Manufacturing Science - Tool Geometry
Exam Duration: 45 Mins Total Questions : 30
In an orthogonal metal cutting operation, rake angle is 10°, uncut chip thickness is 0.127 mm, chip thickness is 0.228 mm. The value of friction coefficient is
- (a)
0.76
- (b)
0.58
- (c)
0.55
- (d)
0.08
In an orthogonal cutting operation, rake angle is 15°, uncut chip thickness is 0.25 mm, chip thickness 0.50 mm and friction coefficient between chip and tool is 0.5. The cutting velocity of operation is 6.35 m/s. The value of shear velocity is
- (a)
6.48 m/s
- (b)
6.32 m/s
- (c)
6.84 m/s
- (d)
6.72 m/s
During turning operation of a steel rod of 150 mm diameter by HSS tool of geometry 0°, 0, 10 0, 8°, 15°, 75 0, 0 at speed 600 rpm, tangential component of cutting force = 1200 N, axial component of the cutting force = 800 N. The value of friction coefficient is
- (a)
0.69
- (b)
0.56
- (c)
0.78
- (d)
0.64
Find the time required to make 6 holes in 40 mm thick plate, where feed is 0.4 mm/rev, cutting speed 66 m/min and hole diameter is 20 mm.
- (a)
34.28 s
- (b)
30.28 s
- (c)
32.28 s
- (d)
33.28 s
In a milling process, cutting speed is 44 mm/min. The cutter having 10 teeth and diameter is 150 mm feed per teeth is 0.25 mm. The table feed is
- (a)
233.33 mm/min
- (b)
240 mm/min
- (c)
260 mm/min
- (d)
208 mm/min
The length of approach in given plain milling operation is
- (a)
20 mm
- (b)
30 mm
- (c)
40 mm
- (d)
25 mm
The length of approach in face milling operation is
- (a)
1.65 mm
- (b)
1.25 mm
- (c)
1.71 mm
- (d)
1.82 mm
The diameter of cutter is 50 mm and width of job is 40 mm. If operation is unsymmetrical face milling, the length of approach distance is
- (a)
30 mm
- (b)
25 mm
- (c)
20 mm
- (d)
40 mm
In orthogonal cutting system
- (a)
the chip flows over the tool face and direction of the chip flow velocity is normal to the cutting edge
- (b)
the maximum chip thickness occurs at the middle
- (c)
the cutting edge of tool is perpendicular to direction of tool travel
- (d)
None of the above
In metalcutting operations, continuous chips are produced while machining
- (a)
brittle material
- (b)
ductile material
- (c)
hard material
- (d)
All of these
In metal cutting operations, discontinuous chips are produced while machining
- (a)
brittle material
- (b)
ductile material
- (c)
hard material
- (d)
None of these
With increase of cutting speed, the built-up edge
- (a)
becomes longer
- (b)
smaller or finally does not form
- (c)
does not depend upon speed
- (d)
None of the above
Tool life is most affected by
- (a)
tool geometry
- (b)
cutting speed
- (c)
feed and depth
- (d)
microstructure of material
Machinability tends to increase as
- (a)
hardness decreases
- (b)
ductility decreases
- (c)
Both (a) and (b)
- (d)
hardness and ductility both increase
Purpose of side rake is to
- (a)
avoid work from rubbing against tool
- (b)
control chip flow
- (c)
break chips
- (d)
Both (a) and (b)
In a cutting operation, the largest force is
- (a)
axial or longitudinal force
- (b)
radial force
- (c)
tangential force
- (d)
force along shear plane
A device which holds and locates a workpiece during an inspection or for a manufacturing operation, is called
- (a)
fixture
- (b)
jig
- (c)
templates
- (d)
None of these
The machining proces in which the metal of work piece is dissolved is
- (a)
chemical machining
- (b)
electro discharge machining
- (c)
ultrasonic machining
- (d)
electro chemical machining
Find the time required to prepare the slot in two cuts, if it is 10 mm deep and 100 mm long with a cutter diameter 80 mm. Table feed is 60 mm/min and cutter rotation speed is 120 rpm.
- (a)
5.27 min
- (b)
4.38 min
- (c)
5.35 min
- (d)
4.47 min
In a grinding operation, wheel is rotating 1500 rpm and work piece travel is 30 m/min. The diameter of wheel is
- (a)
5.64 mm
- (b)
6.36 mm
- (c)
4 mm
- (d)
10 mm
In electrochemical machining, a thin sheet 20 mm x 20 mm x 1 mm is coated by a element having atomic weight 48 and valency is 2. The density of element is 3200 kg/m3. After 5 min, the thickness of the sheet is increased by 2 mm. The value of current in this operation is
- (a)
34311 A
- (b)
35541 A
- (c)
12434A
- (d)
11195A
If in electrochemical machining, the value of current and time of machining is decreased to half of its initial value. The material removal mass is decreased by
- (a)
70%
- (b)
80%
- (c)
85%
- (d)
75%
If drill diameter is 30 mm, then length of approach is
- (a)
12 mm
- (b)
7 mm
- (c)
9 mm
- (d)
6 mm
In a metal cutting operation, rake angle is 15° and shear angle is 36°. The value of shear strain is
- (a)
1.759
- (b)
1.634
- (c)
2.332
- (d)
2.124
During turning process with 7- a - 6 - 6 - 8 - 30 - 1 mm (ASA) tool, the undeformed thickness is 0.2 mm and width of cut is 2.5 mm used. The machining operation is orthogonal, the value of side rake angle is
- (a)
10°
- (b)
12°
- (c)
9°
- (d)
8°
In a cutting operation, shear angle is 30° and undeformed chip thickness is 0.3mm, shear velocity is 3.5 mis, the value of strain rate is
- (a)
4.83 x 103/s
- (b)
6 x 102/S
- (c)
5.83 x 103/s
- (d)
4.44 x 103/s
In a cutting operation, angle of approach is 75 ° and feed is 0.32 mm/rev. The value of undeformed chip thickness is
- (a)
0.31 mm/rev
- (b)
0.33 mm/rev
- (c)
0.34 mm/rev
- (d)
0.35 mm/rev
In a turning operation, depth of cut is 4 mm and side cutting edge angle is1 5°. The value of width of cut is
- (a)
5.65 mm
- (b)
4.14 mm
- (c)
3.36 mm
- (d)
7.35 mm
The tool life equation is given by VT0.5 = constant. If tool life is reduced to one-fourth of its initial life, th'e percentage increase in cutting velocity is
- (a)
100%
- (b)
200%
- (c)
125%
- (d)
80%
In a tool, a table is given as
Tool life (in min) | Cutting velocity (in rpm) |
45 | 900 |
36 | 1200 |
The value of exponent n is
- (a)
1.52
- (b)
1.43
- (c)
1.29
- (d)
1.32