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 : 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 : 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 : Static load is defined as the load acting on the bearing when shaft is _____ a) Stationary b) Rotating at rpm
Last Answer : a) Stationary
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 : Assertion (A): In hydrodynamic journal bearings, the rotating journal is held in floating condition by the hydrodynamic pressure developed in the lubricant. Reason (R): Lubricant flows in a converging-diverging channel. [IES-1994] ... 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 individually true and R is the correct explanation of A
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 : Cotter joints is used for transforming rotating torque. A. True B. False
Last Answer : B. False
Description : A knuckle joint is unsuitable for two rotating shafts, which transmit torque a) True b) False
Last Answer : a) True
Description : A coupling is a mechanical device that temporarily joins two rotating shafts to each other. a) True b) False
Last Answer : b) False
Description : Assertion (A): In anti-friction bearings, the frictional resistance is very low as the shaft held by it remains in floating condition by the hydrodynamic pressure developed by the lubricant. [IES-2006] Reason (R): In hydrodynamic ... of A (c) A is true but R is false (d) A is false but R is true
Last Answer : (d) A is false but R is true
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
Description : A radial bearing supports the load that acts along the axis of the shaft. a) True b) False
Description : The hub is treated as a solid shaft while calculating torsional shear stress in the hub. a) True b) False
Description : Solid shaft is costlier than hollow shaft of same weight. a) True b) False
Description : The strength of hollow shaft is more than the strength of solid shaft of same weight. a) True b) False
Description : The stiffness of solid shaft is more than the stiffness of hollow shaft with same weight. a) True b) False
Description : Hot rolling produces a stronger shaft then cold rolling. a) True b) False
Description : Counter shaft is a secondary shaft. a) True b) False
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 : When the torque required by the machine is more than the torque supplied by the motor, the flywheel is (A) Accelerated (B) Retarded (C) Rotating with constant speed (D) Any of the above
Last Answer : (B) Retarded
Description : A machine started malfunctioning due to some issues with the coupling. The coupling emplaced in the machine was Oldham. The only coupling available in the workshop is Hooke’s coupling. So Oldham coupling can be replaced by Hooke’s coupling. a) True b) False
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 : 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 : A bushed-pin type flange coupling is used (A) For intersecting shafts (B) When the shafts are not in exact alignment (C) For small shafts rotating at slow speeds (D) For parallel shafts
Last Answer : (B) When the shafts are not in exact alignment
Description : A spring is defined as a(an) ___ machine element. (A) plastic (B) elastic (C) special purpose (D) none of the above
Last Answer : (B) elastic
Description : In vehicle flywheel is place between 1. clutch and propeller shaft 2. engine and clutch 3. before engine 4. propeller shaft and differential
Last Answer : 2. engine and clutch
Description : The hub diameter of the flywheel is taken as 1. 2.5(shaft diameter) 2. 1.5(shaft diameter) 3. 4(shaft diameter) 4. 2(shaft diameter)
Last Answer : 4. 2(shaft diameter)
Description : In vehicles, flywheel is placed in between (A) Engine and clutch (B) Clutch and Propeller shaft (C) Propeller shaft and Differential (D) Before engine
Last Answer : (A) Engine and clutch
Description : The hub diameter of the flywheel is taken as, (A) 2.5 (shaft diameter) (B) 1.5 (shaft diameter) (C) 4 (shaft diameter) (D) 2 (shaft diameter)
Last Answer : (D) 2 (shaft diameter)
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 : The rolling contact bearings as compared to sliding contact bearings have (a) small overall dimensions (b) accuracy of shaft alignment (c) low starting and low running friction except at very high speeds (d) all the mentioned
Last Answer : (d) all the mentioned
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 : 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 : 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
Description : In hydrodynamic bearing, when the shaft begins to rotate in clockwise direction, (A) The journal climbs to the right side of the bearing without metal to metal contact (B) The journal climbs to the left ... sinks down to the bottom of the bearing (D) The journal is at the center of the bearing
Last Answer : (A) The journal climbs to the right side of the bearing without metal to metal contact
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