Model Question Paper
Mechanical Engineering Board
Fourth Semester
2010-2011
THEORY OF MACHINES
Max.Marks:100 Time: 3Hrs
Note : 1. Question No.1 is compulsory
2. Answer any two full questions from each of the remaining sections
3. Any missing data may be suitably assumed
1. a) Fill in the blanks with appropriate word /words 5x1=5
i) Hydraulic press is a __________ link.
ii) Type writer constitutes a __________
iii) The size of the cam depends on ______________ circle.
iv) The product of diametrical pitch and circular pitch is equal to________
v) The brakes are commonly used in cars___________
b) Describe with a neat sketch single plate clutch . 5
SECTION-I
2. a) Define Theory of machines . 2
b) Explain three types of constrained motions. 6
c) Describe with a neat sketch , the crank and slotted lever quick return motion
mechanism. 7
3. a) Explain with a neat sketch ,Scotch yoke mechanism . 6
b) What is pivot bearing ? Give its applications. 4
c) A conical pivot bearing supports a vertical shaft of 200 mm diameter. It is
subjected to a load of 30 KN. The angle of the cone is 120 degree and the
co-efficient of friction is 0.025 .Find the power lost in friction, when the speed
is 140 rpm, assuming uniform pressure condition. 5
4. a) What is the function of clutch ? 2
b) Differentiate between brake and clutch . 5
c) A multiple disc clutch has five plates having four pairs of active friction
surfaces . If the intensity of pressure is not to exceed 0.127 N / sq. mm ,find the
Power transmitted at 500 rpm .The outer and inner radii of friction surfaces
Are 125 mm and 75 mm respectively. Assume uniform wear. 8
SECTION-II
5. a) List the types of belt drives . 3
b) Explain what do you understand by “Initial Tension in a belt” . 2
c) An open belt running over two pulleys 240 mm and 600 mm diameters connects
two parallel shafts 3 m apart and transmit 4 kw from the smaller pulley that
rotatates at 300rpm .The co-efficient of friction between the belt and pulley is 0.3 and the safe working. Tension is 10 N /mm width. Determine the
i) minimum width of the belt ,
ii) initial tension and
iii) length of belt required . 10
6 a) List the classification of toothed wheels. 2
b) Explain with a neat sketch ,the compound gear train . 7
c) Draw the nature of displacement, velocity and acceleration diagrams ,when the
follower moves with SHM . 6
7 a) Define the following terms related to radial disc cam .
i) Base circle ii) Prime circle & iii) Pitch circle 3
b) Why the Roller follower is preferred over the knife edge follower. 2
c) Draw the profile of the cam with knife edged follower is raised through a distance
of 30 mm in 1 / 3 rd of revolution of the cam and is lowered in 1 / 3 rd revolution
with equal intervals between these movements .The follower must move with the
following data
Out stroke-----SHM
Return stroke---Constant acceleration. 80 degree & constant retardation. 40 degree . 10
SECTION-III
8. a) What is the function of a Governor ? 2
b) Define the following terms used in Governors
i) Height of the governor
ii) Mean equilibrium speed
iii) Sleeve lift 5
c) Explain with a neat sketch ,the working of Centrifugal governor. 8
9 a) Explain the different types of Free vibrations with sketches . 10
b) What do you mean by balancing ? 2
c) Explain the balancing of single rotating mass by a single mass in the same plane 3
10 a) Briefly explain static balancing . 3
b) A shat carries two rotating masses 5 kg and 2 kg attached at radii 300 mm and
600 mm respectively from axis of rotation .The included angle between two radii
is 60 degree ,find the angular position and radius of rotation of balance mass if its
mass is 3 kg . If no balance mass is used ,what is the out of balance force on shaft
bearing at 400 rpm. 4
c) Four masses m1,m2 ,m3 & m4 are 200 kg ,300 kg ,240 kg &260 kg respectively.
The corresponding radii of rotation are 200 mm , 150 mm ,250 mm ,& 300 mm
respectively and the angles between successive masses are 45 degree ,75 degree
& 135 degree .Find the position and magnitude of the balance mass required by
graphical method , if its radius of rotation is 200 mm .
