Manufacturing Science - Forging
Exam Duration: 45 Mins Total Questions : 20
In a hot working process
- (a)
grain structure of metal is refined
- (b)
mechanical properties are improved
- (c)
hardening is eliminated
- (d)
All of the above
In a cold working process
- (a)
ultimate tensile strength and hardness increases
- (b)
good surface finish is obtained
- (c)
internal and residual stresses are developed
- (d)
All of the above
In rolling operations, the roll rotates with a surface velocity
- (a)
lower than the speed of incoming metal
- (b)
exceeding the speed of incoming metal
- (c)
equal to speed of the incoming metal
- (d)
All of the above
Mass production of gears is done by
- (a)
hobbing
- (b)
milling
- (c)
shaping
- (d)
forming
Gear finishing operation is
- (a)
shaping
- (b)
milling
- (c)
hobbing
- (d)
saving or burnishing
Cold or hot rolling does not produce
- (a)
a T-section
- (b)
an I-section
- (c)
a channel section
- (d)
a hollow circular section
Seamless tube can be produced by
- (a)
two high rolling mill
- (b)
upsetting process
- (c)
piercing
- (d)
None of these
In blanking operation, clearan.ce is given in
- (a)
die
- (b)
punch
- (c)
Both (a) and (b)
- (d)
None of these
In piercing operation, clearance is given in
- (a)
die
- (b)
punch
- (c)
Both (a) and (b)
- (d)
None of these
Blanking and piercing operations can be performed simultaneously in
- (a)
progressive die
- (b)
simple die
- (c)
combination die
- (d)
compound die
A 90 mm diameter bar is to be reduced to 60 mm diameter. If depth of cut is 2.5 mm, the number of passes required to be
- (a)
8
- (b)
7
- (c)
6
- (d)
5
Determine the time required for machining a surface of 500 mm x 700 mm on a Shipping machine. The cutting speed is set 8 m/min. The return to cutting ratio is 2 : 3 and feed is 2 mm/cutting stroke. The clearance at each end is 60 mm.
- (a)
40.12 min
- (b)
45.2 min
- (c)
44 min
- (d)
42 min
In open die, forging disc having radius and height 50 mm and 20 mm. After forging radius is 100 mm, the value of true strain is
- (a)
1.386
- (b)
0.693
- (c)
2
- (d)
1
A brass billet is to be extruded from its initial diameter 40 mm to final diameter 20 mm. The extrusion constant is 200 MPa. The force required for extrusion is
- (a)
0.348 MN
- (b)
0.248 MN
- (c)
0.323 MN
- (d)
0.528 MN
In wire drawing operation, diameter of steel wire is reduced from 6 mm to 4 mm. The mean flow of the material is 300 N/mm2 . The ideal force required for drawing is
- (a)
3452 N
- (b)
3506 N
- (c)
3483 N
- (d)
2580 N
A cup of 10 cm height and 5 cm diameter is to be made from a sheet metal of 2 mm thickness. The number of deductions necessary will be (If the limiting drawing ratio of material is 1.9.)
- (a)
1
- (b)
2
- (c)
3
- (d)
4
What is blank diameter of a 3 mm thick sheet to make a cup of height 150 mm and diameter 20 mm?
- (a)
115 mm
- (b)
116 mm
- (c)
111.3 mm
- (d)
115.6 mm
The bend allowance shown in figure is
- (a)
28.26 mm
- (b)
26.26 mm
- (c)
16.26 mm
- (d)
20.26 mm
The force required to make hole as shown in figure is (given て = 400 N/mm2 )
- (a)
1.92 MN
- (b)
2.00 MN
- (c)
1.84 MN
- (d)
1.64 MN
In a rolling process, roll diameter is 400 mm. The thickness of 30 mm strip is to be reduced to 20 mm in single pass. The coefficient of friction is
- (a)
0.170
- (b)
0.158
- (c)
0.163
- (d)
0.252