A solid cylinder of diameter 100 mm and height 50 mm is forged between two frictionless flat dies to a height of 25mm. The percentage change in diameter is
0
2.07
20.7
41.4
Correct Answer :
D. 41.4
Related Questions
In ultrasonic machining, the metal is removed by
Using abrasive slurry between the tool and work
Direct contact of tool with the work
Maintaining an electrolyte between the work and tool in a very small gap between the two
Erosion caused by rapidly recurring spark discharges between the tool and work
Ceramic tools are fixed to tool body by
Soldering
Brazing
Welding
Clamping
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
A solid cylinder of diameter 100 mm and height 50 mm is forged between two frictionless flat dies to a height of 25mm. The percentage change in diameter is
0
2.07
20.7
41.4
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
In oblique cutting system, the maximum chip thickness
Occurs at the middle
May not occur at the middle
Depends upon the material of the tool
Depends upon the geometry of the tool
The obtuse angle, included between the chisel edge and the lip as viewed from the end of a drill, is called
Helix or rake angle
Point angle
Chisel edge angle
Lip clearance angle
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
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
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 structure of a grinding wheel depends upon
Hardness of the material being ground
Nature of the grinding operation
Finish required
All of these
The cutting angle of a flat drill varies from
3° to 8°
20° to 30°
60° to 90°
90° to 120°
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 operation in which oil is permeated into the pores of a powder metallurgy product is known as
Mixing
Sintering
Impregnation
Infiltration
For machining a mild steel workpiece by a high speed steel tool, the average cutting speed is
5 m/min
10 m/min
15 m/min
30 m/min
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
Slow speed of the spindle is necessary in
Thread cutting
Turning a work of larger diameter
Turning a hard or tough material
All of these
The aluminium oxide abrasive is chiefly used for grinding
High speed steel
Carbon steel
Wrought iron
All of these
A better machinable metal is one which gives
Lower chip-tool contact area and larger shear angle
Higher chip-tool contact area and smaller shear angle
Lower chip-tool contact area and smaller shear angle
Higher chip-tool contact area and larger shear angle
The type of tool used on milling machine and broaching machine is
Single point cutting tool
Two point cutting tool
Three point cutting tool
Multipoint cutting tool
The size of a shaper is given by
Stroke length
Motor power
Mass of machine
Rate size
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 increase in depth of cut and feed rate __________ surface finish.
Improves
Deteriorates
Does not effect
None of these
The lip clearance angle is the angle formed by the
Leading edge of the land with a plane having the axis of the drill
Flank and a plane at right angles to the drill axis
Chisel edge and the lip as viewed from the end of a drill
None of the above
A grinding wheel is said to be of _________ if the abrasive grains can be easily dislodged.
Soft grade
Medium grade
Hard grade
None of these
The angle between the face and flank of the single point cutting tool is known as
Rake angle
Clearance angle
Lip angle
Point angle
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
In machining metals, chips break due to __________ of work material.
Toughness
Ductility
Elasticity
Work hardening
The factor considered for evaluation of machinability is
Cutting forces and power consumption
Tool life
Type of chips and shear angle
All 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