MIICHANICAL INGIN••IUNG


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SEcnONA
Answer any three of the following:
1.(a)The turning moment diagram for a quadruple expansiOn marine engine drawn 10 the following scales: 1 cm 15 ton-m and 1 cm 15°. The areas of the loops above and below the mean turning moment taken in order are 0.12,0.34, 0.91, 0.81, 0.15, 0.18, 1.86 and 1.71cm2 If the moment of interia of the propeller and entrained water is 100ton-m2' and the mean speed of rotation is 100 r.p.m, whatlS the value of the coefficient of f1uctuation of speed?

A compound tube is made by shrinking a thin steel tube on a thin brass tube The areas of cross-section of these tubes are As and Ab, while the young's moduli are Es and Eb,respectively. Show that for any tensile load, the extensiOn of the compound tube is equal to that of a single tube of the same length and total cross-sectional area, but having a Young's modulus of <img src='./qimages/1127-1b.jpg'>
A steel rod of square cross-section is loaded as shown in the figure. <img src='./qimages/1127-1c.jpg'> Find the section which is subjected to maximum stress, its magnitude and nature What will be total change in its length? Take E 200 CPa
What lS a slip system? WhatlS its significance?
Explain the term crystallograhic anisotropy


An automobile filled with a spring loaded Hartnell governor, the f1yballs of it rotate at 500 r.p.m. having radius of rotation of 7cm With sleeve in mid-position and balls arms vertical. The length of ball and sleeve arms is same. The maximum sleeve movements 2cm with ±5% variation in speed. The mass of the sleeve is 5 kg and the friction may be assumed to be equivalent of an additional load of 30 N at the sleeve. The effort of governor lS sufficient to overcome the friction of the sleeve caused by change of speed of mid-position Calculate­ (i)the mass of flyballs;
(ii)the spring rate; the initial compression of the spring; (iv)the governor effort for change of speed; (v)the powe rof governor


The disc of a torsional pendulum has a moment of inertia of 600 kg-cm2 and is immersed in a viscous fluid. The brass shaft attached to it is of 10 cm diameter and 40 cm long. When the pendulum is vibrating, the observed amplitudes on the same Side of the rest position for successive cycles are 6° and 4° Find (i)logarithmic decrement, damping torque at unit velocity and the periodic time of vibration Assume for brass shaft C 44 x 10 10 N/mm. What would be the frequency, if the disc is removed from viscous fluid?
3.(a)A hollow column, 400 mm external diameter and 300mm internal diameter, is hinged at both ends. If the length of column is 5m, E 075 x 105N/mm2, factor of safety Rankin's constant 1/1600 and crushing stress 587 N/mm2, find the safe load the column can carry without buckling. Use Euler's and Rankine formulae.
solid circular shaft running at 110 r.p.m is used to transmit a power of 30 kW and produces safe stress of 80 N/mm2 Find the diameter of shaft. If this shaft is replaced by a hollow shaft having ratio of external diameter to internal diameter of what percentage saving of weight can be achieved, the length and material of the shafts remain same

In a tabulated form briefly outline the procedure, general characteristics and two typical applications of carburizing cyaniding and boronizing processes.
(b)Name any four commonly used reinforcing fibres used in plastic composites. What are their properties and applications?
(c)What elements are generally alloyed to aluminium? What are their effects?
(d)Explain the mechanism of fatigue and creep failures.



SElmON B
Answer any three of the following
an orthogonal cutting operation, the following data have been observed:
Uncut chip thickness 0.127 mm
Width of cut 635 mm
Cutting speed 2m/s
Rake angle 10°
Cutting force 567 N
Thrust force 227 N
Chip thickness 0.228 mm

Determine the shear angle, the friction angle, shear stress along the shear plane and the
power for the cutting operation Also find the chip velocity, shear strain in chip, and the strain
rate.

With the help of a neat sketch, explain the electro hydraulic forming process for making tubular parts and list the variables governing the process What are the main applications of this process?

Explain the difference between operation chart, activity chart, and flow process chart. What are their respective areas of application?

Explain Johnson's procedure for determining an optimal sequence for processing in items on two machines, Determine the optimal sequence of Jobs which minimizes the total elapsed time based on the following information (processing time on machines is given in hours and passing is not allowed): <img src='./qimages/1127-5d.jpg'>

6.(a)With a neat sketch, explain the working of ECM machine. How the machining rate is influenced by
(i)rate of electrolytic flow, (ii)temperature of electrolyte, and
applied voltage? What are the main applications of the process?

(b)Differentiate between point-to-point and continuous path control systems used in NC machines. What are their respective areas of application?

(c)Illustrate the uses of the following preparatory functions:
GO1, G02 and G03

7.(a)Samples of n 8 items each are taken from a manufacturing process at regular intervals. A quality characteristic is measured, and X and R values are calculated for each sample. After 50 samples, we have <img src='./qimages/1127-7a.jpg'> Assume that the quality characteristic is normally distributed. (i)Compute control limits for the X and R control charts All points on both control charts fall between the control limits computed in part(i) what are the natural tolerance limits if the process? if the specification limits are 41+-50 what are your conclusions regarding the ability of the process to produce items within the specifications (iv)Assuming that if an item exceeds the upper specification limit it can be reworked,and if it is below the lower specification limit it must he scrapped,what percent scrap and rework is the process producing? make suggestions as to how the process performance can be improved.

A small electronics company produces pocket calculators and records the demand monthly. the following demand data are for a representative calculator november45;December 57; January 60.using 50 as the first-order exponential smoothing forecast for November forecast February sales with a smoothing constant of 02.is 02 a good choice as a smoothing constant?

A cottage industry produces two types of toys which are sold with a profit margin of Rs.10 for toy1 and toy 2 respectively. the assembly cost and packing cost for one unit of type 1 are Rs.4 and Rs 5 respectively,and corresponding figures for type2 are Rs.5 and Rs 2 the expenditure on assembly and packing is to be kept strictly within and up to Rs 100 amd Rs 80 respectively. using simplex method,calculate the number of toys of each type to be manufactured to get maximum profit.
what is Describe with neat sketches and symbols the types of lay produced by different machining processes.
what is the function of a clamp?Describe the design and operational factors to be considered for proper and adequate clamping of a workpiece.
write a flow chart to solve the quadratic equation ax2+bx+c=0.write also the corresponding C program.