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1. STANI MEMORIAL COLLEGE OF ENGINEERING &
TECHNOLOGY, PHAGI – JAIPUR
B.TECH. (VI SEM), II-MID TERM EXAM, MECHANICAL
ENGG. 2018-19
Subject-Design Of Machine Element-II
Time: 2:00 Hrs
MM: 80
Note :- 1) Attempt all questions.
2) All questions are compulsory & carry equal marks.
UNIT-I
Q. 1 A rod of linkage mechanism made of steel 40cr1 (Sut=550N/mm2) is subjected
to a completely reversed load of 100 KN. The rod is machined on a lathe and the
expected reliability of 95%.there is no stress concentration.Determine the diameter
of rod using a factor of safety of 2 for an infinite life condition.
OR
Q.2 A component machines from a plate of thickness ‘t' has ultimate strength 630
N/mm2 .it is subjected to completely reversed axial force of 50 KN. The expected
reliability is 90% and factor of safety is 2. Determine the plate thickness for infinite
life if the notch sensitivity factor is 0.8.
UNIT-II
Q.3 A four stroke diesel engine(C.I ) has the following specifications;
Brake power= 4.5 KW, Speed= 1200rpm, Indicated mean effective pressure
=0.35N/mm2 Mechanical efficiency= 80%. Determine 1. Bore length of the cylinder,
2.Thickness of the cylinder head, sand 3.Size of studs for the cylinder head.
OR
Q.4 Discuss the design of cylinder for an internal combustion engine.
UNIT-III
Q. 5 It is required to design a helical compression spring subjected to a maximum
force of 3000 N, the deflection of the spring corresponding to the maximum force
should be approximately 60mm. the spring index can be taken as 6.The ultimate
tensile strength and modulus of rigidity of the spring material are 690 and 79340
N/mm2 respectively. The permissible shearstress for the spring wire should be taken
as 50% of the ultimate tensile strength.Design the spring and calculate. (1) wire
diameter (2)mean coil diameter(3)total no of coils, F=3000N,
Y=60mm,C=6,F.O.S=2
OR
Q.6 A Pulley made of grey cast iron FG150,transmits 10kw of power at 720 rpm.
The diameter of the pulley is 500 mm. the pulley has four arms of elliptical cross
section,in which the major axis is twice of the minor axis .determine the dimensions
of the cross section of the arm, if the factor of safety is 5.
UNIT-IV
Q.7Explain the following the terms used in bevel gear.
`1)cone distance 2)pitch angle 3)root angle 4)face angle 5)crown height.
OR
Q.8 A Helical pair transmits 20kw with pinion of 20 teeth and 5 module running at
1200 r.p.m ,pressure angle is 200, and the helix angle is 250.determine 1) The
tangential force 2) the radial force 3) the axial thrust.
Assume suitable position of gear.
UNIT-V
Q.9 (a) Mention advantage and disadvantages ofrolling contact bearings.
(b)A ball bearing supporting a gear shaft is subjected to a radial load of 1600 N
and a thrust load of 550 N, select proper bearing for a speed of 150 rpm .life
expectancy is 50x103 cycles.
OR
Q10 Distinguish between ‘’Hydrodynamic bearings and ‘’ Hydro static bearings.