Question 1: Which of the following is INCORRECT about liquid lubricant shear stress?

A. Shear stress is directly proportional to film thickness.

B. Shear stress is directly proportional to kinematic viscosity.

C. Shear stress is directly proportional to velocity gradient.

D. Shear stress is inversely proportional to lubricant density.

(A)
(B)
(C)
(D)

Question 2: Dynamic viscosity and density of liquid lubricants are 15 mPa.s and 780 kg/m³. Kinematic viscosity (in m²/s) of this lubricant will be:

A. 0.00001123

B. 11.7

C. 0.00054

D. 0.419

(A)
(B)
(C)
(D)

Question 3: Which one of following is INCORRECT?

A. Walther’s equation requires three constants to estimate the operating viscosity.

B. Walther’s equation relates kinematic viscosity with absolute temperature.

C. Walther’s equation relates dynamic viscosity with absolute temperature.

D. Walther’s equation relates kinematic viscosity with operating temperature.

(A)
(B)
(C)
(D)

Question 4: Which one of following is INCORRECT?

A. Stribeck curve relates coefficient of friction to applied load.

B. Stribeck curve relates coefficient of friction to lubricant viscosity.

C. Stribeck curve relates coefficient of friction to operating speed.

D. Stribeck curve relates coefficient of friction to surface hardness.

(A)
(B)
(C)
(D)

Question 5: Stribeck curve helps to find :

A. Boundary lubrication regime.

B. Mixed lubrication regime.

C. Hydrodynamic lubrication regime.

D. All of above.

(A)
(B)
(C)
(D)

Question 6: Viscosity index is measure of change in viscosity with :

A. Temperature.

B. Pressure.

C. Temperature and pressure.

D. Lubricant additives.

(A)
(B)
(C)
(D)

Question 7: Which one the following is the most generic requirement for lubricant :

A. Keep interface shear strength under control.

B. Reduce the temperature rise.

C. Protect the surfaces from aggressive products.

D. Remove residue from the operating surfaces.

(A)
(B)
(C)
(D)

Question 8: Which one of following does not belong to lubricant additive group?

A. Anti-knock improver

B. Viscosity index improver.

C. Corrosion inhibitors.

D. Anti-seizure.

(A)
(B)
(C)
(D)

Question 9: Which one of the following is INCORRECT for boundary lubrication?

A. Solid surfaces are so close together that appreciable contact between opposing asperities occurs and lubricants become ineffective.

B. Friction and wear are determined predominantly by interaction between the solids and between solids and the liquid.

C. Bulk liquid properties of the lubricant play negligible part in friction and wear behaviour.

D. Lubricant film is too thin to provide total solid separation.

(A)
(B)
(C)
(D)

Question 10: Which of the following is CORRECT?

A. NLGI grades express a measure of the relative hardness of grease.

B. Grease is a semi-solid like sponge.

C. Grease is always made of liquid lubricant dispersed in soap based thickener.

D. All of above.

(A)
(B)
(C)
(D)

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