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) Both A and R are individually true and R is the correct explanation of A

(b) Both A and R are individually true but R is not the correct explanation of A

(c) A is true but R is false

(d) A is false but R is true

1 Answer

Answer :

(c) A is true but R is false

Related questions

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 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 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

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 : 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 : Which one of the following pair is correctly matched? [IES-2000] (a) Beauchamp tower ........................First experiments on journal bearings (b) Osborne Reynolds ........................ ... .Pivot and Collar bearings (d) Ball bearings...............................Hydrodynamic lubrication

Last Answer : (a) Beauchamp tower ........................First experiments on journal bearings

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 : 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 : 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 : 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 : 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 : 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 : Hydrostatic and hydrodynamic lubrication are the same thing. a) True b) False

Last Answer : b) False

Description : If fluid film pressure is high and surface rigidity is low than mode of lubrication is called as elastohydrodynamic lubrication. a) True b) False

Last Answer : a) True

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 : Assertion A: Marine structures are made specially bulky and strong. Reason R: Sea insects result in undermining of the hardest and the soundest building material Select your answer based on the coding system given below: (A) ... of A (C) A is true but R is false (D) A is false but R is true

Last Answer : (A) Both A and R is true and R is the correct explanation of A

Description : Starting friction is low in case of the __________ lubrication. (A) Boundary (B) Hydrodynamic (C) Hydrostatic (D) Mixed/semi-fluid

Last Answer : (C) Hydrostatic

Description : Assertion A : Normally turpentine oil is recommended as thinner for indoor painting. Reason R : Turpentine oil is costlier than other thinners. Select your answer according to the coding system given below: (A) Both A and R is ... of A (C) A is true but R is false (D) A is false but R is true

Last Answer : Answer: Option B

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 : 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 : 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 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

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 : 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 : In sliding contact bearings, a positive pressure can be built up and a load supported by a fluid only by the use of a: [IES-2005] (a) Diverging film (b) Converging-diverging film (c) Converging film (d) Flat film

Last Answer : (c) Converging film

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 : In hydrostatic bearings (A) The Oil film pressure is generated only by the rotation of the journal (B) The oil film is maintained by supplying oil under pressure (C) Do not require external supply of lubricant (D) Grease is used for lubrication

Last Answer : (B) The oil film is maintained by supplying oil under pressure

Description : Assertion(A): Per capita Income is not a useful criterion and should not be used as measure of development. Reason( R) :Kerala with lower per capita income has a better human development ranking than Haryana. a) Both A ... of A. c) A is correct but R is wrong. d) A is wrong but R is correct.

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Description : Assertion A.: The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R): If certain deposition takes place and is not removed, it obstructs free flow and causes further ... correct explanation of A C. A is true but R is false D. A is false but R is true

Last Answer : ANS: A

Description : Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other ... of A C. A is true but R is false D. A is false but R is true

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Description : Assertion A.: A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R): It helps to accommodate the scum in the septic tank. A. Both A and R is true and R is the correct ... is not a correct explanation of A C. A is true but R is false D. A is false but R is true

Last Answer : ANS: A

Description : Assertion A.: The determination of pH value of sewerage is important. Reason (R): The efficiency of certain treatment methods depends upon the availability of pH value. A. Both A and R are true and R is the ... correct explanation of A C. A is true but R is false D. A is false but R is true

Last Answer : ANS: A

Description : The following questions consists of 2 statements - Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below: (a) Both A and R are true and R is the correct explanation for A (b) ... explanation for A (c) A is true but R is false (d) A is false but R is true

Last Answer : (b) Both A and R are true and R is not the correct explanation for A

Description : Assertion (A): Maddie tried to prepare her lessons, but she could not put her mind on work. Reason (R): Maddie was missing the fun they used to have by teasing Wanda. (a) Both A and R are true and R is the correct ... A is true but R is false (d) A is false but R is true (e) Both A and R are false

Last Answer : (c) A is true but R is false

Description : Assertion (A): Wanda did not like Peggy and Maddie. Reason (R): She made fun of them by drawing their heads on her dresses for revenge. (a) Both A and R are true and R is the correct explanation of A (b) Both A ... c) A is true but R is false (d) A is false but R is true(e) Both A and R are false

Last Answer : (e) Both A and R are false

Description : Assertion (A): Peggy was not cruel. Reason (R): She protected small children from bullies. (a)Both A and R are true and R is the correct explanation of A (b)Both A and R are true but R is not the correct explanation ... )A is true but R is false (d) A is false but R is true (e)Both A and R are false

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Description : Assertion: Black soils are black in colour due to diffusion of iron in crystalline and metamorphic rocks. Reason: They develop deep cracks during hot weather Options: (a) Both A and R are true and R is the correct explanation of ... of A.(c) A is true but B is false. (d) A is false but R is true.

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Description : Assertion (A): There are several goods and services that society needs however private sector doesn t produce all of them. Reason (R): Private sector is profit driven. (a) Both A & R are true and R is the correct ... correct explanation of A. (c) A is true but R is false. (d) Both A & R are false.

Last Answer : (a) Both A & R are true and R is the correct explanation of A

Description : Assertion (A): Mohan is a shopkeeper who pays his taxes on time. He has employed two workers Raghu and Rakesh in his shop. He pays them well but none of the workers get paid leaves in a year. Reason (R): Rakesh ... correct explanation of A. (c) A is true but R is false. (d) Both A & R are false.

Last Answer : (a) Both A & R are true and R is the correct explanation of A

Description : Assertion (A): The development of agriculture and industry leads to the development of tertiary sector. Reason (R): As the agriculture and industrial sectors develop, the demand for storage, transport, banking, insurance, etc, increases ... A. (c) A is true but R is false. (d) Both A & R are false.

Last Answer : (a) Both A & R are true and R is the correct explanation of A

Description : Assertion : Rainbow is an example of the dispersion of sunlight by the water droplets. Reason: light of shorter wavelength is scattered much more than light of longer wavelength (a) Both A and R are true and R is the correct ... 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) :Sunlight reaches us without dispersion in the form of white light and not as a component. Reason(R) : Dispersion takes place due to variation of refractive index for different wavelength but in vaccum the speed of ... of 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 : Assertion (A) : Periplaneta americana is nocturnal, omnivorous, household pest. Reason (R) : It is because it acts as scavenger. (a) A is true but R is false. (b) A is false but R is true. (c) Both ... R is correct explanation of A. (d) Both A and R are true but R is not correct explanation of A

Last Answer : (d) Both A and R are true but R is not correct explanation of A.

Description : Assertion A: Large size stones are required in stone revetment in shore protection. Reason R: Resistance of stone to wave force is proportional to its volume and wave force is proportional to the exposed area of the stone. ... of A (C) A is true but R is false (D) A is false but R is true

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Description : Assertion A: For a given depth of cut, the output of a power shovel can be increased by decreasing the angle of swing. Reason R: If the angle of swing is decreased, the cycle time will be decreased. Select the ... explanation of A (C) A is true but R is false (D) A is false but R is true

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Description : Assertion A: Depth and width required at the entrance to a harbour are more than those required in the channel. Reason R: The entrance to a harbour is usually more exposed to waves as compared to the harbour itself. ... explanation of A (C) A is true but R is false (D) A is false but R is true

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