Description : Assertion (A): Hydrostatic lubrication is more advantageous when compared to hydrodynamic lubrication during starting and stopping the journal in its bearing. Reason (R): In hydrodynamic lubrication, the fluid film pressure is ... (c) A is true but R is false (d) A is false but R is true
Last Answer : (b) Both A and R are individually true but R is not 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 : The most suitable bearing for carrying very heavy loads with slow speed is (a) Hydrodynamic bearing (b) ball bearing [IAS 1994] (c) Roller bearing (d) hydrostatic bearing
Last Answer : (d) hydrostatic bearing
Description : Match List I with List II and select the : [IES-2002] List I (Bearings) List II (Load type) A. Hydrodynamic Journal bearing 1. High radial and thrust load combined B. Rectangular Hydrostatic bearing 2. Radial load only C. Taper Roller ... (a) 2 3 1 4 (b) 4 1 3 2 (c) 2 1 3 4 (d) 4 3 1 2
Last Answer : (a) 2 3 1 4
Description : Satisfactory hydrodynamic film in a journal bearing is formed when (a) Journal speed is low; unit pressure on the bearing is high and viscosity of lubricant used is low [IES-2006] ... journal speed, unit pressure on bearing and lubricant viscosity exists resulting in low coefficient of friction
Last Answer : (c) Journal speed is high; unit pressure on the bearing is high and viscosity of lubricant used is high
Description : The bearing characteristic number in a hydrodynamic bearing depends on- (a) Length, width and load (b) length, width and speed. [IES-1996] (c) Viscosity, speed and load (d) viscosity, speed and bearing pressure.
Last Answer : (d) viscosity, speed and bearing pressure.
Description : What is the main advantage of hydrodynamic bearing over roller bearing? (a) Easy to assemble [IES-2005] (b) Relatively low price (c) Superior load carrying capacity at higher speeds (d) Less frictional resistance
Last Answer : (c) Superior load carrying capacity at higher speeds
Description : A journal bearing with hydrodynamic lubrication is running steadily with a certain amount of minimum film thickness. When the load and speed are doubled, how does the minimum film thickness vary? [IES-2008 ... Gets reduced to one-fourth of original value (d) Gets reduced to half of original value
Last Answer : (a) Remains unchanged
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 : Which one of the following is correct? [IES-2008] A hydrodynamic slider bearing develops load bearing capacity mainly because of- (a) Slider velocity (b) wedge shaped oil film (c) Oil compressibility (d) oil viscosity
Last Answer : (b) wedge shaped oil film
Description : In hydrodynamic bearing, (A) The axis of journal is eccentric with respect to axis of bearing (B) The axis of journal is concentric with respect to axis of bearing (C) The axis can be either eccentric or concentric depending upon speed (D) None of the above
Last Answer : (A) The axis of journal is eccentric with respect to axis of bearing
Description : For elasto-hydrodynamic lubrication (A) There should be relative motion between the surfaces of the journal and the bearing and wedge shaped clearance space (B) There should be external source like ... be elastic deformation of the parts in contact (D) There should be metal to metal contact
Last Answer : (C) There should be elastic deformation of the parts in contact
Description : For hydrodynamic lubrication (A) There should be relative motion between the surfaces of the journal and the bearing and wedge shaped clearance space (B) There should be external source like pump to ... be elastic deformation of the parts in contact (D) There should be metal to metal contact
Last Answer : (A) There should be relative motion between the surfaces of the journal and the bearing and wedge shaped clearance space
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 : Sommerfeld number is (A) Similar to bearing characteristic number (B) Similar to Reynold’s number (C) Dimensionless parameter that contains all the design parameters (D) Used to find out dynamic load carrying capacity of the hydrodynamic bearing
Last Answer : (C) Dimensionless parameter that contains all the design parameters
Description : Boundary lubricated bearing is (A) Thick film bearing (B) Thin film bearing (C) Hydrodynamic bearing (D) Hydrostatic bearing
Last Answer : (B) Thin film bearing
Description : If we exclude the cost factor, which bearing is preferred? a) Hydrostatic b) Hydrodynamic c) Both are equally preferred d) Cannot be determined
Last Answer : a) Hydrostatic
Description : A journal bearing is a ______ contact bearing working on the hydrodynamic lubrication and which supports load in____ direction. a) Sliding, Axial b) Rolling, Radial c) Sliding, Radial d) Rolling, Axial
Last Answer : c) Sliding, Radial
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): Oil as a cutting fluid result in a lower coefficient of friction. Reason (R): Oil forms a thin liquid film between the tool face and chip, and it provides 'hydrodynamic lubrication'. [IES- 2000] (a ... explanation of A (c) A is true but R is false (d) A is false but R is true
Last Answer : (c) A is true but R is 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 : Hydrostatic and hydrodynamic lubrication are the same thing. a) True b) False
Last Answer : b) False
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 : 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 : 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 : 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 : In hydrodynamic lubrication, film thickness remains unaffected by change in speeds. a) True b) Increase with increase in speed c) Decrease with increase in speed d) Disappear as the speed tends to infinty
Last Answer : b) Increase with increase in speed
Description : For two spring connected in series, the force acting on each spring is same and equal to half of the external force. a) True 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
Last Answer : (b) False
Description : The life of an individual ball bearing is the time period for which it works without any signs of failures. (a) True (b) False
Description : Stribeck equation gives the dynamic load capacity of the bearing. (a) True (b) False
Description : Needles bearing consist of rollers of small diameter and very small length. (a) True (b) False
Description : A cylinder roller creates lesser noise than a deep groove ball bearing. (a) True (b) False
Description : Angular contact bearing can take thrust as well as radial loads. (a) True (b) False
Last Answer : (a) True
Description : Cylindrical roller bearing has a lower load capacity as compared to deep groove ball bearing. (a) True (b) False
Description : Assertion (A): In equilibrium position, the journal inside a journal bearing remains floating on the oil film. [IES-1995] Reason (R): In a journal bearing, the load on the bearing is perpendicular to the axis of the ... explanation of A (c) A is true but R is false (d) A is false but R is true
Description : Needles bearing consist of rollers of small diameter and very small length. a) True 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 : The life of an individual ball bearing is the time period for which it works without any signs of failures. a) True b) False
Description : Stribeck equation gives dynamic load capacity of the bearing. a) True b) False
Description : Cylinder roller creates lesser noise than deep groove ball bearing. a) True b) False
Description : Angular contact bearing can take thrust as well as radial loads. a) True b) False
Last Answer : a) True
Description : Cylindrical load bearing has lower load capacity as compared to deep groove ball bearing. a) True b) False
Description : A radial bearing supports the load that acts along the axis of the shaft. a) True b) False
Description : Which one of the following bearing is intended for a very heavy radial load? (a) Ball bearing (b) Self-aligning roller bearing (c) Roller bearing (d) Thrust bearing
Last Answer : (b) Self-aligning roller bearing
Description : Match List-I (Type of Anti-friction bearing) with List-II (Specific Use) and select the using the code given below the Lists: [IES-2006] List-I List -II A. Self-aligning ball bearing 1. For pure axial load B. Taper roller bearing 2. For ... C D (a) 2 1 3 4 (b) 3 4 2 1 (c) 2 4 3 1 (d) 3 1 2 4
Last Answer : (c) 2 4 3 1
Description : Antifriction bearings are (a) sleeve bearings (b) hydrodynamic bearings (c) thin lubricated bearings (d) none of the mentioned
Last Answer : (d) none of the mentioned
Description : Antifriction bearings are A. Sleeve bearings B. Hydrodynamic bearings C. Thin lubricated bearings D. None of the above
Last Answer : D. None of the above
Description : Which one of the following types of bearings is employed in shafts of gearboxes of automobiles? [IES-1999] (a) Hydrodynamic journal bearings (b) Multi-lobed journal bearings (c) Antifriction bearings (d) Hybrid journal bearings
Last Answer : (c) Antifriction bearings