Below are 75 most important Tribology mcq with answers for exams. Tribology (Mechanical Engineering) multiple choice questions are provided with the answer key down every questions. That make easy to study Tribology mcq. We are planning to provide tribology mcq pdf for download along with these mcqs.
Tribology mcq with answers
Q.1-The following is (are) the example(s) of static friction
A : Shoe brake applied to a vehicle
B : Shoe brake applied to a train
C : Dry grinding stone abrades the surface of metal
D : All of the above
All of the above
Q.2-As per laws of dry friction, the frictional force
A : depends upon the nature of sliding surface
B : is independent of the sliding velocity
C : is directly proportional to the load
D : All of the above
All of the above
Q.3-Lubricant converts
A : Solid friction into liquid friction
B : Liquid friction into solid friction
C : both ‘a’ and ‘b’
D : None of the above
Solid friction into liquid friction
Q.4-The following is not a type of sliding contact bearing
A : Ball bearing
B : Journal bearing
C : Bush bearing
D : Thrust bearing
Ball bearing
Q.5- The following is not a type of roller contact bearing
A : Ball bearing
B : Journal bearing
C : Roller bearing
D : All of the above
Journal bearing
Q. 6-In thrust bearings, the load acts
A : perpendicular to the axis of shaft
B : in axial direction
C : both ‘a’ and ‘b’
D : None of the above
in axial direction
Q. 7-Boundary friction conditions may develop in journal bearings, when shaft passes through zero speed during
A : starting
B : stopping
C : reversing
D : All of the above
All of the above
Q.8-The following lubricants are obtained by fractional distillation of petroleum
A : Mineral oils
B : Fatty oils
C : Solid lubricants
D : All of the above
Mineral oils
Q.9-For low pressure and low speeds, we use
A : Mineral oils
B : Semi-solid lubricants
C : Solid lubricants
D : All of the above
Solid lubricants
Q. 10-The pour point test is employed to indicate the suitability of oil for ____ temperature operations.
A : low
B : high
C : both ‘a’ and ‘b’
D : None of the above
low
Q.11-The flash point of lubricant must be _______ the working temperature.
A : well below
B : well above
C : equal to
D : None of the above
well above
Q.12-Specific gravity of lubricant can be measured by using
A : Hydrometer
B : Viscometer
C : Anemometer
D : Pyranometer
Hydrometer
Q.13-API number of water is
A : 1
B : 5
C : 10
D : 20
10
Q. 14-The colour code for various grades of lubricants is as follows
Grade of lubricant Colour code
A : Spindle oil 1. Red
B : Heavy-medium 2. Orange
C : Heavy/Extra heavy 3. Brown
D : Grease 4. Yellow
The correct order is
A : a-3, b-1, c-2, d-4
B : a-4, b-3, c-1, d-2
C : a-1, b-2, c-3, d-4
D : a-4, b-3, c-2, d-1
a-4, b-3, c-1, d-2
Q.15-The bi-weekly lubrication is indicated by
A : rectangle
B : triangle
C : circle
D : hexagon
circle
Q.16-The monthly lubrication is indicated by
A : rectangle
B : triangle
C : circle
D : hexagon
rectangle
Q.17-Lubrication Oil from automobile machines come under ____ oil.
A : Clean oil
B : Less dirty
C : More dirty
D : Highly dirty
Highly dirty
Q.18-The six monthly lubrication is indicated by
A : rectangle
B : triangle
C : circle
D : hexagon
hexagon
Q. 19- In which period was the word tribology coined after realizing significant losses due to lack of knowledge of friction and wear and a need for an interdisciplinary approach was considered?
A : 1960
B : 1966
C : 1964
D : 1970
1966
20- Out of the following disciplines which one is not considered for an interdisciplinary approach in tribology?
A : Solid and Fluid mechanics.
B : Chemistry.
C : Material Science.
D : Industrial Engineering.
Industrial Engineering.
Q.21- The meaning of the Greek word “Tribos” from which the word Tribology is formed is
A : Rubbing.
B : Movement.
C : FluiD :
D : Heat.
Rubbing.
Q.22 – Which one of the following is NOT the purpose of Tribology?
A : Improve service life.
B : Increase safety and reliability.
C : Reduce fatigue.
D : Increase heat generation.
Increase heat generation.
Q.23 – Asperities are basically
A : Sharp tips on surface.
B : Edge of a surface.
C : Corner of a surface.
D : Hole in a surface.
Sharp tips on surface.
Q.24 – Which one is not a standard method for quantifying surface roughness?
A : Root mean square roughness.
B : Average roughness.
C : Flatness tolerance(GD&T).
D : Rating method on any arbitrary scale.
Rating method on any arbitrary scale.
Q.25 – Which one of the following statement is true?
A : Wear rate increases with increasing loaD :
B : Wear rate decreases with increasing temperature.
C : Wear rate decreases with increasing speeD :
D : Wear rate is independent of load/temperature.
Wear rate increases with increasing loaD :
Q.26 – The purpose of lubricant filter system is
A : To remove the debris from the lubricant.
B : To enhance the viscosity of lubricant.
C : Reduce the temperature of lubricant.
D : Reduce the quantity of lubricant.
To remove the debris from the lubricant.
Q.27 – Which one of the following parameter is not included by Stribeck curve?
A : Viscosity of the lubricant.
B : Speed of the surfaces.
C : Load at the interface.
D : Surface roughness.
Surface roughness.
Q.28 – Which one of the following statements is NOT true about friction?
A : Friction is tangential resistance to motion.
B : Friction is dependent upon the surface of the content.
C : Friction is greater on rough surface.
D : Friction does not decrease with lubrication.
Friction does not decrease with lubrication.
Q.29 – Coefficient of friction is independent of
A : Temperature.
B : Surface Roughness.
C : Hardness.
D : Surface area of contact.
Surface area of contact.
Q.30 – Phenomenon of stick-slip occurs because of
A : Large difference between static and kinetic coefficients of friction.
B : Additional force requirement to move the object.
C : Increase in hardness of surfaces.
D : Lubrication is applied on the surfaces.
Large difference between static and kinetic coefficients of friction.
Q.31 – Adhesion component of dry friction is negligible at interface of
A : High temperature surfaces.
B : Lubricated tribo pair.
C : Rough surfaces.
D : Extra smooth surfaces.
Lubricated tribo pair.
Q.32 – Cold weld between two surfaces happens because of
A : Excessive lubrication.
B : Adhesion between two surfaces.
C : Relatively high surface roughness.
D : Low temp on area of contact.
Adhesion between two surfaces.
Q.33 – As per the ploughing theory of friction, which of the following statements is not true?
A : Slope of asperities govern the friction force.
B : Sharp asperities causes more friction compared to round or spherical asperities.
C : Asperities on one surface interact with the asperities or valleys on the other surface.
D : An asperity of softer surface causes ploughing on the harder surface.
An asperity of softer surface causes ploughing on the harder surface.
Q.34 – The formation of junction growth can be reduced by
A : Lubrication of the surfaces.
B : Increasing the surface finish of the rubbing surfaces.
C : Annealing the surfaces.
D : All of above.
Lubrication of the surfaces.
Q.35 – Deformation of asperities causes
A : Increase in friction.
B : Decrease in friction.
C : Can increase or decrease friction.
D : No effect.
Can increase or decrease friction.
Q.36 – Ploughing effect causes
A : Piercing and penetration of the soft surface by the asperities of the hard surface.
B : Increasing in friction.
C : Both (a) & (b).
D : None of these.
Both (a) & (b).
Q.37 – Coefficient of friction due to rolling is generally
A : Greater than coefficient of sliding friction.
B : Lesser than coefficient of sliding friction.
C : Equal to sliding friction.
D : May be greater or smaller compared to sliding friction.
May be greater or smaller compared to sliding friction.
Q.38 – Which of the following are the major contributors to rolling friction?
A : Micro-slip effect within the contact areA :
B : Elastic hysteresis of the contacting materials.
C : Plastic deformation of the materials& adhesion effects in the contact.
D : All of the above.
All of the above.
Q.39 – Which one of the following is truefor ball bearings?
I. Sliding occurs between cage and balls.
II. Lubricants such as grease are used to reduce friction within ball bearing.
III. Cages are meant to bear the loaD :
A : Both (I) and (II).
B : Both (I) and (III).
C : Both (II) and (III).
D : All three (I), (II) and (III).
Both (I) and (II).
Q.40 – If an automobile tire is not filled up to the optimum pressure level it means:
A : There would be less hysteresis loss.
B : Rolling friction would be lower.
C : More steering controllability.
D : None of these.
More steering controllability.
Q. 41 – To avoid the phenomenon of stick slip due to friction instability which of the following is the right approach?
A : Increase the operation speeD :
B : Decrease the operation speeD :
C : Operation speed does not have any effect on the stick slip process.
D : Increase the difference between static and kinetic coefficient of friction.
Increase the operation speeD :
Q.42 – In a mechanical system, negative damping due to friction instability causes
A : Increase in vibration amplitude over a period of time.
B : Decrease in vibration amplitude over a period of time.
C : Amplitude remains unchanged with time.
D : None of these.
Increase in vibration amplitude over a period of time.
Q.43- Zero wear increases performance because
A : It causes polishing of surface.
B : Size of surface asperities increases.
C : It removes lubrication from the surface.
D : It increases load bearing capacity of the surface.
It causes polishing of surface.
Q.44 – Which of the following is NOT true about measurable wear?
A : Measurable wear is undesirable.
B : It can cause vibration and noise.
C : Measurable wear may roughen the surfaces.
D : It polishes the surfaces.
It polishes the surfaces.
Q.45- Which of the following is NOT true about pitting on the gear surface?
A : It is a surface fatigue failure.
B : It occurs due to repeated loading of the tooth surface.
C : It occurs because contact stress exceeds than the surface fatigue strength of the material.
D : It occurs because contact stress exceeds the compressive strength of material.
It occurs because contact stress exceeds the compressive strength of material.
Q.46- With increase in bearing clearance the load capacity of the bearing
A : Increases.
B : Decreases.
C : Does not change.
D : First decreases and then increases.
Decreases.
Q.47- Which among the following is not an adhesive wear mechanism?
A : Galling
B : Scoring.
C : Scuffing.
D : Polishing.
Polishing.
Q. 48- To minimize the sliding friction, shear strength of the lubricant compared to the shear strength of the tribo-surfaces should be:
A : Higher.
B : Lower.
C : Insignificant.
D : Equal.
Insignificant.
Q.49- As per Archard’s wear equation, wear volume in adhesive wear is independent of
A : Sliding distance of travel.
B : LoaD :
C : Hardness of the soft material.
D : Rolling distance.
Rolling distance.
Q.50- Seizure refers to
A : Binding and fastening together of the material.
B : Cracking on the surface.
C : Significant wear on the surface.
D : Significant plastic deformation.
Binding and fastening together of the material.
Q.51- Causes of seizure are
A : Poor heat dissipation.
B : Poor lubrication.
C : Smaller clearances.
D : All of above.
All of above.
Q.52- The thickness of the oxide layer formed on the surface is dependent upon
A : Rate of rupture of the oxide layer.
B : Time available to re-oxidise.
C : Rate of formation of oxide layer.
D : All of the above.
All of the above.
Q.53- Scratching is a form of
A : Abrasive wear.
B : Adhesive wear.
C : Corrosive wear.
D : Fatigue wear.
Abrasive wear.
Q.54- Wear rate is lesser in 3-body abrasion as compared to 2-body abrasion because
A : Energy is consumed in rolling motion of free hard particles.
B : Only spherical asperities are involved in 3-body abrasion.
C : Size of the asperities is smaller in 3-body abrasion.
D : Generally hardness of free particles is very low.
Energy is consumed in rolling motion of free hard particles.
Q.55- The property of MR fluid is
A : Viscosity thickening due to magnetic attraction among particles.
B : Viscosity thinning due to relative sliding.
C : Reduction in viscosity due to increase in temperature.
D : All of above.
All of above.
Q. 56- Which of the following represents correct sequence of corrosive wear?
i. Mechanical sliding at interface.
ii. Chemical reaction and formation of a reaction product (oxide, chloride).
iii. Wearing away of reaction product film.
A : (ii),(i),(iii)
B : (ii), (iii), (i)
C : (i), (iii), (ii)
D : (i), (ii), (iii)
(ii),(i),(iii)
Q.57- Erosive wear is a function of
A : Particle velocity.
B : Impact angle.
C : Size of abrasive.
D : All of above.
All of above.
Q.58 – The purpose of lubrication is
A : To reduce friction.
B : To reduce wear.
C : Transfer heat produceD :
D : All of above.
All of above.
Q.59 – Which of the following is NOT a function of lubricant in IC engine?
A : Form a film to separate the surfaces.
B : Adhere to surface.
C : Withstand high temperature inside the cylinder.
D : Reduce the size of the asperities and improve the surface finish.
Reduce the size of the asperities and improve the surface finish.
Q.60 – Synovial fluid is a lubricant that is found in
A : Human bone joints.
B : Gearboxes.
C : IC engines.
D : Rolling element bearings.
Human bone joints.
Q.61 – Which one of them is a correct combination?
1. Boundary lubrication.
2. Hydrodynamic lubrication.
3. Mixed lubrication.
4. Elastohydrodynamic lubrication.
(i) Dimensionless film thickness < 1.
(ii) Dimensionless film thickness lies between 1 and 3.
(iii) Dimensionless film thickness lies between 3 & 5.
(iv) Dimensionless film thickness is greater than 5.
A : 1-(i), 2-(iv), 3-(ii), 4-(iii).
B : 1-(iv), 3-(iii), 2-(i), 4-(ii).
C : 2-(i), 3-(iv), 4-(iii), 1-(ii).
D : 3-(iv), 2-(iii), 1-(i), 4-(ii).
1-(i), 2-(iv), 3-(ii), 4-(iii).
Q.62 – As the temperature is increased, the coefficient of friction
A : Increases.
B : Reduces.
C : Remains unchangeD :
D : Increase or decrease based on the lubrication regime.
Increase or decrease based on the lubrication regime.
Q.63 – Which of the following is a desirable property of boundary lubricant?
A : Dissolvability in lubricating oils.
B : Affinity to metallic surfaces.
C : Low shear strength and high melting point.
D : All of above.
All of above.
Q.64 – The major disadvantage with extreme pressure lubricants is
A : Carcinogenic nature of the lubricant.
B : Low melting point.
C : It is ineffective.
D : All of above.
Carcinogenic nature of the lubricant.
Q.65 – In hydrodynamic lubrication the major source of friction is
A : Shearing of lubricant film.
B : Abrasion due to asperities on tribo-surfaces.
C : Abrasion of tribo-surfaces due to free particles.
D : All of the above.
Shearing of lubricant film.
Q.66 – Which of the following statements is true about viscosity?
A : Dynamic viscosity is the ratio of shear stress to the resultant shear rate.
B : Kinematic viscosity is equal to dynamic viscosity divided by density.
C : The CGS unit of dynamic viscosity is Centipoise and CGS unit of kinematic viscosity is
Centistokes.
D : All of above.
All of above.
Q.67 – Film thickness in elastohydrodynamic lubrication depends on
A : Applied load and relative velocity.
B : Lubricant properties.
C : Properties of contacting materials.
D : All of above.
All of above.
Q.68 – Viscosity of multigrade oils
A : Reduces with temperature but at higher sensitivity compare to monograde oil.
B : Increases with temperature but at higher sensitivity compare to monograde oil.
C : Reduces with temperature but at lower sensitivity compare to monograde oil.
D : Increases with temperature but at lower sensitivity compare to monograde oil.
Reduces with temperature but at lower sensitivity compare to monograde oil.
Q.69 – Viscosity Index denotes
A : Relationship between the dynamic and kinematic viscosities.
B : Sensitivity of lubricants viscosity with respect to temperature.
C : Both (a) and (b).
D : There is no sliding and only rolling motion involved between cage and balls.
Sensitivity of lubricants viscosity with respect to temperature.
Q.70 – Which one is the common system for oil classification?
A : SAE (Society of Automobile Engineers).
B : API (American Petroleum Institute).
C : ISO (International Organization for Standardization).
D : All of the above.
All of the above.
Q.71 – Which of the following is not an advantage/benefit of solid lubricant?
A : More effective at high loads.
B : Resistance to deterioration.
C : Good heat dissipation.
D : Highly stable in extreme temperature and environment.
Good heat dissipation.
Q.72 – Out of the following which is NOT an example of solid lubricant?
A : Graphite lubricant.
B : Molybdenum Sulphite lubricant.
C : Polytetrafluoroethylene lubricant.
D : Multigrade lubricant.
Multigrade lubricant.
Q.73 – Which of the following is/are the constituents of grease?
A : Base oil.
B : Additive.
C : Thickness fibre.
D : All of above.
All of above.
Q.74 – Which of the following is NOT the advantage of grease?
A : Remains at application point and adhere to the surface.
B : Less frequent application needeD :
C : Good for inclined/vertical shaft.
D : Good dissipation of heat.
Good dissipation of heat.
Q.75 – Apart from reducing friction and wear, the secondary purpose(s) of lubricants is/are
A : Heat dissipation.
B : Reducing corrosion.
C : Both (a) & (b).
D : None of these.