WBUT B. Tech Mechanical Engineering Fifth Semester Design of Machine Elementss (ME-503) Exam - Pa

7/29/2019 WBUT B. Tech Mechanical Engineering Fifth Semester Design of Machine Elementss (ME-503) Exam - Pa

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D)/SElo'-'/ME-503/C7 /@q 3

& MANAGEMENT EXAMINATIONS, DECEMBER _DESIGN OF IT{ACHINE ELEMENTS

SEMESTER - 5sl I Fuil Marks : 7O

GROUP - A( Multiple Choice Type Questlons )

the correct alternatives for the follow'ing : lO x i = iC )ro I .B R.. the fol lowing qype of jornt is preferred for circumferentiai

Iap ointwelded ointr)one of these.

woodruff key is likecylinderspheretapered square.

welded joint the throatabout same sizeabout O.7 Umesabout 0.5 Umesabout 0.25 t imesabout I .25 t imes.

butt jointany one of these

b) semiclrcled) trapezoid

of weld as comDared to slze of weld is

b)ct)

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CS/B.TBCH Ir{E & PE)/SE.}'.-5/WE5O3/O7 /(O8)In thick ryl lnders. the radia l stress across the rhickness of cvi inder isd zero at outside an d maXmunt at ir-rsideb) mi.nimum at outside and maximum at insldec) madmum at outside an d mlnimum at insided) uniform throughoute) none of Lhese.Oldham's coupling is used to connect trvo shafts rvhrjcha) har.'e ateral misalignmentb) whose axes iRtersect at a small anglec) are not in exact alignmentd) is the simplest lype of rigid couplinge) al l of these.MulUple threaded screwsa) increase the efficiencyb) increase the mechanical advantagec) increase the self locking featured) decrease the efficiencye) increase the Ioad lifting capacirv.

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v)

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In the calculatlon of shear stress in helical spring the Wahl's correctjon factorused to take care ofa) comblned effect of transverse shear stress and bending stressb) combined effect of bending stress and curvature of the rvirec) comblned effect of transverse shear stress and curvature of the wired) comblned effect of torslonal shear stress and transverse shear stress i

wlre.An open coll hellcal sprtng is sub.lected to an axial force, Lhe *ire of thesubJected toa) dtrect shear onlyb) comblned shear and bending onlyc) comblned shear, bending and hvisting onlyd) combtned shear and trMstlng only.

l ,spring is

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& Pe ; ;5sg-t /r,tE-543/o7 (oa)l i a shir l t inade of ductr le nl i l ier ia l is srr t r - ;ected o:r r r ) rnenis , , r ' i i i . . 'hoi rhe io i iou. i r :g fa i lure thec:r aluu .'

:.'"'+if;'cc'nr l - r inedbending and iu ' ist i i iE, \ i . ' i r \ i i ldglvr : lhe ConSt: i - \ :1 i t \ /e

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i.rs p.TECEIDdD & PEi,/ EEM-6/I[E-6OS / 07 / (OA)it ts required to destgn a squarepower at 72O rpm ts transmltted5OC4 ( o rr=460 N/mm2 ) and

I s+rr-i

kev for fxing a gear on a shaft of 25 mm dta. 15from the shaft to the gear. The key ls made of sth e factor of safetv is 3. For key material th e ylelc

plate by a single1. The ma;dmum

strengtii in compresston can be assumed to be equal to their yield strenSth in tenslon.Determlne the dlmenslon of the kev( Take stde of the square = O'25 time the shaft dla. )

5. A plate 75 mm wide and 12.5 mm thick ls joined with anotheriransverse *eta anO\ double parallel fillet weld as shown ln the fig.tenslle and shear stress are 70 MPa and 56 MPa respecilvely.

5.

rtg. rFtnd the length of each parallel flllet weld, lf the Jotnt ls subJected to both statlcloadtng and fattgue loadtng. Take stress concentratlon factor for transverse weldas I .5.

A shaft made of mlld steel ls requlred to transmlt l0O kW at 3OO rpm. The supportedlength of the shaft is 3 metres. It carrles two pulleys each welghlng 150 N supportedat a dlstance of I metre from the end respectlvely. Assumlng the safe value of stress,determlne the diameter of the shaft.

:- , ,, ,.r, = ,,,,,*',,'.on*+ #@4;:i'5ilFqiE5!l#!lBmffli EEEt'#**tqtriii'F


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:s,i8 ?'F]ct}r.1,1E& PD)/SELI-a/,UL-5C3i',O'7,i(O',:i' 7

GROUP _ C{ Long Anewer TYPe $ueetlone )

A, 'rsrvei-nv tf i ie questions. : , - , f - 4'5I )es iEn a casr i ron fro lec l i ' . .e , r , r " no.rr t - cc lupl ing to t ransml t I5 kW at 900 r.p. l : ] .J j ro"- , an clectnc iTlo lorLc,r con- l l ressor The senlce factor nrav be assumed as l '35-fhg fol iorr ing permissible stresscs may be used :

Shee.r stl '?ss fo r shatt. bolt and l iey material -inJ-shin{ stress ior b,- , ] r .incl kel ' =' . iea: . .s less f


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CS,/B.TECII IME A i'E)/8rM-S/ME-50s /O7 /(O8l .lJ &!jli:lt

i i . [ i . s requlred to deslgn a Knuck]e Joint as shorvn in Fig. 2. The a-xial orce acl inq othe rod is 15 kN. The fork, eye a-nd he pbr. r re made of plain carbon steel 30 CB *ira tensile rrleld strength of 4O ON/rnm2.11're r:olng:resslve lt:ld strength is tl-e sanle athqt ln tenslon. Shearlngyteld stress is C.577 S'vt. Use a fa ctor of safetw 5 for aU tr"peof load.

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WBUT B. Tech Mechanical Engineering Fifth Semester Design of Machine Elementss (ME-503) Exam - Pa

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