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Reg No.:_______________ Name:__________________________
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
Sixth Semester B.Tech Degree (R, S) Examination May 2024 (2019 Scheme)
Course Code: AUT302
Course Name: MECHANICS OF MACHINERY
Max. Marks: 100 Duration: 3 Hours
PART A
Answer all questions, each carries 3 marks. Marks
1 Define mechanism and machine (3)
2 What is meant by inversion? Name the inversions of a slider crank chain (3)
3 Explain any three types of followers used in cam (3)
4 Explain the purpose of a clutch in automobiles. (3)
5 Define gear train. What are the different types of gear trains? (3)
6 Explain interference in involute gears. (3)
7 Draw and explain the turning moment diagram for a four-stroke engine (3)
8 What do you mean by static balancing and dynamic balancing. (3)
9 Explain the magnification factor in case of forced vibration. (3)
10 What are the different types of vibrations. (3)
PART B
Answer any one full question from each module, each carries 14 marks.
Module I
11 a) Explain any three types of inversion of four bar (4R) chain with detailed figures. (9)
b) Explain Band Brakes with figure. (5)
OR
12 a) Explain the following inversion of single slider crank mechanism, (9)
1) Crank and slotted liver mechanism
2) Whitworth quick return mechanism
b) Explain Internal expanding brakes (5)
Module II
13 Draw the profile of a cam operating a knife-edge follower having a lift of 30 (14)
mm. The cam raises the follower with SHM for 150⁰ of the rotation followed by
a period of dwell for 60⁰. The follower descends for the next 100⁰ rotation of the
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cam with uniform velocity, followed by a dwell period. The cam rotates at a
uniform velocity of 120 rpm and has a least radius of 20 mm. what will be the
maximum velocity and acceleration of the follower during the lift and the
return?
OR
14 a) Explain in detail the following with necessary figures. (9)
1) Single Plate Clutch
2) Multi Plate Clutch
b) Draw and explain the displacement, velocity, and acceleration of a follower (5)
moving with SHM motion.
Module III
15 a) Discuss and prove the law of gearing (5)
b) A pinion having 30 teeth drives a gear having 80 teeth. The profile of the teeth is (9)
involute with 200 pressure angle, 12 mm module, and 10 mm addendum. Find
the length of path of contact, arc of contact and the contact ratio.
OR
16 a) Discuss the expression for the length of path of contact, length of arc of contact (9)
and contact ratio.
b) The number of teeth on each of the two equal spur gears in the mesh are 40. The (5)
teeth have 200 involute profile and the module is 6 mm. If the arc of contact is
1.75 times the circular pitch, find the addendum.
Module IV
17 A shaft carries three rotating masses m1, m2 and m3 are 5 kg, 4 kg and 3 kg (14)
respectively in three different parallel planes at radii r1, r2 and r3 are 60 mm, 70
mm and 80 mm respectively. The angles of the masses m2, m3 measured from
m1 are 900 and 1350. The length of shaft is 700 mm and planes containing
masses are 150 mm apart. Two balancing masses, mx and my, are placed in two
parallel planes XX and YY which are located 100 mm and 600 mm away from
the left hand bearing. Determine the magnitude of balancing masses to be placed
at planes XX and YY and their angular positions. The radii of balancing masses
are 50 mm and 75 mm respectively.
OR
18 The turning moment diagram for a petrol engine is drawn to the following (14)
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scales: Turning moment 1 mm= 5 N-m, crank angle 1 mm= 100. The turning
moment diagram repeats itself at every half revolution of the engine and the
areas above and below the mean turning moment line taken in order are (+)295,
(-)685, (+)40, (-)340, (+)960, (-)270 mm2. The rotating parts are equivalent to a mass
of 36 kg at a radius of gyration of 150 mm. Determine the coefficient of
fluctuation of speed when the engine runs at 1800 rpm.
Module V
19 Derive the response of the damped free vibration system for under-damping, (14)
over-damping, and critical-damping conditions
OR
20 a) Explain logarithmic decrement and also derive the expression for the same (7)
b) Explain the working of the accelerometer, (7)
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