Description : The static load is defined as the load acting on the bearing when the shaft is _____. (a) stationary (b) rotating at rpm
Last Answer : (a) stationary
Description : Calculate the bearing life if expected life for 90% bearings is 9000 hr and the shaft is rotating at 1500 rpm. (a) 850 million rev (b) 810 million rev (c) 810 hr (d) 850 hr
Last Answer : (b) 810 million rev
Description : A full journal bearing having clearance to radius ratio of 1/100, using a lubricant with μ=28×10-3 Pa s supports the shaft journal running at N = 2400 rpm If bearing pressure is 1.4 MPa, the Somerfield number is [IES-2001] (a) 8×10-3 (b) 8×10-5 (c) 0.48 (d) 0.48×10
Last Answer : (a) S = (μN s /p) (r/c) 2
Description : Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) None of the listed
Last Answer : c) Moving or stationary
Description : A_______ bearing supports the load acting along the axis of the shaft. a) Thrust b) Radial c) Longitudinal d) Transversal
Last Answer : a) Thrust
Description : ______ is used for a shaft that supports rotating elements like wheels, drums or rope sleaves. a) Spindle b) Axle c) Shaf d) None of the listed
Last Answer : a) Spindle
Description : Which one of the following parts of a ball bearing is mounted on the rotating shafts and tends to rotate the shaft? (a) Inner race (b) Outer race (c) Rolling element (d) Cage
Last Answer : (a) Inner race
Description : Assertion (A): In steady rotating condition the journal inside a hydrodynamic journal bearing remains floating on the oil film. [IES-2008] Reason (R): The hydrodynamic pressure developed in steady rotating conditions in journal ... A (c) A is true but R is false (d) A is false but R is true
Last Answer : (a) Both A and R are true and R is the correct explanation of A
Description : Woodruff key permits _____ movement b/w shaft and the hub. a) Axial b) Radial c) Eccentric d) None of the listed
Last Answer : b) Radial
Description : Footstep bearing is an axial load bearing. a) True b) Thrust load c) Shear load d) None of the listed
Last Answer : b) Thrust load
Description : Which of the following cannot take radial load? a) Cylindrical Roller bearing b) Taper roller bearing c) Thrust ball bearing d) None of the listed
Last Answer : c) Thrust ball bearing
Description : A total permanent deformation of 0.0001 of the ball diameter is taken for considering static load capacity of the shaft. a) True b) False
Last Answer : a) True
Description : The ball bearing is subjected to a radial load of 4000 N. Expected life for 90% bearings is 9000 hr and the shaft is rot (a) 42.21 kN (b) 37.29 kN (c) 26.33 kN (d) 35.22 kN
Last Answer : (b) 37.29 kN
Description : Which of the following are not true for petroff’s equation? a) Shaft is considered concentric with the bearing b) Bearing is subjected to light load c) Is used to find coefficient of friction d) Frictional torque is given by fpr2l
Last Answer : d) Frictional torque is given by fpr2l
Description : A radial bearing supports the load that acts along the axis of the shaft. a) True b) False
Last Answer : b) False
Description : Load acting on bearing in its plane of rotation is called as a... A. Radial load B. Axial load C. Perpendicular load D. Thrust load
Last Answer : A. Radial load
Description : The endurance or fatigue limit is defined as the maximum value of the stress which a polished standard specimen can withstand without failure, for infinite number of cycles, when subjected to (a) static load (b) dynamic load (c) static as well as dynamic load (d) completely reversed load
Last Answer : (d) completely reversed load
Description : The dynamic load-carrying capacity of a bearing is defined as the radial load in radial bearings that can be carried for a minimum life of 1000 revolutions. (a) True (b) False
Last Answer : (b) False
Description : The dynamic load carrying capacity of a bearing is defined as the radial load in radial bearings that can be carried for a minimum life of 1000 revolutions. a) True b) False
Description : A sliding contact bearing is operating under stable condition. The pressure developed in oil film is p when the journal rotates at N rpm. The dynamic viscosity of lubricant is μ and effective coefficient of ... to p and f) (d) f is directly proportional to μ and inversely proportional to N
Last Answer : (b) f is directly proportional to μ and N
Description : Shaft is rotating machine element. A. True B. False
Last Answer : A. True
Description : Which one of the following parts of a ball bearing is mounted to the housing and is stationary? (a) Inner race (b) Outer race (c) Rolling element (d) Cage
Last Answer : (b) Outer race
Description : Consider the following statements: [IES 2007] For a journal rotating in a bearing under film lubrication conditions, the frictional resistance is- 1. Proportional to the area of contact 2. Proportional to the viscosity of lubricant 3. ... 4 (b) 1 and 4 only (c) 2, 3 and 4 only (d) 2 and 3 only
Last Answer : (a) 1, 2, 3 and 4
Description : _____ is a surface fatigue failure which occurs when the load on the bearing part exceeds the surface endurance strength of the material. (a) Scoring (b) Pitting (c) Corrosion
Last Answer : (b) Pitting
Description : Calculate the shaft diameter on rigidity basis if torsional moment is 196000N-mm, length of shaft is 1000mm. Permissible angle of twist per meter is 0.5’ and take G=79300N/mm2. a) None of the listed b) 41.2mm c) 35.8mm d) 38.8mm
Last Answer : b) 41.2mm
Description : In a slider crank mechanism, the crank is rotating at 200 rpm. If length of connecting rod is 8 mts and crank shaft is 2 mts, velocity of crosshead at 30? rotation of crank shaft equals. a.30.2 m/s b.33.2 m/s c.35.8 mts/s d.107 dynes e.25.5 m/s
Last Answer : e. 25.5 m/s
Description : Which of the following are functions of bearings? a) Ensure free rotation of shaft with minimum friction b) Holding shaft in a correct position c) Transmit the force of the shaft to the frame d) All of the listed
Last Answer : d) All of the listed
Description : If a circular shaft is welded to the plate by means of circumferential fillet, then the shaft is subjected to torsional moment M. If throat of weld is t, then torsional shear stress is given by a) M/2πtr2 b) M/πtr2 c) M/4πtr2 d) None of the listed
Last Answer : a) M/2πtr2
Description : If 8 bolts are emplaced in a clamp coupling with shaft diameter 80mm d, calculate the tensile force on each bolt if coefficient of friction is 0.3 and torque transmitted is 4000N-m. a) 51234.4N b) 45968.3N c) 41666.7N d) None of the listed
Last Answer : c) 41666.7N
Description : A muff coupling is connecting two shafts. The torque involved is 650N-m. The shaft diameter is 45mm with length and height of the key being 14mm and 80mm respectively. Find the compressive stress induced in the key. a) 70.1 N/mm2 b) 51.6N/mm2 c) 45.5N/mm2 d) None of the listed
Last Answer : b) 51.6N/mm2
Description : A muff coupling is connecting two shafts. The torque involved is 650N-m. The shaft diameter is 45mm with length and breadth of the key being 14mm and 80mm respectively. Find the shear stress induced in the key. a) 30.2N/mm2 b) 25.8N/mm2 c) 34.4N/mm2 d) None of the listed
Last Answer : b) 25.8N/mm2
Description : When the shaft is subjected to pure torsional moment, the torsional stress is given by? a) None of the listed b) 32M/πdɜ c) 16M/πdɜ d) 8M/πdɜ
Last Answer : c) 16M/πdɜ
Description : When the shaft is subjected to pure bending moment, the bending stress is given by? a) None of the listed b) 32M/πdɜ c) 16M/πdɜ d) 8M/πdɜ
Last Answer : b) 32M/πdɜ
Description : Calculate the force acting on the each pin in flexible coupling if torque transmitted is 397N-m and PCD=120mm with number of pins 6. a) 1400.3N b) 1102.8N c) 1320.3N d) None of the listed
Last Answer : b) 1102.8N
Description : A force 2P is acting on the double transverse fillet weld. Leg of weld is h and length l. Determine the shear stress in a plane inclined at θ with horizontal. a) PSinθ(Sinθ+Cosθ)/hl b) P(Sinθ+Cosθ)/hl c) Pcosθ(Sinθ+Cosθ)/hl d) None of the listed
Last Answer : a) PSinθ(Sinθ+Cosθ)/hl
Description : An antifriction bearing consists of (a) rolling elements (b) races (c) cages (d) all of the listed
Last Answer : (d) all of the listed
Description : Which of the following cannot tolerate misalignment? (a) Angular contact bearing (b) Cylinder roller bearing (c) Thrust ball bearings (d) All of the listed
Last Answer : (d) All of the listed
Description : The listed life of a rolling bearing, in a catalog is the, (a) minimum expected life (b) maximum expected life (c) average life (d) none of the mentioned
Last Answer : (a) minimum expected life
Description : Which of the following cannot tolerate misalignment? a) Angular contact bearing b) Cylinder roller bearing c) Thrust ball bearings d) All of the listed
Description : Consider the following pairs of types of bearings and applications: 1. Partial Journal bearing................... Rail wagon axles 2. Full journal bearing ......................Diesel engine crank-shaft 3. Radial bearing ... matched? [IES-2000] (a) 1 alone (b) 1 and 2 (c) 2 and 3 (d) 1, 2 and 3
Last Answer : (b) 1 and 2
Description : Which one of the following sets of parameters should be monitored for determining safe operation of journal bearing? [IES-2000] Oil pressure, bearing metal temperature and bearing vibration (b) ... shaft (c) Bearing metal temperature and oil pressure (d) Oil pressure and bearing vibration
Last Answer : Oil pressure, bearing metal temperature and bearing vibration
Description : Consider tile following statements: [IES-1993; 2002; 2006] Radius of friction circle for a journal bearing depends upon 1. Coefficient of friction 2. Radius of the journal 3. Angular speed of rotation of the shaft Which of the ... ) 1,2 and 3 (b) Only 1 and 2 (c) Only 2 and 3 (d) Only 1 and 3
Last Answer : (b) Only 1 and 2
Description : Increase in values of which of the following results in an increase of the coefficient of friction in a hydrodynamic bearing? [IES 2007] 1. Viscosity of the oil. 2. Clearance between shaft and bearing. 3. Shaft speed. Select the ... 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3
Last Answer : (b) 1 and 3 only