Description : A clearance bearing is design accurately to keep the radius of journal and bearing equal. a) Journal radius is kept larger b) Journal radius is kept smaller c) True d) Can’t be determined
Last Answer : b) Journal radius is kept smaller
Description : A thick film bearing is a bearing (A) Where the surfaces of journal and the bearing are completely separated by a film of lubricant (B) Where the surfaces of journal and the bearing are partially ... are separated by a film created by elastic deflection of parts (D) Where there is no lubricant
Last Answer : (A) Where the surfaces of journal and the bearing are completely separated by a film of lubricant
Description : A thin film bearing is a bearing (A) Where the surfaces of journal and the bearing are completely separated by a film of lubricant (B) Where the surfaces of journal and the bearing are partially ... are separated by a film created by elastic deflection of parts (D) Where there is no lubricant
Last Answer : (B) Where the surfaces of journal and the bearing are partially separated by a film of lubricant and there is partial metal to metal contact
Description : A zero film bearing is a bearing (A) Where the surfaces of journal and the bearing are separated by a thick film of lubricant (B) Where the surfaces of journal and the bearing are partially ... bearing are separated by a film created by elastic deflection of parts (D) Where there is no lubricant
Last Answer : (D) Where there is no lubricant
Description : In case of partial bearing, the angle of contact of the bushing with the journal is (A) 270° (B) More than 180° (C) Less than 180° (D) 360°
Last Answer : (C) Less than 180°
Description : Petroff’s equation is used to find out (A) Load carrying capacity of the bearing (B) Frictional losses in the bearing (C) Unit bearing pressure on the bearing (D) Pressure distribution around the periphery of the journal
Last Answer : (B) Frictional losses in the bearing
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 : In case of partial bearing, the angle of contact of the bushing with the journal is usually (A) 120° (B) 180° (C) 45° (D) 360°
Last Answer : (A) 120°
Description : In an oil-lubricated journal bearing, coefficient of friction between the journal and the bearing. [IES-1995] (a) Remains constant at all speeds. (b) is minimum at zero speed and increases ... speed. (d) becomes minimum at an optimum speed and then increases with further increase in speed.
Last Answer : (d) becomes minimum at an optimum speed and then increases with further increase in speed.
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 : 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 : 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 : Fitted bearing must be partial bearing. a) True b) No c) No lubricating space is required d) Can’t be stated
Last Answer : a) True
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 : 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 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 : 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 : 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 : In a journal bearings, the radius of the friction circle increases with the increase in- [IES-1997] (a) Load (b) Radius of the journal (c) Speed of the journal (d) Viscosity of the lubricant
Last Answer : (b) Radius of the journal
Description : Which of the following is an antifriction bearing? (a) journal bearing (b) collar bearing (c) needle bearing (d) pivot bearing
Last Answer : (c) needle bearing
Description : Match List -I (Bearings) with List-II (Applications) and select the using the codes given below the lists: [IAS-1998] List -I List-II A. Journal bearing 1. Electric motors B. Thrust bearing 2. Watches C. Conical pivot bearing 3. Marine ... D (a) 3 4 1 2 (b) 4 2 1 3 (c) 3 4 2 1 (d) 4 2 3 1
Last Answer : (c) 3 4 2 1
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 : 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 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 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 : The property of the bearing material to yield and adopt its shape to that of journal is called (A) Embeddability (B) Conformability (C) Viscosity (D) Endurance limit stress
Last Answer : (B) Conformability
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 hydrostatic 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 : (B) There should be external source like pump to supply lubricant under pressure
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 hydrostatic 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 : (B) The axis of journal is concentric with respect to axis of bearing
Description : In case of full journal bearing, the angle of contact of the bushing with the journal is (A) 60° (B) 90° (C) 180° (D) 360°
Last Answer : (D) 360°
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 : If μ = absolute viscosity, N= speed of the journal and p = unit bearing pressure, then the bearing characteristic number is given by (A) μN/p (B) μp/N (C) pN/μ (D) μ/pN
Last Answer : (A) μN/p
Description : Oil in journal bearing should be applied at the point where load is (A) Nil or lightest (B) Maximum (C) Average (D) Any one of the above
Last Answer : (A) Nil or lightest
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 : 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 : Efficiency of the screw _______ with increase of coefficient of friction. a) decreases b) increases c) has no effect d) cannot be determined
Last Answer : a) decreases
Description : Temperature rise in partial bearing is ____ than full bearing. a) Lesser b) Greater c) Equal
Last Answer : a) Lesser
Description : Which of the following bearing is preferred for oscillating conditions? (a) Double row roller bearing (b) Taper roller bearing (c) Needle roller bearing (d) Angular contact single row ball bearing
Last Answer : (c) Needle roller bearing
Description : When comes down to stress reduction, which one is preferred? a) Solid flywheel b) Split flywheel c) Both have equal stresses d) Cannot be determined
Last Answer : b) Split flywheel
Description : The purpose of lubrication in an antifriction bearing is (a) to reduce the friction between balls and races (b) dissipation of frictional heat prevention of corrosion (c) protection of the bearing from dirt and other foreign particles (d) all of the mentioned
Last Answer : (d) all of the mentioned
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 : 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 : Babbitt metal used for making bearings should have (A) High co-efficient of friction between journal and bearing (B) Ability to retain lubricant on its surface (C) Low co-efficient of friction between journal and bearing (D) Both (B) & (C)
Last Answer : (A) High co-efficient of friction between journal and bearing
Description : There is a problem of alignment in deep groove ball bearings. (a) Yes (b) No, it is self-aligning (c) It aligns itself only in some particular cases (d) Can’t be determined
Last Answer : (a) Yes
Description : There is problem of alignment in deep groove ball bearings. a) Yes b) No, it is self-aligning c) It aligns itself only in some particular cases d) Can’t be determined
Last Answer : a) Yes
Description : Spiral spring is quite rigid. a) Yes b) No it is flexible c) It is of moderate rigidity d) Rigidity can’t be determined
Last Answer : b) No it is flexible
Description : Set screws are subjected to tensile forces only. a) Yes b) No, they are subjected to compressive forces only c) Both compressive and tensile d) Can’t be determined
Last Answer : b) No, they are subjected to compressive forces only