Diploma- 4th Sem

Course Code: 403

Chapter -1
Q.1. Define the following terms:
i. Kinetics and kinematics
ii. Mechanism, Machine, Structure, kinematic pair and its classification,
iii. kinematic chain
iv. Machine inversions
v. Constrained motion and its types
Q.2. Explain Degree of freedom and find the relation between number of links, number of joints
and number of pairs with the help of Grubler’s and Kutzbach’s criterion of mechanism.
Q.3. Explain all inversion of four bar chain.
Q.4. Explain with sketches all the inversion of single slider crank mechanism.
Q.5. In a crank and slotted lever quick return mechanism the distance of fixed centers are 300
mm and the length of driving crank is 120 mm. Find the ratio of of the time of cutting to the time
of return stroke.
Chapter -2
Q.1. What do you mean by instantaneous centres. Explain in brief.
Q.2. Draw a neat sketch to show determination of velocity and acceleration of slider crank
mechanism by klein’s construction.
Q.3. In a pin jointed four bar mechanism, AB = 300 mm, BC = CD = 360 mm and AD = 600
mm. The angle BAD = 60 degree. The crank AB rotates uniformly at 100 rpm. Locate all the
instantaneous centres and find the angular velocity of the link BC.
Chapter -3
Q.1. Draw the turning moment diagram for four stroke I.C. engine and explain this diagram.
Q.2. In a slider crank mechanism, the length of the crank and connecting rod are 150 mm and
600 mm respectively. The crank position is 60º from inner dead centre. The crank shaft speed is
450 rpm (clockwise). Using analytical method, determine:
 i. Velocity and acceleration of the slider
ii. Angular velocity and angular acceleration of the connecting rod.
Q.3. The turning moment diagram for a multi cylinder engine has been drawn to a scale
1 mm = 600 N.M. vertically and 1 mm = 3º horizontally. The intercepted areas between the
output torque curve and mean resistance line, taken in order from one end, are as follows:
+52, -124, +92, -140, +85, -72 and +107 mm 2. When the engine is running at a speed of
600 rpm. If the total fluctuation of speed is not to exceed ±1.5% of the mean, find the necessary
mass of the flywheel of radius 0.5 m.
Q.4. A horizontal cross compound steam engine develops 300 kW at 90 rpm. The coefficient of
fluctuation of energy as found from the turning moment diagram is to be 0.1 and the fluctuation
of speed is to be kept within ± 0.5% of the mean speed. Find the weight of the flywheel required,
if the radius of gyration is 2 metres.
Chapter -4
Q.1.What is Brake and dynamometer. Define the each type of brake and dynamometer with neat
sketch. Explain the need of brakes and dynamometer.
Q.2. Write the difference between brakes and dynamometer.
Q.3. In a rope brake dynamometer test of an engine the following observation are recorded:
Diameter of brake drum = 1.2 m
Diameter of the rope = 12.5 mm
Spring balance reading = 150 N
Load applied on brake drum = 600 N
Speed of shaft = 200 rpm
Find brake horse power of the engine.
Q.4.A band brake acts on the 3/4th of circumference of a drum of 450 m diameter which is keyed
to the shaft. The band brake provides a braking torque of 225 N-m. One end of the bandis
attached to a fulcrum pin of the lever and the other end to a pin 100 mm from the fulcrum. If the
operation force is applied at 500 mm from the fulcrum and the coefficient of friction is 0.25.
Find the operating force when the drum rotates in the (a) anticlockwise direction and (b)
clockwise direction.
 Chapter -5
Q.1. What are the different types of belt, Rope and chain drive? Classify & explain with suitable
example and sketch it.
Q.2. Drive the expression of tension ratio in flat belt drive. Also drive expression for maximum
power condition in belt drive.
Q.3. Two pulleys, one 450 mm diameter and the other 200 mm diameter are on parallel shaft
1.95 m apart and are connected by a crossed belt. Find the length of belt required and the angle
of contact between the belt and each pulley.
What power can be transmitted by the belt when the larger pulley rotates at 200 rev/min,
if the maximum permissible tension in the belt is 1 kN, and the coefficient of friction between
the belt and pulley is 0.25 ?
Q.4. Determine the width of a 9.75 mm thick leather belt required to transmit 15 kW from a
motor running at 900 rpm. The diameter of the driving pulley of the motor is 300 mm. The
driven pulley runs at 300 rpm and the distance between the centre of two pulleys is 3 metres.
The density of the leather is 1000 kg/m3. The maximum allowable stress in the leather belt is
2.5 Mpa. The coefficient of friction between leather and pulley is 0.3. Assume open belt drive
and neglect the sag and slip of the belt.
Chapter -6
Q.1. What is the function of governor. Classify and explain the construction, working and
derivation with neat sketch. (Such as Watt, Porter & Hartnell governor etc.) Also write the
difference between flywheel and governor
Q.2. Define the following terms:
i. Sensitivity
ii. Stability
iii. Isochronisms
iv. Hunting
v. Effort and Power of governor
vi. Controlling force
Q.3. The arms of a porter governor are each 250 mm long and pivoted on the governor axis. The
mass of each ball is 5 kg and the mass of the central sleeve is 30 kg. The radius of rotation of the
balls is 150 mm when the sleeve begins to rise and reaches a value of 200 mm for maximum
speed. Determine the speed range of the governor. If the friction at the sleeve is equivalent of
20 N of load at the sleeve, determine how the speed range is modified.
Chapter -7
Q.1. Write the function of cam and follower Mechanism. Also classify and define the each type
of the cam and follower with Sketches.
Q.2. A cam is to give the following motion to a knife- edged follower:
(i) Outstroke during 60º of cam rotation; (ii) Dwell for the next 30º of cam rotation;
(iii) Return stroke during next 60º of cam rotation, and (iv) Dwell for the remaining 210º of cam
rotation
The stroke of the follower is 40 mm and the minimum radius of the cam is 50 mm. The
follower moves with uniform velocity during both the outstroke and return stroke. Draw the
profile of the cam when
a. The axis of the follower passes through the axis of the cam shaft
b. The axis of the follower is offset by 20 mm from the axis of the cam shaft.
Q.3. Draw the profile of a cam operating a roller reciprocating follower and with the following
data:
a) Minimum radius of cam is 25 mm
b) Lift of follower is 30 mm
c) Roller diameter is 15 mm
The cam lifts the follower for 120º with simple harmonic motion followed by a dwell
period of 30º. Then the follower lowers down during 150º of the cam rotation with uniform
acceleration and deceleration followed by a dwell period. If the cam rotates at a uniform speed of
150 rpm. Determine maximum velocity and acceleration of the follower during the descent
period.
Chapter -8
Q.1. Explain why the balancing of rotating parts is necessary.
Q.2. Define static and dynamic balancing of rotating parts.
Q.3. Explain need and purpose of balancing.
Q.4. Four masses M1, M2, M3, and M4 are 200 kg, 240 kg and 260 kg respectively. The
corresponding radii of rotation are 0.2 m, 0.15 m, 0.25 m and 0.3 m respectively and the angles
between successive masses are 45º, 75º and 135º. Find the position and magnitude of the balance
mass required, if its radius of rotation is 0.2 m.
Chapter -9
Q.1. What are the different types of vibrations? Explain in brief.
Q.2. Explain critical or whirling speed of shaft.
Q.3. Derive the expression of natural frequency of free longitudinal vibrations.
Chapter -10
Q.1. What are Gears. Also define following terms-
i. Classification of Gears with neat sketch
ii. Neat sketch of gear terminologies and their related terms Such as Pitch circle, Pitch
diameter, Pitch point, Circular pitch, Module, Addendum, Dedendum, clearance etc.
iii. State and prove law of gearing
iv. length of path of contact, length of arc of contact, contact ratio
v. Interference in involute gears
vi. Minimum number of teeth on the gear wheel and the pinion to avoid interference
Q.2. What is gear train? Also define various types of gear train with neat sketch.
Q.3. In an epicyclic gear train, an arm carries two gears A and B having 36 and 45 teeth
respectively. If the arm rotates at 150 rpm in the anticlockwise direction about the centre of the
gear A which is fixed, determine the speed of the gear B. If the gear A instead of being fixed
makes 300 rpm in the clockwise direction, what will be the speed of gear B.
NOTE: All the students are requested that practice all types of numerical problems
from the exam point of view.
List of Experiments (Any five)
1. Study of inversions of four bar chain mechanism
2. Study of inversions of single slider crank chain mechanism:
(a) crank slotted lever mechanism (b) Whitworth quick return motion mechanism
3. Dynamic force analysis of single cylinder four stroke engine
4. Study of flywheel
5. Study of governor
6. Study of different cam and follower
7. Study of different gear trains
8. Study of different types of break and dynamometer