Roll No.
Total No. of Questions : 09]
B.Tech.
(AE/ME/IE(2008 Batch)) (Sem.–4)
THEORY OF
MACHINES-II
Subject Code :
ME-204
Paper ID : [A0809]
Time : 3 Hrs.
INSTRUCTION TO CANDIDATES :
1. SECTION-A is COMPULSORY
consisting of TEN questions carrying
TWO marks each.
2. SECTION-B contains FIVE
questions carrying FIVE marks each and
students has to attempt any FOUR
questions.
3. SECTION-C contains THREE
questions carrying TEN marks each and
students has to attempt any TWO
questions.
SECTION-A
l. Write briefly :
i) Write the concept of free body
diagram.
ii) Describe the disadvantage of
unbalance masses of any system.
iii) Write the various sources of
forces in mechanism.
iv) Write the conditions of
complete balancing of reciprocating parts of
an engine.
v) Differentiate between module
pitch and diametral pitch of a gear.
vi) State the conditions of correct
gearing.
vii) Draw the diagrams of compound
and reverted gear trains.
viii) Explain the concept of
gyroscopic motion.
ix) Explain the word synthesis in reference
to mechanism.
x) Differentiate among rack, pinion
and gear.
SECTION-B
2. Describe the graphical method for determining the inertia
forces in a
horizontal
reciprocating engine.
3. Describe the balancing of several unbalance masses
revolving in the same
plane by graphical and analytical
methods with suitable example.
4. Define pressure angle with the help of a neat sketch and
write its
importance in gears. What is the
effect of pressure angle on arc of recess
and arc of approach of two mating
gears?
5. A uniform disc of 100mm diameter and 5 kg is mounted
midway between
bearings
which are 200 mm apart and keep it in a horizontal plane. The
disc spins
about its axis with a constant speed of 1200 rpm counter
clockwise
when viewed right hand side bearing. If the disc process
about the
vertical axis by 50 rpm anticlockwise looking from top, then
find the
resultant reactions at each bearing due to the mass and gyroscopic
effects.
6. Two spiral gears in mesh have the following data
Angle of friction 6°
Normal pitch 20 mm
Shaft angle 55°
Speed ratio 3
Approx. center distance 400 mm
Spiral angle of pinion 25°
Determine (a) exact center distance
(b) number of teeth in each wheel
(c) efficiency of the drive.
SECTION-C
7. State how epicyclical gear train is different from other
gear trains? With the
help of
suitable example, describe the method to analyze epicyclical gear
train.
8. The following data refer to two cylinder locomotive with
crank at 90°
Reciprocating mass per cylinder 300 kg
Crank radius
0.30 m
Driving wheel diameter
1.80 m
Distance between cylinder center
lines 0.65 m
Distance between the driving
wheels central plane 1.55m
Determine (a) the fraction of the
reciprocating masses to be balance, if
the hammer blow is not to exceed
46×103 at 96.5 km/hr (b) the
variation in attractive effort (c) the maximum swaying couple.
9. A four bar mechanism is required such that the input and
output angles
are coordinated as given in the
table:
Input crank angle
|
30°
|
50°
|
80
|
Output follower angle
|
0°
|
30°
|
60
|
Synthesize the mechanism
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