Exam Details
| Subject | Machine Design | |
| Paper | ||
| Exam / Course | Diploma in Mechanical Engineering | |
| Department | School of Engineering & Technology (SOET) | |
| Organization | indira gandhi national open university | |
| Position | ||
| Exam Date | December, 2015 | |
| City, State | new delhi, |
Question Paper
1. Answer/Select suitable alternative from the given ones:
Toughness for mild steel under uniaxial loading is given by the area under the stress-strain curve upto
proportional limit
yieldpoint
ultimate stress
fracture
The stress produced due to suddenly applied load as compared to gradually applied one is
the Same
double
1·5 times
three times
Two shafts A and B are made of the same material. The diameter of the shaft B is twice that of shaft A The ratio of power which can be transmitted by shaft A to that of shaft B is
1/2
1/4
1/8
1/16
The shearing area of a rectangular key of length thickness and width is
l x t
l x t/2
l x w
l x w/2
The tearing, shearing and crushing efficiency of a riveted joint are 65% and 60%. The joint efficiency is close to
60%
65%
75%
30%
The ratio of the size of the weld in transverse fillet to butt welded joint is
1·0
0·707
sqrt(2)
0·5
Usual taper in cotter is
1 in 25
1 in 8
1 in 30
1 in 15
(viii) Knuckle joints are used to transmit
axial tensile load
axial compressive load·
twisting load
All of the above
Couplings are used to
connect two shafts that are manufactured separately
reduce transmission shock
improve the mechanical flexibility
All of the above
A circular shaft of diameter subjected to torque the maximum shear stress.is
64T/nd^3
32T/nd^3
16T/nd^3
8T/nd^3
2. Design a rectangular key for the following application
A shaft 65 mm diameter transmits power at maximum shear stress of 67 MPa. The shear stress in the key should not exceed 75% of the stress developed in the shaft. The key should be at least 2·5 times strong in crushing compared to shear failure of the key.
3. Design a solid shaft to transmit 20 kW at 870 rpm. The shaft material properties are
Yield strength =390 MPa
Ultimate strength 600 MPa
Factor of strength =2·0.
4. A 100 mm wide and 12·5 mm thick plate is joined to another plate by two parallel fillet welds. A load of 50 kN acts along the axis of the plate. the length of each weld, if the permissible shear stress is 82 MPa.
5. Design the riveted joint.the bracket shown in figure 1. Allowable shear stress is 110 MPa.
<img src='./qimages/13535-5.jpg'>
6. Design a knuckle joint for a tie rod of circular section to sustain a maximum load of70 kN.The ultimate strength of the· rod material is 420 MPa. The ultimate strength in tension and shear of pin material are 700 and 400 MPa, respectively. Use factor of safety of 4·0.
7. Answer any two of the following:
What is overhauling of power screw What is the condition for overhauling?
Define welding. How does welding joint differ from riveted joint?
What do you mean by alloy steel? Write the effect of the following elements on steel
Nickel
Chromium
8. Write short notes on any two of the following:
Heat Treatment Process
Cotter Joint
Design of Screw and Nut
Couplings
Toughness for mild steel under uniaxial loading is given by the area under the stress-strain curve upto
proportional limit
yieldpoint
ultimate stress
fracture
The stress produced due to suddenly applied load as compared to gradually applied one is
the Same
double
1·5 times
three times
Two shafts A and B are made of the same material. The diameter of the shaft B is twice that of shaft A The ratio of power which can be transmitted by shaft A to that of shaft B is
1/2
1/4
1/8
1/16
The shearing area of a rectangular key of length thickness and width is
l x t
l x t/2
l x w
l x w/2
The tearing, shearing and crushing efficiency of a riveted joint are 65% and 60%. The joint efficiency is close to
60%
65%
75%
30%
The ratio of the size of the weld in transverse fillet to butt welded joint is
1·0
0·707
sqrt(2)
0·5
Usual taper in cotter is
1 in 25
1 in 8
1 in 30
1 in 15
(viii) Knuckle joints are used to transmit
axial tensile load
axial compressive load·
twisting load
All of the above
Couplings are used to
connect two shafts that are manufactured separately
reduce transmission shock
improve the mechanical flexibility
All of the above
A circular shaft of diameter subjected to torque the maximum shear stress.is
64T/nd^3
32T/nd^3
16T/nd^3
8T/nd^3
2. Design a rectangular key for the following application
A shaft 65 mm diameter transmits power at maximum shear stress of 67 MPa. The shear stress in the key should not exceed 75% of the stress developed in the shaft. The key should be at least 2·5 times strong in crushing compared to shear failure of the key.
3. Design a solid shaft to transmit 20 kW at 870 rpm. The shaft material properties are
Yield strength =390 MPa
Ultimate strength 600 MPa
Factor of strength =2·0.
4. A 100 mm wide and 12·5 mm thick plate is joined to another plate by two parallel fillet welds. A load of 50 kN acts along the axis of the plate. the length of each weld, if the permissible shear stress is 82 MPa.
5. Design the riveted joint.the bracket shown in figure 1. Allowable shear stress is 110 MPa.
<img src='./qimages/13535-5.jpg'>
6. Design a knuckle joint for a tie rod of circular section to sustain a maximum load of70 kN.The ultimate strength of the· rod material is 420 MPa. The ultimate strength in tension and shear of pin material are 700 and 400 MPa, respectively. Use factor of safety of 4·0.
7. Answer any two of the following:
What is overhauling of power screw What is the condition for overhauling?
Define welding. How does welding joint differ from riveted joint?
What do you mean by alloy steel? Write the effect of the following elements on steel
Nickel
Chromium
8. Write short notes on any two of the following:
Heat Treatment Process
Cotter Joint
Design of Screw and Nut
Couplings
Other Question Papers
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Subjects
- Applied Thermal Engineering
- Automobile Engineering
- Basics of Thermal Energy
- CAD / CAM
- CNC Machanics
- Computer Integrated Manufacturing
- Engineering Materials
- Machine Design
- Manufacturing Processes-I
- Manufacturing Processes-II
- Manufacturing Processes-III
- Metrology and Instrumentation
- Power Plant Engineering
- Theory of Machine