MECHANICAL ENGINEERING
PAPER- I
SECTION A
Answer any four of the following (each answer should confirm to a limit of around 150 words)
A hollow shall has greater strength in bending and higher stiffness in torsion than a solid
shaft of equal weight and same material. Discuss.(10)
What are different types of drives? Give the advantages and disadvantages of belt dives.

Explain what happens when austenite at a temperature above 723°C is cooled down by
quenching.
What are alloy steels? Discuss the effect of chromium and nickel as alloying element on the
properties of steel
Give reasons for the popularity of Carbon Fibre Reinforced Plastics

2. What is meant by critical speed in whirling of shaft? Show that if the speed of rotation of the
shaft is very large compared to natural frequency of the shaft-disc system. the disc lends to
rotate about its centre of gravity as the shall deflects to accommodate the eccentricity (neglect
viscous effect).(3+ 10)
Derive an expression tor the acceleration of the piston of a reciprocating engine.
The following details pertain to a single cylinder vertical engine:
Bore 20 cm, stroke 40 cm. connecting rod length 80 cm, mass of reciprocating part 140
kg, net gas pressure at the piston when the crank angle is 45° 65 N/cm2 And speed of the
engine= 300 rpm. Determine the turning moment on the crank shaft when the crank angle is
45°
The equation of motion of a spring-mass damper system with one degree of freedom
executing forced vibration is given <img src='./qimages/1511-2c.jpg'>
where y is the displacement at any instant t and o is the angular velocity of the driving force.
Determine:
Natural frequency of un-damped free vibrato on
Critical damping co-efficient
Damping ratio
Static deflection
Logarithmic decrement
Angular velocity or damped Free vibration

3. Calculate the change in volume of a cube of steel with sides measuring 15 cm when it is
immersed to a depth of 800 m in sea water which weighs 10 kN/m3 Take E 200 GPa and
Poisson's ratio v=0.28
At a point in a strained material,the resultant stress on a vertical plane is 100 MPa (tensile)
making an angle of 30• (clockwise) with the normal to the plane. 0n the horizontal plane
through the point. the resultant stress is compressive and makes 600 angle (clock wise) with
the normal.
Determine normal and shear stresses acting on the perpendicular planes.
Obtain principle stresses and Principe planes.
Calculate maximum shear stress and normal stress on the planes of maximum shear stress.
On a properly oriented element,show principal planes and planes of maximum shear
stress.(5+10 lO
What is the function of a follower in a cam follower pair? Sketch any four different types of
follower.
The torque exerted on the crank-shaft of a two-stroke engine is
T-12000 1800 sin 20 1600cos 20 N-m
where teta is the crank angle measured from the inner dead centre position. If the resisting
torque is constant determine:
Power developed by the on engine when running at 150 rpm
Angular acceleration of the flywheel when crank has turned 30 0 if the mass moment
of inertia of the flywheel is 212 kg-m3•
A simply supported beam of span 6 m carries a uniformly vaying load whose intensity varies
from zero at the left support A to l2 kN/m run at right support B. Obtain shearing force and
bending moment at section l.5 m and 4.5 m from the end A.

SECTION B

5. Answer any four of the following (each answer should conform to a limit of around 150 words)
What is meant by forecasting? Explain basic exponential smoothing method for forecasting.(2
What do you understand by the term Flexible Manufacturing System Draw the
structure of a modern FMS.(5+
Explain the following;
Degeneracy
Alternative Optima
Unbounded Solutions.
Compare Computer Numerical Control and Direct Numerical Control system.(5
State the importance of flow chart preparation while writing computer software.
What is the use of mixed mode of operations in computer programming?(5+5)

What is meant by mach inab1lity? Explain any four methods that give brood Mach inability

A machine tool is machining a steel block where the 1ength of cut is 80 mm. The length of the
chip is measured after annealing and Straightening as Ls 63 mm The tool is known to have
a rake angle alfa= 40'. Other known conditions Vs=12 m/mim, depth of Cut t 0.02 mm,
horizontal cutting force Fc=1250 N and vertical force F1=430 N. Find the co-efficient of
friction, chip ratio, thickness of chip, shear plane angle and velocity of the chip along the tool
face.
Explain a gas-assisted laser cutting method with a block diagram.(10)
Write the difference between inspection and manufacturing gages(5)

7. What are the objectives of work-centre scheduling?
Mr Young is the Chief Controller of ABC Copy Express, which provides copy Services for
customers. Five customers submitted their orders in the beginning of the Week. Specific
scheduling data are as follows:
<img src='./qimages/1511-7b.jpg'>
All orders require the use of the only computerised colour copying machine. Mr. Young
decides on the processing by using Shortest operation Time rule. Find the total flow time and
mean flow time.
the following schedule for a liability work package done as pan of an accounting audit in a
corporation. Draw the CPM Network and find the CRITICAl PATH through TOTAL FLOAT calculation:
<img src='./qimages/1511-7c.jpg'>

In inventory control procedure,at what conditions,a plant manager will prefer to use a fixed·
order quantity model as opposed to a fixed-time period model Explain.
Explain the dimensions of DESIGN QUALITY with reference to TQM

XYZ Corporation produces 2 product, Unit profit for product A is R.s. and for
product B is R.s. Each must pass through> 2 machines P and Q. Product A requires 20
minutes on machine P and 16 minutes on machine Q. Product B requires 40 minutes on
machine P and lO minutes on machine Q. Machine P is available 400 minutes day, while Q
is available 160 minutes a day. Due to operational set-up, the company must produce at least
2 units of product A and 5 of product B each clay. Units that are not completed in a given day
are finished in the next day: that is portion of a product can be produced in the daily plan
Formulate the linear Programming Problem.
Solve graphically showing all equations to find the most profitable production plan .
How should the resources be allocated?