MECHANICAL ENGINGGAING PAPER 1

SECTION A

Attempt any three parts from the following
What do you understand by inversions of a mechanism? Show two inversions of a slider crank mechanism Wlth the help of neal sketches 20

A stepped shall ABC is 0.8 m long For a 1ength AB 0.4 shaft diameter is 40 mm and for length Be 0.4 shaft diameter is 20 mm. Shall" fixed at both the ends A and c. At the Section a torque T 1S applied which causes a maximum shear stress of 100 MPaln stepped shaft. Delenmne the magnitude of torque T

A cantilever ABC, 200 mm long and 20 mm diameter is fixed at end A as shown the above figure. A horizontal axia1 1oad of 10 kN, a vertical load of I kN acts at end C. Torque T applied it section C produces a maximum shear stress of intensity 50 MPa m cantilever
Determine principal stresses at pomt B of cantilever
Give the comp ositi on and applications 0f foll owmg alloys

Mavagmg steel


Invar
Beryllium bronze



Gilunumum bronze


"
In a spnng controlled governor, mass of each govemorballlS 7 kg and moves radially under the action of a controlling force F. If the speed range lS 420 RPM to 440 RPM with range of ball path radius r equal to 12.4 em to 132 em detenrune the lmearrelationship between ball path radius and controllmg force Sketch the graph between F and r WhatlS the equilibnum speedatr=128cm
"

What do you understand by pnmaty balanCIng and secondaty balancmg ofmulticylmder m line engines? ConSider a SiX cylinder mIme engine and show that illS fully balanced
B

o


At a poml A m a stramed malena!, planes AB and AC pass through the poml as shown m the above figure. Nannal and shear stresses on plane AR are 30 MPa and 50 MPa respectively as shown Nannal and shear stresses on plane AC are 60 MPa and 20 MPa respectively as shown By graphical or analytical method, delenmne angle between the planes AB and AC

A beam ABeD, 8 m long, hanged at end A and roller supported at end D cames the
transverse loads as shown m the above figure Delermme the support reactions and draw the
BM diagram for the beam


With the help of neal sketches, differentiale clearly between mlersti tial and sub ,tutiona! sol1d

solutions. Comment on and Au -Ag solid solutions


What do you understand by atonuc packing factor? Detenmne atomiC packing factor for Bee structure


Explam the mechaniSms of


Discontinuous )'lelding m mild steel when tested under tenslOn


HyslereSiS loop for a ductile matenal when subjected to a stress cycle of loading mtenslOn to plastic state unloading, loading m compreSSlOn and then unloading


Givethecompositionsandapplications0fAlumelalloyandNichromealloy




SEcnON D
Attempt any three p arts from the followmg
What is a Master Production Schedule? Explam its relationship with Malena! Plallll1ng capacity plallll1ng and control activiti es
"

Explam with a neal sketch the salient features of Ultrasolllc drilling covenng (il the b as!C op erating pnnaple mecharu sm of metal removal applications


(il List the pnmaty hardware components of a personal compuler


List some of the options for each of the above components
What do you understand from the followmg tenns?

RA1VI ROM 5 GB 860 MHz (el 57.6 KBPS
"
Write a FORTRAN programme to accept data of heights of up to 100 students ofa college The programme should be able to calculate the mam vanance, and standard deviation of hetghts and pnnl
(il thenumberofstudenls
the senal number and heights of mdiVldual students
the mean, vanance and standard deViation 0fhelghts

"

Explam the difference between the followmg two types of motion controls used m CNC machines


Pomtto pomt or positi on control


Contounng or continuous path control Give on example each of thetr application




A stepper motor is used m a CNC positiorung system, for dnvmg the table through a lead screw of pitch 3 mm The control resolution for the table movement is speclfied as 0.01 nun. Detenmne


The number of pulses which the motor should glve per revolution


The Size of step angle 0 f the motor


Thelmeartravelrate of the table
The motor works at a pulse rate of 20 01 s





List three het ght energy rate fonmng processes


What are the lmportant reasons behind the use of these pro cesses?


Explam m detail, usmg a diagram the process of exploSive fonmng of a sphencal dome with a flange from sheet steel
Define the followmg tenns ln rollmg

bite angle


percentage reduction m thickness
elongation coeffiaent



neutral pomt


forward shp


A slab of300 mm mitial thickness, 600 mm WIde lS given a reduction of SO nun In a rolling mill with rolls 1000 nun diameter The spread In this pass lS S nun. Calculate the values of the bite angle, percentage reduction In thi ckness and elongati on co efficient
How lS forward slip detemuned exp enmentally?
Solve the folloWing lmear pro gramnung problem graphi cally or othelWlse Mffil1nuzeZ=4x, lOx, subJect to 2xj, 0
"

What 1s an mventoty Expl am the salient features 0 f the foll oWIng mventoty mo dels Detemumstic models Probabilistic mo dels Model sunder uncertamty


In a detenmmstic model the ordenng COStlS Rs. 4S001 order. The cost of each item IS Rs. 2S00 and canymg COStlS 10%peryear. If the annual reqU1rementlS 10,000 units determme Econonuc Ordenng Quantity If the mventoty canymg cost decreases by 10% and ordenng cost Increases by 10% detemune the change m EOQ. What do you mfer?




List four of the most conunon pnority deCisiOn rules applicable to Jobs to be completed on one smgle machine


Six Jobs are to he processes through the preparation and pamt shops The operation


times are as follows

Job
i




C



Prsptoration
lime HRS





4
Painl.hop lime HRS











Detemune a sequence that WIll mlmnuze the total completion time Find the make span I1me
lux xm I