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Total No. of Questions: 09]<"

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< Paper ID [ME301]

[Total No. of Pages: 03

(Please fill this Paper ID in OMR Sheet)

B. Tech. (Sem. - 5th)

MACHINE DESIGN - I (ME - 301)

Time: 04 Hours Maximum Marks :60

Instruction to Candidates:

1) Section - A is Compulsory.

2) Attempt any Four questions from Section - B.3) Attempt any Two questions from Section - C.

Section-AQl) (10 x 2 =20)

a) What do you mean by mechanical engineering design?

b) What basic rules should be followed by the designer for the designprocedure?

c) What is the basic criterion for the selection of material for design?

d) Find the diameter of a rod subjected to maximum tensile load of 65 kNhaving permissible tensile stress 35 N/mm2. -

e) In how many ways a riveted joint may fail?

f) What do you mean by the term" Stress Concentration"?

g) What do you mean by endurance strength?

h) List various types of shaft couplings.

i) ,Whatare the various stresses induced in the shafts?

.1) Howwouldyou findoutthe efficiencyof a rivetedjoint?

Section - B

(4 x 5 =20)

Q2J A single riveted lap joint is to be made of 10 mm plates. Find the diameter ofrivet holes, their pitch and the efficiency of the joint. Take shear stress 64N/mm2, tensile stress 80 N/mm2 and so design the joint that its strength towithstand shear of rivets equals its strength to withstand tearing of 'the plateacross the line of the rivet holes. '

J-9536 P.T.D.

Q3) (a) What are the assumptions made in design of welded joints?

(b) A plate 10 mm wide and 12.5 mm thick is to be welded to another plateby means of.double parallel fillets. The plates are subjected to a sta\cload of 50 kN. Find the length of the weld if the permissible shear stres'sin the weld does not exceed 56 N/mm2.

Q4) What are the various stresses set up in the bolts due to initial tightening?Explain these stresses in details.

Q5) Design and make neat dimensioned sketch of muff coupling which is used toconnect two steel shafts transmitting 40 kW at 350 rpm. The material for the

, shaft is plaincarbonsteel forwhichthe allowableshearstressmaybe takenas 40 N/mm2.The material for the muff is cast iron for which the allowable

shear stress may be assumed as 15 N/mm2.Also check the induced shearstress in the muff with the permissible shear stress.

Q6) Find out the dimensions of a flanged cast iron pipe 300 mm diameter tocarry a pressure of 0.7 N/mm2. Take allowable tensile stress 14 N/mm2 andweisback constant 9 for cast iron.

Section - C(2 x 10 = 20)-

Q7) Design a spigot and socket cotter joint to support a loadvarying from 28 kNin tension to 28 kN in compression. The material used is carbon steel forwhich the following allowable stresses may be used, the load is appliedstatically.Tensilestress== Compressive stress.= 50 N/mm2Shear stress = 35 N/mm2 and Crushing stress = 90 N/mm2.

Q8) A shaft made of plild steel is required to transmit 150 kW at 400 rpm. Thesupported length of the shaft is 3 meters. It carries two pulleys each weighing1500 N supported as the distance of 1 m from the end respectively. Shear

. stress for shaftis 60 N/mm2.Determine the diameter of the shaft.

Q9) A vertical lever ABC 10 mm thick is attached by a fulcrum pin at C and to ahorizontal rod at B as shown in figure.

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An operating force of900 N is applied horizontally at A. Find:a) Reactions at Band C.

b) Tensile stress in the 10 mm diameter tie rod at B.

c) Shear stress in 10 mmdiameter pins at A, Band. C.d) Bearing stress on the lever B.