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Mechanical Engineering Questions and Answers June 10, 2021

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As being the front of an early stage start up, who is just getting inclined towards mass production of a hardware product, list out 5 criteriacharacteristics that a manufacturer(or) vendor should be evaluated based Only mention the points which are other than Quality, Cost and Timeline A small brief against every characteristic would be required.

The homogenous state of stress for a metal part undergoing plastic deformation is given as sigma 10 5 0, 5 20 0, 0 0 10 Distortion energy per unit volume for metal part having 0.3 and E 200GPa is u (Jm).

A rotating beam test specimen when loaded to a stress of 900 MPa gives a life of 1000 load cycles. When loaded to 500 MPa, it withstands 106 cycles. If the required life of the component is 50,000 cycles, what is the maximum stress it can be loaded (cont (a) 645 MPa (c) 600 MPa (b) 831.56 MPa (d) 700 MPa

A component made of steel (Sut 600 MPa, Syt 400 MPa) is to be designed for fatigue loading. The component is to be machined and has a surface finish factor of 0.8 and it has a square cross section of 6mm side, expected reliability is 50. The fatigue stress concentration factor is 1.25. Its endurance strength in shear is (a) 64 MPa (c) 100 MPa

A steel component has the following data Sut 600 MPa, Syt 400 MPa, surface finish factor0.8, size factor 0.75, reliability factor0.8, fatigue stress concentration factor is 1.6. The endurance strength of the component is (a) 144 MPa (c) 154 MPa (b) 60 MPa (d) 90 MPa

The beam shown below carries two external moments. A counter clockwise moment of magnitude 2M acts at point B and a clockwise moment of magnitude M acts at the free end, C. The beam is fixed at A. The shear force at a section close to the fixed end is equal to A (a) 2M L (c) 0 L2 2M B (b) (d) L2 MA L ML JM

The reaction at support A of the beam with uniformly distributed load of intensity w as shown in B (a) 53 w (c) 5 wl 2 wm I. 31 A 3 wm 21 (b) 43 wl (d) 11 w

The bending moment diagram of the beam shown in figure is (a) (c) A 2 mm 5.4 kNm 10.4 kNm 5.4 kNm B 5, kN ari A102030 C BAGIN Are (b) 3 m BA B 10 kNm (d) 5 kNm 15 kNm C B B

If the beam shown in the figure given below is to have zero bending moment at its middle point, the overhang x should be P (N) (a) (c) X wl 4P wl 8P (Nm) mm 1 (b) (d) X 22 6P wl 12P P (N)

A three span continuous beam of span 12m has an internal hinge at B. Section B is at the mid point of AC as shown in figure below. The magnitude of the shear force immediate to the left and immediate to the right of section B are respectively. A 20 kN 2 KN B 4m C 1m 4m 10 kNm Manny D 2m 5 kNm (a) 20 kN and 0 (b) 10 kN and 10 kN (c) 0 and 20 kN (d)

A beam ABCD with simple supports at A, B and D and an internal hinge at C is subjected to loads as shown in figure. The reaction at middle support B is given by 2m 20kN (a) 7.5 kN (c) 20 kN 2m B 1m C 1m 20kN D Im (b) 10 kN (d) 22.5 kN

A beam PQR is loaded as shown in the figure below Which one of the followings represents the correct bending moment diagram a) b) c) d)

Figure shows an elastic beam of constant flexural rigidity El and length L. The transverse deflection v(x) for the beam is represented by an equation v(x)Mo(xxL) (4EIL), where Mo is the applied couple. If L 100 Nmm, then the mm and M 100 magnitude of the shear force (in N) at the middle of the beam is O v(x) L X

A beam is subjected to couples as shown in figure. The maximum shear force and bending moment in the beam respectively are 20 KN 2 m 1 m 20 KN 2 m 20 kN 2 m 20 KN 1 m (a) 20 kN, 20 kNm (b) 10 kN, 20 kNm N (c) 0 kN, 20 kNm (d) 20 kN, 10 kNm

For the beam shown in the figure below, the maximum positive bending moment is equal to negative bending moment. The value of L is, A Li (a) 12 AS AN (c) 2 B wunit length Li (b) (d) SH 22 D

Find the height of the centroid above the axis II for the lamina shown 20 mm 25 mm I A 20 mm 20 mm 20 mm C D B (a) 19.746 mm (c) 20.548 mm 60 mm E (b) 19.989 mm (d) 25.856 mm

If C is the centre of gravity of the lamina shown below, then y is Y T 180 mm K 100 mm 100 mm 200 mm (a) 105.85 mm (c) 109.45 mm 150 mm 200 mm y (b) 108.80 mm (d) 110.95 mm X

Find the maximum stress produced in a round steel bar 60 mm in diameter and 10 m long due to its own weight when it is simply supported at its ends. Steel weighs at 75000 Nm. (a) 1249.99 Nmm (b) 124.9 Nmm (c) 84.96 Nmm (d) 1699.2 Nmm FACE

Two cantilever beams of same length and crosssectional dimensions carry the same load at their free tip, the first beam made of steel and the second of aluminum alloy. The value of E for steel is 3 times that of aluminum alloy. If the maximum bending stress in the steel beam is o, and in aluminum beam is oa, the ratio of os da is (b) 13 (d) 1 (a)

The beam as shown in the figure below is subjected to pure bending by couple Mo. If the cross section is a semicircle, then the ratio of the maximum tensile stress to the maximum compressive stress, (00) is (Round up to two decimal points) Mo L Mo d

A steel bar and an aluminium bar are bonded together to form a composite bar as shown in figure. When the section is subjected to a sagging moment of 280 Nm. E, 2.1105 Nmm, E 7x10 Nmm. Calculate maximum tensile stress in aluminium. 14 mm 14 mm 14 mm m 14 mm (a) 35.13 Nmm (c) 58.18 Nmm Steel PER 42 mm 14 mm (b) 45.16 Nmm (d) 63.21 Nmm

A locomotive axle 250 mm in diameter with outboard bearings is subjected to transverse loads as shown in figure. Determine the maximum bending stress induced in the axle. Take E 2 105 Nmm X W115kN k 340 mm (a) 12.7 Nmm (c) 25.5 Nmm 150 mm W115KN 340 mm 2 (b) 51.2 Nmm (d) 75.9 Nmm

Find the centre of the gravity of a uniform plate in the form of a symmetrical trapezium whose parallel sides are 3 meters and 1.5 meters in length and 2 meters apart.,If it has rectangular extension of the same weight per square meter attached to the 1.5 meters edge and y meters long so as just to fit that edge, find what should be the height y

Find the moment of inertia of the area shaded in figure about the axis AB. B 4 (a) 4292979 mm (b) 4293854 mm (c) 4295883 mm (d) 4297998 mm

A hollow circular section, of external diameter 200 mm and thickness 20mm is to be used as a beam. If the maximum stress permissible in the material is 120 MPa. Find the maximum bending moment the section can carry (a) 55.56 kNm (b) 62.52 kNm 20T SIN 100 (c) 135.6 kNm (d) 142.8 kNm

A beam consists of a symmetrically rolled steel joist. The beam is simply supported at its ends and carries a point load at the centre,of the span. If the maximum stress due to bending is 140 Nmm, find the ratio of the depth of the section to span in order the central deflection may not exceed of 1 480 the span. Take E 2 105 Nmm. 7 125 (a) (c) 9

A wire of 2 mm diameter is wound round a circular shaft of 2 m diameter. What is the normal stress in the wire. Take E 1x105 Nmm. Assume no applied tensile pull on the wire. (a) 500 Nmm 2 Cons (c) 100 Nmm (b) 1000 Nmm (d) 50 Nmm

A prismatic beam of trapezoidal section shown in figure is subjected to sagging B.M Calculate the ratio of b to b for maximum economy if the allowable stresses in tension and compression are 40 Nmm and 50 Nmm respectively. Kb 3 NW T d (a) (c) 212 2 N b n A Idn (b) 23 (d) 2

When a steel wire is bent around a cylindrical drum of radius R 32 cm, the maximum normal strain Emax (in micron) produced in the steel wire of diameter d 116 cm is

A timber beam of rectangular section 100 mm x 60 mm is simply supported at the ends, has a 40 mm x 10 mm steel strip securely fixed to the top surface as shown in the given figure. (Modular ratio 20). k 40 mm Timber 60 mm 100 mm The centroid of the equivalent timber beam in this case from the top surface is (a) 55 mm (c) 28.57 mm (b) 5 mm (d)

An unspecified pure bending moment is used to bend an aluminium rod of radius 2.5 mm elastically bent into a circular ring of radius 2m. If the same bending moment is used to bend elastically a copper rod of radius 2 mm, the radius of the resulting ring (in m) is (EAI70 GPa, Ecu120 GPa) (a) 0.702 (b) 1.404 (c) 1.755 (d) 2.808

Along the length of a beam the extensional as well as compressive strains have been recorded at the top level and 150 mm below it across the depth as 4106 and 1106 respectively. the total depth of the beam is 240 mm. if A1 and A2 are the areas of the cross section under tension and compression, the ratio A1A2 will be ,recorded at the top level and

The ratio of moment carrying capacity of a steel beam of circular cross section. (diameter 40 mm) to that of a square cross section (side length 20 mm) is 3 2 (a) (c) 2 3 2 3 (b) (d) E EN 3 2

A beam is loaded by couples at each of its ends, the magnitude of each couple being 5 kNm. The beam is of steel and its cross section is shown in figure. The maximum tensile stress in the beam, in MPa, is 5 kNm (a) 18.3 (c) 55 5 kNm 84.7 mm NA 40.3 mm INA 7.7106 mm 01 (b) 26.2 (d) 74.32

A vertical pole, cantilevered at the bottom, has a solid circular crosssection of diameter, 25 mm. It is loaded by a horizontal force, P 7 kN at its top end. The maximum shear stress (in MPa) induced in the pole is d

A beam of rectangular section is subjected to transverse loads. In a section where the shear stress at 14 th of the beam depth is 120 MPa, the maximum shear stress is (a) 130 MPa (c) 200 MPa (b) 160 MPa (d) 240 MPa

A rectangular beam 200 mm wide, is subjected to a maximum shear force of 10 kN, producing maximum shear stress of 1 MPa. The depth (in mm) of the beam is

A steel beam of Isection, 200 mm deep and 160 mm wide has 16 mm thick flanges and 10 mm thick web. The beam is subjected to a shear force of 200 kN. Determine the shear stress in web, just at the junction. (when the web is in horizontal). uso imamo M (a) 9.32 Nmm (b) 9.55 Nmm (c) 9.68 Nmmhom (d) 9.83 Nmm

A beam simply supported over a span of 5 m, is loaded with a central point load of 80 kN. The section of the beam is a rectangle, 200 mm wide and 400 mm deep. At a cross section distant 2 m from the support, at a point 75 mm from the N.A. Find the principal stresses (a) 9.844 Nmm (Ten), 4.219 Nmm (comp) (b) 9.844 Nmm (Comp), 4.219Nmm (Ten) (c)

A hollow shaft of 60 mm outer diameter transmits 180 kW of power while rotating at a frequency of 25 hertz. Find the thickness of the shaft so that the shear stress does not exceed 60 Nmm (a) 3.82 mm (c) 4.07 mm (b) 3.98 mm (d) 4.17 mm

An aluminium tube of outer diameter 40 mm and inner diameter 30 mm is 460 mm long. When the tube is subjected to a torque of 650 Nm, the angle of twist is found to be 3.5.,Calculate the maximum shear strain. (a) 0.0026 (b) 0.0030 (c) 0.0032 (d) 0.0039

The propeller shaft of a steam ship has to transmit 7500 kW at 240 r.p.m. The shaft has an internal diameter of 150 mm. Calculate the minimum external diameter if the shearing stress in the shaft is to be limited to 160 Nmm. (a) 230.6 mm (c) 227.8 mm (b) 229.6 mm (d) 226.7 mm

A hollow shaft and a solid shaft constructed of the same material have the same length and the same outer radius R. The inner radius of the hollow shaft is 0.6 R. Assuming that both the shafts are subjected to the same torque, the ratio of the maximum shear stress in the hollow shaft to that in the solid shaft is

A 50 mm diameter shaft is driven at 15 Hz by a motor delivering 35 kW of power. Find the maximum shear stress in the shaft. (b) 15.13 Nmm (d) 25.45 Nmm (a) 14.23 Nmm (c) 21.85 Nmm

A shaft ABC 2.7 m long consists of parts AB and BC of lengths 1.5 m and 1.2 m and diameters 60 mm and 50 mm respectively. The total angle of twist does not exceed 2.5. Take G 8 x 10 Nmm. Find the torque in kNm. A 60 mm dia B 50 mm dia 1.5 m 1.2 m (a) 0.82 kNm (c) 1.11 kNm (b) 0.93 kNm (d) 1.23 kNm T

Figure shows a composite shaft of the same material consisting of parts AC and BC each 625 mm long. The part AC is a solid shaft of 75 mm diameter. The part BC is a hollow shaft whose external and internal diameters are 75 mm and 60 mm respectively. The shaft is fixed at both its ends. A torque To is applied at a section D in BC a distance x from

A solid shaft of 80 mm diameter is transmitting 100 kW power at 200 r.p.m. Calculate the angle of twist in degrees for a length of 6 m. Take N 8 104 Nmm. (a) 1.55 (c) 4.56 (b) 2.89 (d) 5.09

A composite shaft is made of a steel tube with an inner brass core perfectly bonded together as shown in the figure below. The shaft is fixed at one end and subjected to a torque of 2T at the other end. Shear modulus of steel is G and that of brass is G2. The outer radius of the steel tube is R 2r and radius of the inner brass core is r. The

A shaft is to transmit 2800 kW at 220 rpm. 50 MPa, length of shaft 4m and T max G 70 MPa. Then, torque produced by the shaft in kN.m is (a) 64.51 (c) 121.54 (b) 167.19 (d) 145.45

A hollow steel shaft of external diameter 100 mm and internal diameter 50 mm is to be replaced by a solid alloy shaft. Assuming the same value of polar modulus for both, the diameter of the solid alloy shaft will be (a) 103 (b) 109375 mm (c) 9375 mm (d) 10x 9375 mm 9375 10 mm

A double riveted double strap butt joint is made with 15mm thick plates and 20 mm diameter of rivets. The pitch of the joints is 90 mm. Allowable stresses are o 115 o 160 MPa. Oc MPa, T 90 MPa Calculate the efficiency of the joint. (a) 62 (b) 76 (c) 56 (d) 68

A double riveted double strap butt joint is made with 12 mm thick plates and 18 mm diameter rivets. The pitch of the joint is 80 mm. Allowable stresses are ot 115 MPa, t 80 MPa, and o. 160 MPa. The efficiency of the joint is (a) 56 (c) 60 (b) 58 (d) 63

For the block diagram, shown in Figure 1, some parameters are given as y n x n x nM y2 n y ny n 1 In the above equations, the value of M is the month that you were born in (according to your AUST record). For example if your month of birth is June then the value of M should be 6. Find out the transfer function of the combined system (shown in

In a riveted Joint, the diameter of rivet hole is 20 mm. The pitch of the joint is 3.5 times the diameter of rivet hole. The efficiency of the joint is (a) 50 (b) 60 (c) 70 (d) 80

In a riveted joint, the tearing efficiency is 80 and the diameter of the rivet hole is 20mm. The pitch of the joint is (a) 60 mm (c) 120 mm (b) 100 mm (d) 160 mm

Two plates of 7 mm thick are connected by a triple riveted lap joint of ZigZag pattern. The diameter of rivet is 18 mm and pitch of rivet is 80 mm. What is the magnitude and mode of failure of joint Assume, ot 90 MPa, Oc 120 MPa. (a) 30.5 kN (Tear) (b) 30.5 kN (Shear) (c) 39 kN (Tear) (d) 39 kN (Tensile) T 40 MPa and

For eccentric loaded riveted joint as shown in the figure with x 100 mm and permissible shear stress of 60 MPa, determine the diameter of the rivets in mm. X 50mm 50kN (a) 24 mm (c) 21 mm IN X I 1 ww 3 X 1 0001 (b) 25 mm. (d) 22 mm

For the rivetted joint B as shown in the figure, the resulting shear load on heavily loaded rivet is 50 mm B (a) 5 kN (c) 15.81 kN 75 mm 10 kN (b) 15 kN (d) 20 kN

A riveted joint, consisting of two identical rivets is subjected to an eccentric force 10 kN as shown in the figure. The primary and secondary shear loads on the rivet hole are respectively, P P10 KN (a) 0 kN, 5 kN (c) 5 kN, 5 KN 100 (b) 5 kN, 0 kN (d) 5 kN, 10 kN

When two components are initially tightened by a bolt with a pre load of 6 kN, the elongation of the bolt is 2 mm and the compression of the components together is 1 mm. When the assembly is subjected to 9 kN (tensile on the bolt) of external load, what will be the net compression in the components under this load (a) zero (c) 2 mm (b) 0.5 mm (d)

A bolted joint is used to connect two components. The combined stiffness of the components is twice the stiffness of the bolt. The tightening of the nut results in a preload of 6 kN in the bolt. 02. When an external force of 12 kN is applied on the assembly the tension in the bolt is (a) 18 kN (b) 14 kN (c) 10 kN (d) 12 kN 03. The maximum load the

Several members are bolted together on such a manner that the deflection per unit load for the bolted members is the same as for the bolt. What axial external load has to be applied to the bolt to cause separation of the bolted members, if initial tightening load on the bolt is 40 kN (a) 60 kN (c) 100 kN (b) 80 kN (d) 120 kN

A Bracket is fitted to the channel with 4 bolts. The dimension are a b 150 mm and e 300 mm. The allowable shear stress of bolt is 40 MPa. e 08. The resultant maximum shear load is (a) 15 kN (c) 40 kN (b) 25 kN com (d) 50 kN 09. The nominal diameter of the bolt is (a) 20 mm (c) 60 mm (b) 40 mm (d) 80 mm 40 kN

A bolt in a pressure vessel is tightened with a preload of 7000 N. The external load on the bolt varies from 0 to 9000 N. The constant based on stiffnesses of bolt and member is 0.33. Yield strength is 260 MPa. Endurance limit in reversed axial loading is 130 MPa. Stress concentration factor is 2.8. Factor of safety is 3.0. Stress area of the bolt

A 1050, BS070M20 colddrawn steel cantilever bar supports a static load of 1.4 kN as shown in the figure. What are the resultant shear loads on bolt A and bolt B 2547525 O TA e B (a) 6.4 kN, 5 kN (c) 7 kN, 8.4 kN 350 1.4 kN (b) 4.5 kN, 8 kN (d) 8 kN, 9.4 kN .

For joining two plates for eccentric load, four metric bolts with two different configurations were considered as shown below. Which configuration is stronger PLUS CROSS L L (a) Plus configuration (b) Cross configuration (c) Both configurations are equal strength (d) Insufficient data to answer.

A steel plate subjected to a force of 5 kN and fixed to a channel by means of three identical bolts is shown in figure below. The bolts are made of plain carbon steel 30C8 (Syt 400 Nmm) and the factor of safety is 3. The diameter of the shank is,75 75 I N (a) 57 mm (c) 9 mm 250 5kN in od (b) 36 mm (d) 12.73 mm

A bolted joint is used to connect two The combined stiffness of the components is one third that of the bolt. If the bolt is initially tightened to a preload 10 kN. What is the maximum Load the assembly can take without causing clearance between the components (a) 50 kN (b) 40 kN (c) 45 kN (d) 48 kN

A welded connection as shown in figure is subjected to an eccentric load of 10 kN. Size of the weld is 10 mm. What is the primary shear stress and where does it occur 1 B 50mm C 50 1 (a) 141.4 MPa, D (c) 141.4 MPa, B,C 100 A D 10 kN (b) 14.14 MPa, A,B (d) 14.14 MPa, B

A Bracket as shown in figure is welded to a plate. The welds have the same size and the permissible force per mm of weld length is 1 kN. The lengths 1 and 12 are T 7 AWW. 120 kN 10050 120 kN (a) 40 mm, 80 mm (b) 60 mm, 85 mm (c) 75 mm, 90 mm (d) 80 mm, 110 mm 12 151

A 25mm radius and 300mm long shaft is supported at its ends by two journal bearings. A load of 2kN acts on the shaft at a distance of 200mm from the left bearing. The length to diameter ratio for the bearings is 1.5. The maximum bearings pressure induced is (a) 0.53MPa (c) 5.3 MPa (b) 0.35 MPa (d) 3.5 MPa

A shaft running at 900 revmin is supported by bearings 50 mm in diameter and 75 mm in length. The bearings operate in still air. The oil used has a viscosity of 0.013 kgms and the diametral clearance is 0.05 mm. The permissible load corresponding to the heat generation of 35.8 watts is ZN f0.326(Z) (2) (a) 250 N (c) 450 N 0.002 (b) 350 N (d) 550 N

A journal bearing 200mm in diameter and 250mm long is supporting a load of 15kN at 1000rpm. The radial clearance is 0.08 and the bearing dissipates 100kJmin in friction What is the viscosity of oil at the operating temperature (a) 0.00625 Pasec (b) 0.0077 Pasec (c) 0.0023 Pasec (d) 0.008 Pasec

A hydrodynamic journal bearing is subjected to 4 kN load and the bearing pressure is 1.4 MPa. If the diameter of bearing is 50 mm then which of the following bearing is suitable (a) long bearing (b) short bearing (c) square bearing (d) medium bearing

A conical thrust Bearing rotating at 100 rpm is subjected to a thrust load of 10kN. Power lost in watts, if face width 100m, inner and outer diameters are 200mm and 300mm respectively, assume fluid friction cofficient as 0.08. (a) 2094 W (c) 1047 W (b) 2121 W (d) 1061 W

A hydrodynamic journal bearing is subjected to 3000N load at rotational speed of 2000rpm. The bearing diameter and length are 40mm. If radial clearance is 30m and bearing is lubricated with an oil having viscosity 0.04Pas, the Sommerfeld number of bearing is

A ball bearing is subjected to a radial load of 2500 N and an axial force of 1000 N. The catalogue gives the following data Radial factor 0.4, Axial thrust factor 1.5, Static load rating 10000 N, Dynamic load Rating 7500 N. The bearing life in millions of revolutions is (a) 1 (b) 9 (c) 27 (d) 8

A ball bearing subjected to a radial load of 3000 N is expected to have a life of 40 million revolutions with a reliability of 95. If the desired reliability is 50, the life of the bearing in millions of revolution is (a) 200 (b) 260 (c) 320 (d) 370

A bearing has a specific dynamic radial capacity of 40 kN. The desired life is 5000 hours for 90 of the bearings. The equivalent radial load at 400 revmin is (a) 8.11 kN (b) 9.43 kN (c) 10.27 kN (d) 12.56 kN

The friction torque exerted in a single row deep groove ball bearing under a radial load of 30 kN is (Bore is 50 mm and the coefficient of friction is 0.0015.) (a) 1.125 N.m (c) 1.375 N.m (b) 1.257 N.m (d) 1.427 N.m

A ball bearing is subjected to a radial load of 5 kN is expected to have life of 8000 hr at 1450 rpm with reliability of 99 . Life of bearing with 90 reliability is million revolutions.

A ball bearing is subjected to a radial load of 10 kN, and an axial load 4 kN. The shaft rotates at 1200 r.p.m with average life of 5000 hr. is desired inner race rotation. The service factor is 1.5, X 0.48, Y 1.3, V 1 Dynamic load is (a) 36 kN (c) 62.4 kN (b) 71.1 kN (d) 106 kN

A Taper roller bearing has a dynamic load capacity of 26 kN. The desired life for 90 of the bearing is 9000hr and the speed is 300 rpm. Calculate the equivalent radial load that the bearing can carry. (a) 6450 N (c) 6250 N (b) 4320 N (d) 5650 N

A plate clutch consisting of two pairs of contacting surfaces with coefficient of friction 0.2 has a torque transmitting capacity of 600 Nm. The inner and outer diameters of the plates are 200mm and 100mm. What is the axial force required to avoid slip between the plates Assume uniform pressure theory. (a) 77 kN (c) 100 kN (b) 38.6 kN (d) 17.3 kN

In a centrifugal clutch, the radius of center of gravity of the shoes is 80 mm and mass of each shoe is 2 kg. If the engagement starts at 300 rpm, the spring force is (a) 158 N (b) 642.5 N (c) 60 N (d) 2.5 kN

A multi disk clutch, steel and bronze is to transmit 4 kW at 750 revmin. The inner radius of contact is 40 mm and the outer radius of contact is 70 mm. The coefficient of friction is 0.10. The allowable pressure is 350 kPa. (Assume uniform wear) 11. The total disks of steel and bronze are (a) 2 steel and 1 bronze (b) 3 steel and 2 bronze (c) 4

A tentative design for full journal bearing calls for a diameter of 75 mm and a length of 125 mm to support a load of 20 kN. The shaft is to operate at 1000 revmin. It is desired to operate at a bearing surface temperature not to exceed 75C in a room temperature of 35C. The oil used has a viscosity of 0.01 kgms at 115C. Coefficient of friction is

A multipledisc clutch transmits 50 kW of power at 1400 r.p.m. Axial intensity of pressure is not to exceed 0.15 Nmm, and the coefficient of friction for the friction surfaces is 0.12. The inner radius of the disc is 80 mm which is 0.7 times the outer radius. Determine the number of discs required to transmit the given power. Assume uniform wear

A multiple disk clutch and cone clutch have the same mean diameter, operate at the same speed and same axial load is exerted in both clutches. The coefficient of friction is same for both the clutches. The multiple disk clutch has 4 steel disks and 3 bronze disks. The total cone angle of the cone clutch is 20. The ratio of power transmitting

A soft surface cone clutch handles 200 Nm of torque at 1250 rev min. The large diameter of the clutch is 350 mm. The cone pitch angle is 6 the face width is 65 mm 1 4 and the coefficient of friction is 0.20. Assuming uniform wear, the axial force required to transmit the torque is (a) 237 N (b) 437 N (c) 537 N (d) 637 N

An automotive plate clutch consists of two pairs of contacting surfaces. The torque transmitting capacity of the clutch is 550 Nm. The coefficient of friction is 0.25 and the permissible intensity of pressure is 0.5 MPa. The outer diameter of the friction disk is 250 mm. Assume uniform wear. 15. The inner diameter of the friction disk is

A single disc clutch with both the sides effective is used to run a machine through a shaft rotating at a uniform speed of 240 rpm. The coefficient of friction is 0.25. The inner and outer diameters of the disc are 120 mm and 240 mm, respectively. Maximum intensity of pressure is 120 kNm. The moment of inertia of the rotating parts of the machine

An automotive plate clutch is used to transmit 4 kW at 600 rpm. The coefficient of friction is 0.35 and axial load on clutch is 5 kN. Inner and outer diameter are 150 mm and 220 mm, respectively. The factor of safety with respect to slippage when the clutch is brand new is

(a) 6 kg (c) 2 kg (b) 8 kg (d) 4 kg,A centrifugal clutch, transmitting 20 kW at 750 rpm consists of four shoes. The clutch is to be engaged at 75 of the running speed. The inner radius of the drum is 165 mm, while the radius to the center of gravity of the shoe, when the clutch is engaged, is 140 mm. The coefficient of friction is 0.25. The mass

In a multiplate clutch, the ratio of number of plates on driver to that on the driven shaft is 2 while their difference is 2. The number of pairs of friction surface in contact is (a) 4 (b) 2 (c) 5 (d) 6

A mass of 2000 kg is lowered at a velocity of 2 ms from a drum as shown in the figure below. Mass of the drum is 50 kg and its radius of gyration is 1 m. On applying brake, the mass is brought to rest in a distance of 0.5 m. The energy absorbed by brake is (kJ) 0 1m. 2000 kg

A brake has to stop a car within 10 m after the brakes are applied. The mass of the car is 500 kg and the car travels at 72 kmph before the brakes are applied. What is the energy to be absorbed by the brake (a) 10 kJ (c) 100 kJ (b) 158 kJ (d) 465 kJ 00

In a differential band brake shown below, the sum of the tensions and the ratio of the tensions in the steel band are 500 N and 1.5, respectively. For self locking, the ratio ab is equal to a a) 1.0 (b) 1.5 b (c) 2.0 (d) 2.5

A braking torque of 80 Nm is applied for 5 sec to bring the shaft rotating at 100 rpm to rest, The heat generated is kJ

A simple band brake is applied to a drum of 560 mm diameter which rotates at 240 r.p.m Angle of contact of the band is 270. Coefficient of friction is 0.3. The power absorbed is 40 kW. 0 140m 800m FINT (a) 62.6 mm (c) 87.4 mm AF 09. The maximum tension in the band is (a) 4792 N (b) 5218 N (c) 6210 N (d) 7502 N 10. If the thickness of band is 3mm