot facing
Glazing in grinding wheels can be decreased by
Using a harder wheel or by increasing the wheel speed
Using a softer wheel or by decreasing the wheel speed
Using a harder wheel or by decreasing the wheel speed
Using a softer wheel or by increasing the wheel speed
Which of the following statement is wrong?
The diamond is the hardest tool material and can run at cutting speeds about 50 times that of high speed steel tool.
The ceramic tools can be used at cutting speeds 40 times that of high speed steel tools.
The cemented carbide tools can be used at cutting speeds 10 times that of high speed steel tools.
The ceramic tools can withstand temperature upto 600°C only.
The ratio between two consecutive spindle speeds for a six-speed drilling machine using drills of diameter 6.25 to 25 mm size and at a cutting velocity of 18 m/min is
1.02
1.32
1.66
1.82
The tool made of cemented carbide wear out faster at
Slow speeds
Medium speeds
Fast speeds
Very fast speeds
The different spindle speeds on a lathe form
Arithmetical progression
Geometrical progression
Harmonical progression
Any one of these
The grade of grinding wheel depends upon
Hardness of the material being ground
Speed of wheel and work
Condition of grinding machine
All of these
The factor responsible for the formation of continuous chips with built up edge is
Low cutting speed and large rake angle
Low cutting speed and small rake angle
High cutting speed and large rake angle
High cutting speed and small rake angle
The aluminium oxide abrasive is chiefly used for grinding
High speed steel
Carbon steel
Wrought iron
All of these
In order to prevent tool from rubbing the work _________ on tools are provided.
Rake angles
Relief angles
Face angles
None of these
The width of cutting edge of a parting off tool varies from
3 to 12 mm
5 to 20 mm
8 to 30 mm
15 to 40 mm
If the flame of the welding torch is directed towards the progress of welding, then what will you call the welding technique?
Forehand welding
Flux cored ARC welding
Electro slag welding
Pulsed spray welding
In machining metals, chips break due to __________ of work material.
Toughness
Ductility
Elasticity
Work hardening
Ultrasonic machining is best suited for
Tool steels
Sintered carbides
Glass
All of these
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
The abrasive recommended for grinding materials of high tensile strength is
Silicon carbide
Aluminium oxide
Sand stone
Diamond
The advantage of a broaching operation is that
Rate of production is very high
High accuracy and high class of surface finish is possible
Roughing and finishing cuts are completed in one pass of the tool
All of the above
In Oxyacetylene gas welding, temperature at the inner cone of the flame is around
3500⁰C
3200⁰C
2900⁰C
2550⁰C
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 soft grade grinding wheels are denoted by the letters
A to H
I to P
Q to Z
A to P
The angle on which the strength of the tool depends is
Rake angle
Cutting angle
Clearance angle
Lip angle
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 hot machining, the work is heated by
Simple heating
Flame heating
Induction heating
Any one of these